Objective: The purpose of the present study was to conduct a process analysis of the effects of personality on physical activity intention and behaviour using the Theory of Planned Behaviour (TPB).
Design: Prospective study design with data collected by means of two questionnaires.
Methods: Data were obtained by means of two questionnaires, the initial questionnaire measured demographic characteristics, TPB constructs, physical activity intention and personality. The two week follow up questionnaire assessed self-report physical activity behaviour. A number of regression analysis were undertaken to identify the relationship between the variables and to determine mediation effects of the TPB constructs.
Patients: A random sample of individuals with Type II Diabetes was selected from the Diabetes Australia (Queensland) membership database. A total of 74 complete data sets were obtained.
Results: Intention explained 28 percent of the variance in physical activity behaviour. Attitude, subjective norm and PBC explained 73 percent of variance in physical activity intention. Attitude and PBC mediated the relationship between conscientiousness and physical activity intention.
Conclusions: These results provide preliminary evidence that targeting constructs proximal to the behaviour (attitudes and PBC) may be effective in overcoming inherent qualities such as personality in order to produce physical activity behaviour change within this sample population.
]]>Objective: To describe the contribution of changes in fitness and fatness resulting from exercise training on changes in submaximal exercise blood pressure (BP) during treadmill testing.
Design and Setting: Prospective, randomized, controlled trial.
Participants: Sedentary older adults (n=115), with untreated prehypertension or mild hypertension.
Interventions: Six-month supervised aerobic and strength training.
Main Outcome Measurement: BP was assessed at rest and during each stage of a maximal graded exercise test (GXT) that determined VO2peak. General and regional fatness was assessed by anthropometry, dual-energy x-ray absorptiometry, and magnetic resonance imaging. BP changes were calculated for each GXT stage and multivariate regression models were used to describe the association of changes in exercise BP with changes in fitness and fatness.
Results: After training, exercisers versus controls had significantly increased VO2peak and significantly lower measures of general and regional fatness. Also, stage-specific SBP was significantly lower at stage 3 (-9.4 vs. -1.6 mmHg, p=0.03) and stage 4 (-7.9 vs. -1.2 mmHg, p=0.03). Pooled regression analysis across all stages showed that exercisers had a 7.1 mmHg reduction in SBP, but this reduction fell short of statistical significance (p=0.12) compared to controls. A 1.0 ml/kg/min increase in VO2peak and a 1.0 cm decrease in waist circumference independently predicted a 1.0 mmHg decrease in exercise SBP (p=0.04 and p=0.001, respectively).
Conclusions: Decreased exercise SBP was independently associated with decreased waist circumference, a marker of abdominal obesity, and increased fitness. Our findings suggest that exercise training improves multiple factors that have independent influence on SBP.
]]>Background: sCD40L is a powerful marker of cardiovascular risk. Exercise is known to decrease cardiovascular risk, but the impact of ultra-endurance exercise on sCD40L responses is unknown.
Objective: To examine the relationship between ultra-endurance exercise in trained athletes and levels of sCD40L and its natural ligand sCD40.
Design: Control-trial, cross-over design, exercise intervention study of sCD40L and sCD40 levels.
Setting: Outdoor exercise and laboratory testing, single centre study, School of Physical Education, University of Otago, New Zealand.
Participants: Nine trained ultra-endurance athletes.
Interventions: Athletes exercised (cycled and jogged) for 17 of 24 hours. Venous blood was sampled at baseline and serially throughout exercise and 24 and 48 hours after exercise. The athletes completed a 24-hour control trial on a separate occasion, in randomised order.
Main outcome measurements: Mean levels of sCD40L and sCD40 during exercise and rest with 95% confidence intervals.
Results: sCD40L levels dropped steadily from baseline (median 4128 pg/ml) to a measured nadir at 24 hours following exercise (median 1409 pg/ml) (p= 0.01). The levels had started to rise again by 48 hours after exercise. When measured as a group, sCD40L levels remained constant during a control rest period. sCD40 levels remained constant on both exercise and control days.
Conclusion: Ultra-endurance exercise lowers the levels of the cardiovascular risk marker sCD40L in athletes. These results raise the possibility that exercise induced changes in sCD40L may provide one of the mechanisms by which exercise lowers cardiovascular risk.
]]>Objective: An increase in knee laxity during the menstrual cycle may increase the risk of ACL injury. The objective of this study was to investigate whether changing knee laxity during the menstrual cycle is correlated with changing knee joint loads in a cutting maneuver.
Design: Cross sectional study.
Setting: Laboratory testing
Participants: Twenty-five healthy females, with a normal menstrual cycle, no history of oral contraceptive use and no previous knee injury.
Interventions: Serum hormone levels were assessed and knee joint laxity at a load of 89N was measured during the follicular, ovulation and luteal phases. Participants performed 10 trials of a cutting maneuver to quantify knee joint mechanics at each test session.
Main outcome measurements: Knee joint laxity (mm), peak knee angle (°) and knee joint moment (Nm) and knee joint impulse (Nms).
Results: Increased knee laxity was observed during ovulation compared to the luteal phase while no significant changes in knee mechanics corresponding to menstrual phases were found. A positive correlation was found between changes in knee laxity (laxity) and changes in knee joint loads (moment or impulse) from the follicular phase to ovulation, and from ovulation to the luteal phase (P<0.05). Females who increased knee laxity showed increased knee loads while others who decreased knee laxity showed decreased knee loads during the menstrual cycle.
Conclusion: Knee laxity is positively correlated with knee joint loads, and increased knee laxity during the menstrual cycle may be a potential risk factor for ACL injuries in specific females during sports activity.
]]>Objective: To examine factors associated with tackles in rugby union and to assess their impact on the risk of injury.
Design: 2-season (2003/2004 and 2005/2006) prospective cohort design with video analysis.
Setting: 13 English Premiership clubs.
Participants: 645 players.
Main outcome measure: Relative risk (95% confidence interval) calculated by comparing the frequency of occurrence of risk factors in a cohort of players injured during tackles with their frequency of occurrence in tackles in general play.
Risk factors: Playing position; player’s speed, impact force, head position, head/neck flexion and body region struck in the tackle; sequence, direction and type of tackle; and location and type of injury.
Results: High speed going into the tackle, high impact force, collisions and contact with a player’s head/neck were identified as significant (p<0.01) risk factors for ball carriers and tacklers. Midfield backs were significantly (p<0.01) more prone to injury when tackling than other players. Relatively few tacklers were penalised by referees for collision tackles (general play: 2.0%; injured players: 3.3%) and tackles above the line of the shoulder (general play: 5.9%; injured players: 16.7%).
Conclusions: Advice in national and international injury prevention programmes for reducing the risk of injury in tackles is strongly supported by the results obtained from this study. These programmes should be reviewed, however, to provide specific advice for each type of tackle. Stricter implementation of the Laws of Rugby relating to collisions and tackles above the line of the shoulder may reduce the number of head/neck injuries sustained by ball carriers.
]]>Objective: The purpose of this study was to investigate if the knee joint dynamics during a forward lunge could be modulated by experimentally induced vastus medialis pain in healthy subjects.
Design: Randomized cross-over study.
Settings: Biomechanical movement laboratory.
Participants: Twenty healthy subjects were included. One subject were excluded during data collection.
Intervention: The subjects performed forward lunges before, during and 20 minutes after induction of experimental quadriceps muscle pain. Muscle pain was induced using hypertonic saline (5.8 %) injected intramuscularly. Isotonic saline (0.9%) was used as control.
Main outcome measurements: Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. EMG signals of the hamstrings and quadriceps muscles were recorded.
Results: During and after pain, significant decreases in knee joint dynamics and EMG recordings were observed.
Conclusion: The study shows that local pain in the quadriceps is capable of modulating movements with high knee joint dynamics. The results may have implications in the management of muscle pain and prevention of injuries during activities involving the knee joint.
]]>Objective: The aim of this study was to assess the clinical effect of antibiotic treatment in a cohort of patients with low back pain (LBP) and Modic changes Type 1 (bone oedema) following a lumbar herniated disc.
Design: This was a prospective uncontrolled trial of 32 LBP patients who had Modic changes and were treated with Amoxicillin-clavulanate (500 mg/125 mg) 3 x day for 90 days. All patients had previously participated in a randomized controlled trial (RCT) that investigated active conservative treatment for a lumbar herniated disc (n=166). All patients in that RCT who had Modic changes and LBP at 14 months follow-up (n=37) were invited to participate in this subsequent antibiotic trial but five did not meet the inclusion criteria.
Results: Twenty-nine patients completed the treatment, as three patients dropped out due to severe diarrhoea. At the end of treatment and at long-term follow-up (mean 10.8 months) there was both a clinically important and statistically significant (p< 0.001) improvement in all outcome measures: LBP intensity, number of days with pain, disease- and patient-specific function, and global perceived effect.
Conclusions: In this uncontrolled trial, the clinical effect of antibiotic treatment was large in a group of patients with Modic changes suffering from persistent LBP following a disc herniation. These results provide tentative support for a hypothesis that bacterial infection may play a role in LBP with Modic changes and indicate the need for randomised controlled trials to test this hypothesis.
]]>A recent and controversial review 1 suggests that the measurement of maximal oxygen intake is passé. The author concludes (p. 554) "It is now time to develop novel testing methods....That the measured VO2max is a relatively poor predictor of both the performance potential of athletes with similar athletic ability and of the changes in performance that occur with continued training should encourage both basic and applied sports scientists to reconsider the real value of this iconic test."
A number of the arguments that are advanced in this review seem to need to correction or refutation. Specifically, this riposte will examine whether a maximal treadmill test is an unrealistic procedure for athletes, whether a unimodal approach to testing is appropriate in sports medicine, and whether an alternative laboratory test will be developed to categorize the performance of individual athletes. Comments will also be made on the place of maximal oxygen intake assessment in various areas of science, sports medicine and clinical medicine.
]]>Healthcare providers have become more aware of and concerned about pediatric sudden cardiac arrest. The diseases predisposing a patient to sudden cardiac arrest are all infrequently encountered. However, a detailed and comprehensive patient and family history may reveal warning signs and symptoms that identify a patient at higher risk for sudden cardiac arrest. Since many of these diseases are genetic, extensive family evaluation may uncover a previously undetected cardiac disease process and as well direct the development of a complete family evaluation and treatment plan. Published data document that in many cases preceding warning symptoms and signs are present, but may be misinterpreted or disregarded by medical staff. Attention to the details of patient history, family history, and physical exam is critical to the success of any detection strategy, which can and should be widely applied.
]]>Background and purpose: Extracorporeal shockwave therapy has become a popular treatment for patellar tendinopathy. The purpose of this review was to study the effectiveness of ESWT treatment for patellar tendinopathy and to draft guidelines for an effective treatment protocol of ESWT treatment. We also want to identify topics for further research.
Methods: A computerized search of the Medline and Embase databases was conducted on August 1, 2007, to identify studies dealing with the effectiveness of ESWT for patellar tendinopathy.
Results: We included seven articles describing the effectiveness of ESWT on patellar tendinopathy, all published after 2000. These studies included a total of 283 patients (298 tendons), 204 of whom (215 tendons) were assigned to ESWT treatment. The treatment results were positive but most studies had methodological deficiencies, small numbers and/or short follow-up periods. Method of application and shockwave generation, energy level, number and frequency of treatments, use of (local) anaesthesia and method of localization were variable.
Conclusion: ESWT seems to be a safe and promising treatment for patellar tendinopathy with a positive effect on pain and function. Based on the current knowledge it is impossible to recommend a specific treatment protocol. Further basic and clinical research into the working mechanism and effectiveness of ESWT for patellar tendinopathy are necessary.
]]>Objective: The functional 577R allele of the -actinin-3 (ACTN3) gene has been reported to be associated with elite power athlete status, while the nonfunctional 577XX genotype (predicts an -actinin-3 deficient phenotype) has been hypothesized as providing some sort of advantage for endurance athletes. In the present study we examined the distribution of ACTN3 genotypes and alleles in Russian endurance-oriented athletes and looked for association between ACTN3 genotypes and the competition results of rowers.
Methods: The study involved 456 Russian endurance-oriented athletes of regional or national competitive standard. ACTN3 genotype and allele frequencies were compared to 1,211 controls. The data from the Russian Cup Rowing Tournament were used to search for possible association between the ACTN3 genotype and the long-distance (~~ 6 km) rowing results of 54 athletes. DNA was extracted from mouthwash samples. Genotyping for the R577X variant was performed by PCR and restriction enzyme digestion.
Results: The frequencies of the ACTN3 577XX genotype (5.7% vs. 14.5%; P < 0.0001) and 577X allele (33.2% vs. 39.0%; P = 0.0025) were significantly lower in endurance-oriented athletes compared to the controls, and none of the highly elite athletes had the 577XX genotype. Furthermore, male rowers with ACTN3 577RR genotype showed better results (1339 ± 11 s) in long-distance rowing than carriers of 577RX (1386 ± 12 s) or 577XX (1402 ± 10 s) genotypes (P=0.016).
Conclusion: Our data show that the ACTN3 577X allele is underrepresented in Russian endurance athletes and is associated with the rowers’ competition results.
]]>How do health care providers know if their patients are getting enough physical activity to promote good health and to reduce their risks for chronic diseases and injury? The first step is to identify the patient's current level of physical activity using questionnaires and/or motion sensors. Questionnaires assess activity levels by having patients answer a set of questions about the types and amounts of activity performed at some time in the past. Motion sensors assess physical activity by patients wearing a small monitoring device that records their body movement as it occurs. If a provider is interested in determining a patient's caloric energy expenditure, he/she can apply statistical regression models to the questionnaire and motion sensor data to estimate kilocalories. If more precise measures of energy expenditure are desired, a provider can use the isotopic doubly-labeled water methods to estimate kilocalories, however this method is costly and is impractical in non-research clinical settings.
]]>Objective: To describe injury incidence and association with type and volume of training in international rowers.
Design: A prospective cohort design was used over a 12 month period.
Patients: 20 international rowers who were competing as part of the Irish Amateur rowing Union squad system.
Methods: The rowers were interviewed monthly and data was collected regarding their training and competition exposure as well as their injury experience.
Results: A mean injury rate of 3.67 per 1000 exposure hours was reported with a total of 44 injuries reported in a 12 month period. The mean number of injuries sustained per athlete was 2.2 (1.24) over the 12 month period. The area where the greatest number of injuries were reported was the lumbar spine (31.82% of total injuries, 95% CI, 20-50) (Figure 2) followed by the knee (15.91% of total injuries, 95% CI, 10-30) and the cervical spine (11.36% of total injuries, 95% CI, 5-24). Half of the injuries (22 injuries, 50% of total reported injuries) were to the spine. (2 = 30.8, df = 9, P = 0.0003). Ergometer training load was the most significantly associated with injury risk (r = 0.68, P = 0.01).
Conclusion: International rowers are at higher risk of injury than most non-contact sports and some contact sports. The high risk of lumbar spine injury and the significant association of high volume of ergometer training merit further research to reduce time and competition lost to injury.
]]>Objective: To investigate early clinical predictors of time to return to competition and of recurrence following hamstring strain.
Design: Prospective observational study.
Setting: Elite level of Australian Football competition.
Participants: 59 players who suffered a hamstring strain in 2002 season.
Predictors: Clinical assessment by a physiotherapist and questionnaire.
Main outcome measures: Time taken to return to play and recurrence of hamstring injury within 3 weeks.
Results: Players taking more than one day to walk pain-free were significantly more likely to take longer than three weeks to return to competition (AOR 4.0; 95% CI 1.3, 12.6; p=0.018). Nine players (15.2%) experienced an injury recurrence; all involving the biceps femoris. Recurrence was more likely in players who reported a hamstring injury in past 12 months (AOR 19.6; 95% CI: 1.5, 261.0; p=0.025).
Conclusion: Time to walk pain-free and previous hamstring injury are predictors of time to return to competition and recurrence, respectively, and should be included in a clinical assessment to aid in prognosis.
]]>Objective: To study if a two bout exercise protocol can be used to make an objective, immediately available distinction between non-functional overreaching (NFO) and overtraining syndrome (OTS).
Design: Underperforming athletes who were diagnosed with the suspicion of NFO or OTS were included in the study. Recovery of the athletes was monitored by a sports physician to retrospectively distinguish NFO from OTS.
Setting: Sports medicine laboratory.
Participants: Ten underperforming athletes started and completed the protocol. Five athletes were retrospectively diagnosed with NFO and five were diagnosed with OTS.
Interventions: A two bout maximal exercise protocol was used to measure physical performance and stress induced hormonal reactions.
Main outcome measurements: Exercise duration, heart rate and blood lactate concentration were measured at the end of both exercise tests. Venous concentrations cortisol, adrenocorticotrophic hormone (ACTH), prolactin and growth hormone were measured both before and after both exercise tests.
Results: Maximal blood lactate concentration was lower in OTS compared to NFO, while resting concentrations of cortisol, ACTH and prolactin concentrations were higher. However, sensitivity of these measures was low. The ACTH and prolactin reactions to the second exercise bout were much higher in NFO athletes compared to OTS and showed the highest sensitivity for making the distinction.
]]>Objective: To determine the relative accuracy during treadmill walking and motor vehicle travel of the ActivPALTM, PALliteTM and Digi-WalkerTM accelerometers.
Methods: Forty healthy volunteers wearing all accelerometers undertook either five treadmill walks (n=20) at speeds ranging between 0.6–1.4m/s or a 15min motor vehicle journey (n=20). Step counts recorded by each accelerometer were compared to the actual step count determined by video analysis (treadmill walking) or to an actual step count of zero (motor vehicle). Mean percentage measurement error was calculated and compared between devices by one-way ANOVA and Student's t-test.
Results: For treadmill walking, the measurement error was lowest for the ActivPAL, with no significant differences between the ActivPAL and the PALlite monitors. The measurement error was significantly higher for the Digi-Walker at speeds of ≤1m/s. During vehicle travel erroneous steps were recorded by the PALlite (254 steps) and Digi-Walker (25 steps), but not the AcitvPAL monitor (0 steps).
Conclusions: The ActivPAL accelerometer accurately measures step count over a range of walking speeds and, unlike the other accelerometers tested, is not falsely triggered by motor vehicle travel.
]]>Objective: The osseous ankle configuration (tibiotalar sector, talar radius and height) has been discovered as intrinsic risk factor for chronic ankle instability (CAI). These measurements were done on lateral radiographs only. The aim of this study was to measure osseous characteristics in the frontal plane and further lateral values.
Design: Case control study, Level III.
Setting: Radiological measurement of frontal and lateral radiographs by one independent, blinded radiologist using a digital DICOM/PACS system.
Patients: A group of 52 patients with CAI was compared to an age- and gender-matched control group of 52 healthy subjects.
Main Outcome Measurements: In the frontal plane: the depth of the talar curvature (froCu), the lateral and medial malleolar length. In the lateral plane: the position of the center of rotation to the tibial axis (TibCOR) and the lateral tibial surface angle (TLS).
Results: The froCu was deeper in patients with CAI (1.8±1mm) than in healthy subjects (1.0±0.4mm; P<0.05). The TibCOR was more anterior in patients with CAI (2.4±1.9mm) than in healthy subjects (1.5±2.2mm; P<0.05). The distance from the fibular tip to the center of rotation was smaller in patients with CAI (3.5±3.4mm) than in healthy subjects (6.5±3.3mm; P<0.05). The TLS, the length of the lateral and medial ankle were not significantly different.
Conclusions: This study supports that the osseous joint configuration is an intrinsic risk factor for CAI. It could be shown that CAI is characterized by a deeper frontal curvature of the talus and a more anterior position of the talus to the tibia.
]]>Physical inactivity is an important public health problem, which could be addressed by health promotion initiatives in primary care. The interventions most widely available to primary care clinicians are advice/counselling and exercise referral. A review of four systematic reviews found that brief advice from a general practitioner, supported by written materials has a modest short-term effect on physical activity lasting 6-12 months. Exercise referral schemes have been introduced throughout Wales and the rest of the United Kingdom. A systematic review and meta-analysis found that such schemes resulted in a statistically significant increase in the proportion of sedentary people becoming moderately active, but the absolute risk reduction was small with 17 sedentary people needing to be referred for one to become moderately active. This small effect size could be partly explained by poor rates of uptake and adherence and was not likely to be an efficient use of resources. These findings were in concordance with the guidance from the National Institute of Clinical Excellence, which states that schemes should only be recommended if they are part of a properly designed and controlled research study. Since 2007 a National Exercise Referral Scheme is being rolled out throughout Wales in three phases, and is being evaluated in a pragmatic randomised controlled trial comparing exercise referral with an advice booklet.
]]>Background: Tennis elbow is a tendinopathy affecting the upper extremity. Recent studies have shown high sensitivity for ultrasound (US) examination and high specificity for colour Doppler (CD) examination. There are no mid- or long-term follow-up investigations of the tendon structure and blood flow using these techniques.
Objective: To use US and CD to study structure and blood flow in the extensor origin in patients with tennis elbow treated with intra-tendinous injections.
Design: Follow-up study.
Setting: Sports Medicine Unit, Umeå University.
Patients: Twenty-five patients (twenty-eight elbows), age 46 years (27-66), treated with intratendinous injections due to chronic pain from tennis elbow.
Method: US- and CD-examination of the extensor origin was carried out at inclusion and at follow-up 2 years after intratendinous injection treatment with polidocanol and/or a local anaesthetic.
Main outcome measurements: US (structure) and CD (blood flow) findings.
Results: All patients had structural tendon changes and high blood flow at inclusion when given the injection treatment. At the 2-year follow up, structural tendon changes were seen in 20/28 elbows and high blood flow was seen in 4/28 elbows. The majority of patients with a good clinical result after treatment had no visible blood flow (17/20), but the structural changes showed no relation to a good result (13/20 remaining changes).
Conclusions: Doppler findings, but not structure, might be related to the clinical result after intra-tendinous injection treatment of tennis elbow.
]]>The cross-country World championship is one of the best models to study characteristics needed to achieve top-level endurance athletic capacity. We report the genotype combination of a recent cross-country champion (12km race) in polymorphisms of seven genes that are candidates to influence endurance phenotype traits (ACTN3, ACE, PPARGC1A, AMPD1, CKMM, GDF8 (myostatin) and HFE). His data were compared with those of eight other runners (World class but not World champions). The only athlete with the theoretically more suited genotype for attaining World-class endurance running performance was the case study subject. A favourable genetic endowment, together with exceptional environmental factors (years of altitude living and training in this case) seems to be necessary to attain the highest possible level of running endurance performance.
]]>Objective: To examine temporal trends in participation in sport and exercise activities (SPEX) in England between 1997 and 2006 while taking into account wider societal changes.
Design: A series of annual cross-sectional surveys. Setting & participants: Nationally-representative samples of men (N=27,217) and women (N=33,721) aged ≥16 yrs.
Main outcome measurements: Any (≥once/four weeks) and regular (≥once/week) participation in overall SPEX, and a number of SPEX groupings (e.g. cycling, swimming, gym and fitness club-based activities (G/FC), racket sports) . Time point (1997/98, 2003/04, 2006) was the main dependent variable.
Results: Age-standardised overall regular participation changed from 40.8% in 1997/98 to 41.2% in 2006 in men (multivariable-adjusted participation odds in 2006:OR 1.11, 95%CIs: 1.03-1.19, p<0.001) and from 31.2% to 33.9% in women (1.21, 1.13-1.29, p<0.001). Regular G/FC increased from 17.0% to 19.2% in men (1.19, 1.09-1.30) and from 15.9% to 18.7% in women (1.23, 1.14-1.33), regular running increased from 2.4% to 4.0% in women only (1.84, 1.56-2.18). Overall increases were apparent only in older adults (≥45 years) (1.25, 1.16-1.35, p<0.001). Young men (16-29 yrs) had reduced odds for cycling (0.72, 0.58-0.88, p=0.008), dancing (0.60, 0.45-0.82, p=0.001), running (0.78, 0.64-0.94, p<0.001) and racket sports (0.60, 0.42-0.86, p=0.003). In men increases were pronounced only among men from nonmanual social classes, higher income households and white ethnic backgrounds.
Conclusions: SPEX participation in England has changed between 1997 and 2006 as the result of increases among middle-aged and older adults and decreases among young males. There are no signs that the participation gap between less and more advantaged population groups is narrowing.
]]>Objective: To evaluate the osmotic and non-osmotic regulation of arginine vasopressin (AVP) during endurance cycling
Design: observational study
Setting: 109 km cycle race
Participants: 33 cyclists
Interventions: none
Main Outcome Measurements: plasma sodium concentration ([Na+]), plasma volume (PV) and plasma AVP concentration ([AVP]p)
Results: A 4-fold increase in [AVP]p occurred despite a 2 mmol/L decrease in plasma [Na+] combined with only modest (5%) plasma volume contraction. A significant inverse correlation was noted between [AVP]p Ä versus urine osmolality Ä (r=-0.41; p<0.05) while non-significant inverse correlations were noted between [AVP]p versus both plasma [Na+] Ä and % PV Ä. Four cyclists finished the race with asymptomatic hyponatraemia. The only significant difference between the entire cohort with this subset of athletes was post-race plasma [Na+] (137.7 vs. 133.5 mmol/L; p<0.001) and plasma [Na+] Ä (-1.9 vs. -5.1 mmol/L; p<0.05). The mean pre-race [AVP]p of these four cyclists was just below the minimum detectable limit (0.3 pg/mL) and increased marginally (0.4 pg/mL) despite the decline in plasma [Na+].
Conclusions: Non-osmotic AVP secretion overshadowed the osmotic regulation of [AVP]p during competitive cycling. The modest decrease in plasma volume was not the primary non-osmotic stimulus to AVP. Partial suppression of AVP occurred in four (12%) cyclists who developed hyponatraemia during five hours of riding. Therefore, these results confirm that non-osmotic AVP secretion and EAH does, in fact, occur in cyclists participating in a 109 km cycle race. However, the stimuli to AVP is likely different between cycling versus running.
]]>Background: For a given subject, time in moderate to very vigorous intensity physical activity (MVPA) varies substantially among physical activity monitors.
Objective: The primary objective of the present study was to determine whether time in MVPA recorded with SenseWearTM Pro2 Armband (Armband), ActiGraph, ikcal and ActiReg® is different compared to indirect calorimetry. The secondary objective was to determine whether these activity monitors estimate energy expenditure different compared to indirect calorimetry.
Material and methods: Fourteen men and six women wore the activity monitors and a portable oxygen analyzer for 120 minutes doing a variety of activities of different intensities. Resting metabolic rate (RMR) was measured with indirect calorimetry. The cut off points defining moderate, vigorous and very vigorous intensity were 3, 6 and 9 times RMR.
Results: Armband and ActiGraph overestimated time in MVPA by 2.9 and 2.5% and ikcal and ActiReg® underestimated time in MVPA by 11.6 and 98.7%, respectively. ActiReg® (p=0.004) and ActiGraph (p=0.007) underestimated energy expenditure in MVPA and all monitors underestimated total energy expenditure (by 5 to 21%). Conclusions: Recorded time in MVPA and energy expenditure varies substantially among physical activity monitors. Thus, when comparing physical activity level among studies, it is essential to know the type of physical activity monitor being used.
]]>Objective: To study trends in general practitioners’ knowledge, confidence, and practices in promoting physical activity to patients over a ten year period (1997-2007). Design: Repeated cross sectional population survey. Setting: General practice in New South Wales (Australia). Participants: 646 (40%), 747 (53%), and 511 (64%) general practitioners that were registered in a selection of urban and rural divisions in New South Wales participated in 2007, 2000, and 1997, respectively. Main outcome measures: Self report questionnaire on the general practitioner’s knowledge, confidence, role perception, attendance of continuous professional development, and counselling practice with regard to promoting physical activity in their patients. Results: The majority of general practitioners felt confident in giving physical activity advice and saw it as their role to do so. The proportion of general practitioners with high confidence and role perception increased between 1997 and 2000 (p< 0.001) but remained unchanged thereafter. In 1997, general practitioners were 0.54 times less likely (95%CI 0.42 to 0.69, p< 0.001) to discuss physical activity with more than 10 patients per week than general practitioners in 2007. However, the percentage of new patients that were asked about their physical activity did not change over the last decade. Conclusions: Most increases in the proportion of general practitioners reporting high knowledge, role perception, and confidence in giving physical activity advice to patients occurred between 1997 and 2000, and remained unchanged thereafter. In 2007, general practitioners appeared to give more physical activity advice, but Australian general practice is not yet living up to its potential with regard to physical activity promotion.
]]>Objectives: To compare serum levels of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) between patients with a history of Achilles tendon rupture and blood donor controls, and to relate MMPs and TIMPs to mechanical properties of the tendons during healing.
Methods: More than three years after injury, we measured serum levels of MMP-1, -2, -3, -7, -8, -9 and -13 and TIMP-1 and -2 in eight patients who had suffered Achilles tendon rupture. Twelve blood donors served as controls. During the early phase of healing, the tendon modulus of elasticity was calculated from radiostereometric data and tendon cross-sectional area.
Results: Patients with a history of Achilles tendon rupture had increased levels of MMP-2 (median difference (m.d.) 10 %; p = 0.01), MMP-7 (m.d. 15 %; p = 0.02) and TIMP-2 (m.d. 36%; p = 0.02), as compared to controls. Levels of MMP-7, measured three years after injury, correlated inversely to tendon modulus of elasticity (rs = -0.83; p = 0.02), and positively to tendon elongation (rs = 0.74; p = 0.05) during the early phase of healing. There was a trend towards positive correlation between MMP-7 and cross-sectional area during the early phase of healing (rs = 0.67; p = 0.08).
Conclusions: Patients with a history of Achilles tendon rupture appear to have elevated levels of MMP-2, MMP-7 and TIMP-2 in serum. These pilot data support the view that the MMP-TIMP system is involved in tendinopathy and suggest that disturbances in proteolytic control might be generalised.
]]>Numerous research studies performed in ‘lab-gyms’ with supervised training have demonstrated that simple, brief (20-30 min) resistance training protocols performed 2-3/wk following the American College of Sports Medicine’s guidelines positively affect risk factors associated with heart disease, cancers, diabetes, sarcopenia and other disabilities. For more than a decade, resistance training has been recommended for adults, particularly older adults, as a prime preventive intervention, and increasing the prevalence of resistance training is an objective of Healthy People 2010. However, the prevalence rate for resistance training is only estimated at 10-15% for older adults, despite the leisure time of older adults and access to facilities in developed countries. The reasons that the prevalence rate remains low include public health policy not emphasizing resistance training, misinformation, and the lack of theoretically driven approaches demonstrating effective transfer and maintenance of training to minimally supervised settings once initial, generally successful, supervised training is completed. Social cognitive theory (SCT) has been applied to physical activity and aerobic training with some success, but there are aspects of resistance training that are unique including its intensity, progression, precision, and time and place specificity. Social cognitive theory, particularly with a focus on self-regulation and response expectancy and affect within an ecological context, can be directly applied to these unique aspects of resistance training for long-term maintenance.
]]>Background: Patellofemoral pain syndrome(PFPS)is a common clinical presentation. Various neuromuscular factors have been reported to contribute to its aetiology.
Study design: Systematic review.
Methods: A literature search was carried out from 1998 up to December 2007. Eligible studies were those that (1)which examined the effects of hip strengthening in subjects with PFPS, (2)examined the effects of physiotherapy treatment aimed at restoring muscle balance between the VMO and VL in subjects with PFPS, (3)examined the effect of taping on EMG muscle amplitude in subjects with PFPS, and (4)compared the effects of open versus closed kinetic chain exercises in the treatment of subjects with PFPS.
Results: No RCTs exist to support the use of hip joint strengthening in subjects with PFPS. Physiotherapy treatment programmes appear to be an efficacious method of improving quadriceps muscle imbalances. Further studies are required to determine the true efficacy of therapeutic patellar taping. Both open and closed kinetic chain exercises are appropriate form of treatment for subjets with PFPS.
]]>Objective Measuring physical activity is a key part of studying its health effects. Questionnaires and pedometers each have weaknesses but are the cheapest and easiest to use measurement methods for large scale studies. We examined their capacity to detect expected associations between physical activity and a range of surrogate health measures.
Design Cross sectional analysis of 669 community dwelling participants (mean age 63.3 ± 7.7 years) who completed the Physical Activity Scale for the Elderly "PASE" questionnaire and, within 2 weeks, wore a pedometer for seven days.
Results PASE score and step count were only poorly correlated, r=0.37 in women, r= 0.30 in men. Of 12 expected associations examined between activity and surrogate markers of health, ten were detected as statistically significant by step counts but only 3 by PASE scores. Significant associations in the expected direction were found between step counts and high density lipoprotein, body mass index (BMI), waist circumference (WC), waist hip ratio (WHR), blood glucose level, white cell count, and fibrinogen. There was no association with either systolic or diastolic blood pressure. The association between PASE score and these markers was detected as significant only for BMI and WC in women, and WHR in both sexes. Associations were stronger for steps multiplied by stride length than for raw step count.
Conclusions Pedometer derived step counts are a more valid measurement of overall physical activity in this sample than PASE score. Researchers should use objective measures of physical activity whenever possible.
]]>This review summarizes existing knowledge regarding sports hernia pathogenesis, differential diagnosis, conservative treatment, surgery, and post-surgical rehabilitation. Sports hernias occur more frequently in males during athletic activities that involve cutting, pivoting, kicking, and sharp turns such as those that occur during soccer, ice hockey, or football. Sports hernias generally present an insidious onset; however with focused questioning a specific inciting incident may be identified. The likely causative factor is posterior inguinal wall weakening from excessive or high repetition shear forces applied through the pelvic attachments of poorly balanced hip adductor and abdominal muscle activation. There is currently no consensus as to what specifically constitutes this diagnosis. Since it can be difficult to make a definitive diagnosis based on conventional physical examination, other modalities such as MRI and diagnostic ultrasound are often employed, primarily to rule out other conditions. Surgery appears to be more effective than conservative treatment and laparoscopic techniques generally enable a quicker recovery time than open repair. However, in addition to better descriptions of surgical anatomy and procedures, and conservative and post-surgical rehabilitation, well-designed research studies are needed with more detailed serial patient outcome measurements in addition to basing success solely on return to sports activity timing. Only with this information will we better understand sports hernia pathogenesis, verify superior surgical approaches, develop evidence-based screening and prevention strategies, and more effectively direct both conservative and post-surgical rehabilitation.
]]>Objectives: To develop a profile of direct catastrophic injuries in international styles of wrestling and to describe possible risk factors.
Design: Survey and retrospective review
Setting: Catastrophic injuries which occurred in wrestling clubs in Iran from July 1998 to June 2005 were identified by contacting several sources. The cases were retrospectively reviewed.
Results: The injuries included were 29 direct injuries (fatalities: 12, non-fatal: 11, and serious: 6).The injury rate was: 1.99 direct catastrophic injuries /100,000 wrestlers/year. The majority of direct injuries occurred during training sessions, with a trend toward more injuries in the low- and middle-weight classes and those who were competing at high performance and experience levels. The takedown position, especially for the attacking wrestler who faces a counter attack, was the most common activity at the time of injury. A list of risk factors was suggested of which ‘performing the wrestling maneuver incorrectly’, ‘inappropriate management of the injury’, ‘lack of the coach supervision’, ‘mat problems’ and ‘lack of restraining the wrestlers in a precarious position’ were the most common risk factors.
Conclusions: Catastrophic wrestling injuries are rare and preventable. Coaches have an essential role in the prevention of these injuries.
]]>Background: There is considerable evidence that respiratory muscle training improves pulmonary function, quality of life and exercise performance in healthy athletic populations. The benefits for wheelchair athletes are less well understood. Therefore, the present study examined the influence of inspiratory muscle training (IMT) upon respiratory function and repetitive propulsive sprint performance in wheelchair basketball players.
Methods: Using a placebo-controlled design, 16 wheelchair athletes were divided to an experimental (IMT; n=8) or placebo (sham-IMT; n=8) group based upon selective grouping criteria. The IMT group performed 30 dynamic breaths, twice daily at a resistance equivalent to 50% Maximum Inspiratory Pressure (MIP) and the sham-IMT group performed 60 slow breaths once a day at 15% MIP for a period of 6 weeks.
Results: The IMT group improved both MIP and MEP (17%, 23% respectively; p ≤0.03). Similar improvements were noted for the sham-IMT group with 23% and 33% from base-line for MIP and MEP respectively (p ≤0.03). There were no significant changes in pulmonary function at rest and any of the performance parameters associated with the repetitive sprint test (sprint and recovery times, HRpeak and peak blood lactate concentration). Reported experiences of using the IMT training device suggested ‘less breathlessness’ and ‘less tightness in the chest during the training’
Conclusions: Although there was no improvement in sprint performance, participants in both the IMT and sham-IMT reported an improved respiratory muscle function and quality of life.
]]>Objective: To compare long term outcome of highly active patients with anterior cruciate ligament ruptures treated operatively versus non-operatively.
Design: We reviewed high level athletes with an anterior cruciate ligament rupture on either MRI or arthroscopic evaluation more than ten years previously, who were treated conservatively. They were pair-matched with patients who had had an anterior cruciate ligament reconstruction with bone-patella-tendon-bone, with respect to; age, gender and Tegner activity score before injury.
Participants: In total 50 patients were pair-matched.
Results: In this study we found no statistical difference between the patients treated conservatively or operatively with respect to osteoarthritis or meniscal lesions of the knee, as well as activity level, objective and subjective functional outcome. The patients who were treated operatively had a significantly better stability of the knee at examination.
Conclusion: We conclude that the instability repair using a bone-patella-tendon-bone anterior cruciate ligament reconstruction is a good knee stabilising operation. Both treatment options however show similar patient outcome at ten year.
]]>BACKGROUND: The core components of physical activity, cardiovascular endurance, muscular strength, balance, and flexibility, can provide many health benefits and potentially slow declines associated with aging. National health authorities have widely promoted aerobic exercise message to the public, although the promotion of resistance training has received far less attention.
OBJECTIVES: The primary aim of this research was to assess the prevalence of resistance training in a sample of adults living in regional Australia.
DESIGN: A Computer -Assisted -Telephone-Interview (CATI) survey (n=1230) conducted by Population Research Laboratory at Central Queensland University performed a survey of Queensland adults in October-November 2006. Respondents were asked to report the frequency with which they engaged in resistance training.
PARTICIPANTS: Respondents were 18 years of age or older that could be contacted by direct-dialled, land-based telephone service. A telephone database using a computer program to select, with replacement, a simple random sample of phone numbers selected respondents.
RESULTS: Almost 14% of the population did some form of gym-based resistance training in the week prior to the survey. There was a significant (p<0.05) reduction in participation levels with age. Participation was highest amongst the youngest 18-34 year olds (23.8%) steadily declining with age to a low of 7% in the 55 years and older age group. There was no significant association between genders and participation in resistance training.
CONCLUSIONS: The findings underscore the need to increase overall education on the benefits of resistance training with an emphasis among targeted adult populations to increase participation in resistance training.
]]>In the past decade there has been a focus on isolated transversus abdominis activation and how it contributes to lumbo-pelvic stability. Not only has this rationale influenced the management of chronic low back pain (LBP), it has also been included in exercises for many other pathologies of the lower and upper limb and also for prophylaxis in pain free subjects.
]]>Background: There is a considerable amount of scientific literature on football, but few studies have focused on referees, despite their key role in this sport. Existing studies focus on the physiological demands and training of referees.
Purpose: To analyse injuries and musculoskeletal complaints in referees and assistant referees selected for the 2006 FIFA World CupTM.
Study design: Retrospective survey and prospective study.
Methods: During the preparation camps for to the 2006 FIFA World CupTM in Germany, all 123 referees selected for the tournament completed a questionnaire on injuries and musculoskeletal complaints. During the tournament, the characteristics and consequences of all injuries and complaints incurred by the 63 officiating referees were documented.
Results: More than 40% of the referees reported having incurred an injury and more than 60% having had musculoskeletal complaints during their career. About 20% of the group reported having suffered from musculoskeletal complaints in the last match. During the World Cup, fourteen referees (22%) incurred an injury and more than 30% had musculoskeletal complaints. This prospectively collected data showed an incidence of 20.8 injuries per 1000 match hours (95% CI: 4.17 to 37.4). The most common acute injuries were hamstring strains, calf strains, and ankle sprains, while the most frequent locations of complaints were the low back, hamstring and knee.
Conclusion: Considering the injury profile, the prevalence of associated musculoskeletal complaints, and the high physiological demands of refereeing, it appears that injury prevention programs should be developed and integrated into the fitness training routine of the referee.
]]>ABSTRACT
Objective
To identify the presence and severity of External Auditory Canal Exostoses (EACE) in a group of white water kayakers related to the duration and intensity of kayaking and the number of ear infections reported.
Design
A community based volunteer cross sectional study was completed with 92 kayakers (69 male, 23 female, mean (SD) age 29.3 (8.72) years) and 65 control volunteers (37 male, 28 female, mean (SD) age 36.9 (14.9) years). Following exclusions 269 individual ears were examined (154 kayaker, 115 control). Participants completed a questionnaire and underwent otoscopic examination. Main outcome measures were the presence and severity of EACE, the duration and frequency of kayaking and self-reported ear infections. Exclusion criteria included other cold water exposure, known ear pathology or poor visualisation of the auditory canal.
Results
The findings demonstrate that 69.5% of kayaker ears and 1.7% of the control group were found to have EACE. Severity of EACE was significantly associated with the duration (p<0.01) and frequency (p<0.05) of kayaking with 90.6% of kayakers that had participated for over 10 years having evidence of EACE. A significant relationship also existed between the number of self-reported ear infections and the severity of EACE (p<0.01).
Conclusion
There is a positive relationship between the duration and frequency of white water kayaking and the presence and severity of EACE and associated ear infections.
]]>Background: regular intensive physical activity is associated with nonpathological changes in cardiac morphology. Differential diagnosis with arrhythmogenic right ventricular cardiomyopathy (ARVC) constitutes a not infrequent problem, especially in athletes showing ventricular arrhythmias with left bundle branch block morphology.
Aim of the study: to assess the different clinical and non invasive instrumental features of subjects affected by ARVC and of athletes. Methods: three groups of subjects (40 ARVC patients, 40 athletes and 40 controls, mean age 27+/- 9 yrs) were examined with family and personal history, physical examination, 12-lead ECG, 24 hour ECG, signal-averaged ECG and 2D-and Doppler echocardiography.
Results: 12-lead ECG was abnormal in 62% of ARVC pts vs 7.5% of athletes and 2.5% of controls (p<0.0001). Ventricular arrhythmias and late potentials were present in 70% and 55 % of ARVC subjects, respectively (vs 5% of athletes and 7.5% of controls, p<0.0001). Left ventricular parietal wall thickness and left ventricular-end diastolic diameters were significantly higher in athletes. Moreover right ventricular (RV) outflow tract, measured on parasternal long axis and at the level of aortic root, was significantly larger in ARVC patients (33.6±4.7 mm vs 29.1±3.4 mm and 35.6±6.8 mm vs 30.1±2.9 mm, p<0.0001) and RV fractional shortening and ejection fraction were significantly lower in ARVC patients compared to athletes (40±7.9% vs 44+/-±10%, p=0.05 and 52.9±8% vs 59.9±4.5%, p<0.0001). A thickened moderator band was found to be present in similar percentage in ARVC patients and athletes.
Conclusion: an accurate clinical and instrumental non invasive evaluation including echocardiography as imaging technique allows to distinguish RV alterations typical of ARVC from those detected in athletes as a consequence of intensive physical activity.
]]>Objective: A meta-analysis is conducted on the effect of overload training on resting heart rate, submaximal and maximal exercise heart rates and on heart rate variability, to determine whether these measures can be used as valid markers of overreaching.
Methods: Six databases were searched using relevant terms and strategies. Criteria for study inclusion were: participants must be competitive athletes; an increased training load intervention must be employed; all necessary data to calculate effect sizes must be available. An arbitrary limit of two weeks was chosen to make the distinction between short term and long term interventions. Dependant variables were heart rate and heart rate variability (during supine rest). Pre–post intervention standardized mean differences (SMD) in heart rate or heart rate variability were calculated, and weighted according to the within– group heterogeneity to develop an overall effect.
Results: In these competitive athletes, short term interventions resulted in a moderate increase in both resting heart rate (SMD=0.55; p=0.01) and LF/HF (SMD=0.52; p=0.02), and a moderate decrease in maximal heart rate (SMD=-0.75; p=0.01). Long term interventions resulted in a small decrease of heart rate during submaximal (SMD=-0.38; p=0.006) and maximal exercise (SMD=-0.33; p=0.007), without alteration of resting values.
Conclusion: The small to moderate amplitude of these alterations limits their clinical usefulness, since expected differences may fall within day-to-day variability of these markers. Consequently, the correct interpretation of heart rate or heart rate variability fluctuations during the training process requires the comparison with other signs and symptoms of overreaching to be meaningful.
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]]>Background: Pre-cooling has been shown to enhance performance in repeated sprint exercise in able-bodied subjects in a hot environment. Spinal cord injury causes thermoregulatory impairment with a detrimental effect on performance. This study assessed whether cooling strategies prior to and during exercise in the heat enhances sprint performance in tetraplegic athletes.
Methods: Eight male tetraplegic athletes performed arm crank intermittent exercise in the heat (32.0 ± 0.1°C, humidity 50 ± 0.1%) for a maximum of 60 min or until exhaustion. Trials involved a no cooling control (CON), pre-cooling (PRE) or cooling during exercise (DUR). Each intermittent sprint protocol consisted of varied periods of passive rest, maximal sprinting and active recovery.
Results: Both PRE and DUR cooling strategies improved the ability of the athletes to repeatedly perform high intensity sprints, with times to exhaustion (TTE) of 47.2 ±10.8 and 52.8 ±5.8 min respectively (P < 0.05). During the CON trial athletes demonstrated a reduction in the total number of sprints they were able to perform (18.13 ± 4.8 sprints; 36.2 ±9.6 min). Core temperature was significantly higher for CON (37.3 ± 0.3°C) when compared to both PRE and DUR (36.5 ± 0.6°C and 37.0 ± 0.5°C respectively; P < 0.01). Ratings of perceived exertion and thermal sensation upon exhaustion or completion were not different.
Conclusions: Tetraplegic athletes should use a pre-cooling or during exercise cooling strategy when performing intermittent sprint exercise in hot conditions to improve performance.
]]>Objective: To examine whether physical activity is independently associated with direct health care costs in community-dwelling older adults with multiple chronic conditions.
Design: Cross-sectional analysis.
Setting: Research laboratory.
Participants: Two hundred and nine community-dwelling men and women volunteers aged 65 years and older with chronic conditions.
Intervention: None.
Main Outcome Measures: Primary dependent variable was direct health care costs incurred in the previous three months. Participants completed the Health Resource Utilization (HRU) questionnaire. To estimate HRU, direct costs in the previous three months were calculated using the third party payer perspective of the British Columbia Ministry of Health, deemed representative of the Canadian health care system costs. For medications, we used the Retail Pharmacy Dispensed prescription cost tables. Primary independent variables were: 1) self-report current level of physical activity as assessed by the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD); and 2) general balance and mobility as assessed by the National Institute on Aging Balance Scale.
Results: The mean number of chronic conditions per participant was six. Current level of physical activity was independently and inversely associated with HRU. Age, gender, number of chronic conditions, global cognitive function, body mass index, and general balance and mobility together accounted for 24.3% of the total variance. Adding PASIPD score resulted in an R-square change of 3.3% and significantly improved the model. The total variance accounted by the final model was 27.6%.
Conclusions: Physical activity promotion may reduce health care costs in older adults with chronic conditions.
]]>Objective: To assess the hydration status of amateur cyclists who voluntarily adjusted their fluid intake to environmental conditions in a three-day, 248 km mountain bike (MTB) race
Design: Prospective observational field study.
Setting: Sani2C MTB Race, KwaZulu-Natal, South Africa, 2006.
Participants: 18 randomly selected amateur, male MTB cyclists
Main Outcome Measures: Reported usual fluid intake, environmental conditions, voluntary fluid intake, urine voided, changes in body mass, serum osmolality (SO), sodium concentration [Na+], and urinary specific gravity (Usg) during each stage (S).
Results: Dry bulb temperature (adjusted for windchill) ranged from 6 - 21.4°C during S1, S2 & S3. While 77.8 % (n =14) of subjects reported a usual intake of >750 ml. hr-1 in previous MTB events, mean (±SEM) fluid intake in this race ranged from 341 (±32) ml. hr-1 during S1 to 551 (±56) ml. hr-1 during S3. Changes in mean body mass ranged between -0.99 and -2.02 % during the three stages. Mean SO and serum [Na+] ranged between 292 (±0.73) and 298 mosm.kg-1 and 137 (±0.35) and 140 (±0.42) meq., respectively, during the three-day period, while Usg remained ≤1.025.
Conclusion: Ad libitum fluid intake during the 2006 Sani2C MTB Race which took place in unexpectedly cold environmental conditions, was slightly below current recommendations and substantially lower than the usual reported fluid intake of subjects. Changes in body mass, SO, serum [Na+] and Usg were not clinically significant, indicating that adequate an hydration status was maintained during the multi-day MTB cycle race.
]]>This study examined the effect of a 5-min cold water immersion (CWI; 14°C) recovery intervention on repeated cycling performance in the heat. Ten male cyclists performed two bouts of a 25-min constant paced (254±22W) cycling session (CP) followed by a 4-km time trial (TT) in hot conditions (35°C, 40% relative humidity). The two bouts were separated by either 15-min of seated recovery in the heat (CON), or the same condition with 5-min CWI (5th-10th min), in a counterbalanced cross-over design (CP1TT1 -> CWI or CON -> CP2TT2). Rectal temperature (Tre) was measured immediately before and after both the CP sessions and 4 km TTs. Cycling economy and VO2 were measured during the CP sessions and the average power output (PO) and completion times (CT) were recorded for each TT. Compared with CON, Tre was significantly lower (0.5±0.4°C) in CWI before CP2 until the end of TT2. However, the increase in Tre (0.5±0.2°C) during CP2 was not significantly different between conditions. During TT2, PO was significantly greater in CWI (327.9 ± 55.7 W) compared with CON (288.0 ± 58.8 W), leading to a faster CT in CWI (6.1 ± 0.3 s) compared with CON (6.4 ± 0.5 s). Economy and VO2 were not influence by the CWI recovery intervention. In conclusion, 5-min CWI recovery significantly lowered Tre and maintained endurance performance during subsequent high-intensity exercise. These data indicate that repeated exercise performance in heat may be improved when a short period of CWI is applied during the recovery period.
]]>Objective: The potential of currently available padded soccer goalkeeper shorts to prevent hip injuries sustained in side jumps was investigated.
Design: Within the scope of this study a survey among professional and amateur goalkeepers, trainers as well as the medical staff was performed. In addition commercially available shorts were impact-tested using an artificial hip model. The results were compared to requirements established for hip protectors for elderly.
Results: As results of the survey it was found that contusions and abrasions were observed most often for all players. Fractures and arthritis were only reported by amateur players, whereas bursitis was more frequently observed by professional players. Amateurs have a significantly higher risk of injury than professional players and the higher injury risk during training is significantly higher compared to the injury risk during a match. No difference of the injury risk was found between goalkeepers wearing padded shorts and those who did not. Impact tests indicated a wide range of performance of the currently available products. The padded shorts generally reduce impact forces, but mostly perform poorly. Only shorts that were made of visco-elastic foam fulfilled the basic requirements requested for hip protectors for elderly.
Conclusions: The quality of most of the currently available goalkeeper shorts needs to be improved in order to effectively prevent hip injury sustained in side jumps.
]]>Background and aims: The validity of five brands of cycle ergometers was evaluated by the comparison of the VO2 requirements at different displayed power.
Methods and results: Five physically active males performed a continuous incremental exercise test on five ergometers (Ergomeca, Lifecycle, Monark, Polar S710 and Computrainer). The latter was also compared with a standard dynamometer in order to associate VO2 values with the real power. Every test started by 5-min warm up on the same cycle-ergometer (Ergomeca) at 100 W to make sure that the VO2 differences do not come from VO2 measurement error. Only last minute steady state VO2 values of each 2-min stage were used for the VO2/Watt curve. Large differences (5 to 10 ml kg-1 min-1) at the same displayed power indicate inaccuracy of displayed power output (PO). Using corrected power values from the dynamometer revealed that for the same VO2 the Computrainer underestimates PO by ~30 W between 100 and 300 W while the Lifecycle overestimate it by 3 to 53 W from 100 to 300 W. The Monark and Polar S710 underestimate PO by 15 W and the Ergomeca by ~5 W.
Conclusion: Inaccuracies between -10 to 18% in displayed PO of various cycle ergometers, question their interchangeability.
]]>Objective: To evaluate the impact of regular training on left ventricle morphology in a group of Bicuspid aortic valve ( BAV ) athletes, considering BAV as a common congenital cardiac condition which is normally compatible with sports activity in the presence of mild aortic regurgitation.
Design: A group of competitive athletes with BAV was followed with a yearly standard echocardiographic examination for five years .
Setting: Sport Medicine Centre, University of Florence, Pre-Partecipation Protocol Study.
Participants: A group of 88 consecutive athletes diagnosed with BAV was followed from January to December 1999 and 30 of these completed a 5-year follow-up. They were compared with a group of 56 athletes with a normal tricuspid valve (TAV).
Results: BAV athletes showed significant progressive increase in left ventricular dimensions and aortic diameters at four levels .The values were within the range of the general and non-athletic BAV populations. In TAV athletes, the aortic and left ventricle dimensions did not increase significantly and remained within physiological range.
Conclusions: Left ventricular measurements in competitive BAV athletes maintain the normal range; there is however a significant progressive increase in the BAV group as compared with the TAV one. Our results are in agreement with data obtained in previous studies on the non-athletic BAV population . Sports activity does not have an additional effect on cardiac morphology in athletes with asymptomatic BAV associated with mild regurgitation, for at least five years.
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