Methods

PARTICIPANTS

Eight male amateur boxers aged 24.9 (3.8) years, height 1.8 (0.07) m (mean (SD)), volunteered to participate in the study and signed informed consent forms. All had participated in the sport for a minimum period of two years. The study received approval from the University College Chichester ethics committee.

MEASURES

Heart rates and blood lactate and glucose concentrations

During boxing performances, heart rate was recorded and stored to memory for subsequent analysis (Polar Sports Tester, Bodycare, Kempele, Finland). Fingerprick (50 μl) capillary blood samples were drawn to determine blood lactate and glucose concentrations (2300 StatPlus; YSI, Ohio, USA). The lactate and glucose automated analyser was calibrated before each experimental trial using 2.5, 5.0, 7.5, and 15 mM lactate and 5.0 and 10.0 mM glucose standards respectively.

Perceived recovery

Boxers were requested to give responses to four items on a 0 (not at all) to 7 (very much so) linear rating scale designed to explore perceptions of recovery (total scores ranged between 0 and 28). Numbers 1 to 6 on this scale were undefined and were used to delineate degrees of perceived recovery between the two ends of the scale. The items were “refreshed”, “recharged”, “rested”, and “recovered”. The scale has good internal consistency (α = 0.86), and face validity of the included items was established through scrutiny by a panel of four British Association of Sport and Exercise Sciences accredited sport psychologists.³⁷ A similar rating scale has been used to assess perceptions of sluggishness and heaviness in athletes.³⁸

Boxing performance

The design, construction, and calibration of the boxing ergometer system has been described in detail.³⁹ Briefly, the ergometer uses matched 9366 force sensors (Kistler, Winterthur, Switzerland) which provide the identification of a pathway of force production for each type of punch due to three dimensional sensitivity. Previous results have indicated that the ergometer is a valid and reliable instrument, and is capable of discriminating between elite, intermediate, and novice boxers in a range of punches.³⁹ In this study, punching force measured in Newtons was recorded. Mean peak force was determined per punch in each round, providing a measure of boxing performance. As the punching protocol was straight lead and rear hand punches either singularly or in two and three punch combinations, the force data collected in the Fz (anterior-posterior) plane was selected for analysis. The Fx (medio-lateral) and Fy (vertical) planes are considered more applicable to force measurement in hook and uppercut punches.³⁹

PROCEDURE

All participants were habituated to punching the boxing ergometer in the two week period before the beginning of the study. Participants maintained a normal diet throughout the experimental period and refrained from intensive training. They entered the laboratory having refrained from physical activity over the previous 48 hours. Each participant's mass (Avery scales, Avery, Birmingham, UK; calibrated ±100 g) was determined before he completed performance 1, a simulated boxing bout which consisted of five two minute rounds, interspersed with one minute seated recovery periods. This comprised eighty straight punches per round, performed in a prescribed sequence from an audio cue. A ten minute self selected warm up comprising stretching, jogging, and hitting hand held coaching pads (Bryan, London, UK) was conducted before the bout simulation. Crepe hand bandages (2.5 m length, 0.05 m width) were worn by each participant underneath competition gloves (284 g; Top Ten, Berlin, Germany).

Immediately after performance 1, participants undertook one of two 20 minute interventions. The interventions were massage and no massage. Massage was applied by the same qualified sports massage therapist and consisted of a standard 20 minute routine encompassing the major muscle groups of the legs (eight minutes), back (two minutes), and shoulders and arms (10 minutes). As available literature on duration of massage sets no established time, the 20 minute routine was chosen to replicate recent studies on massage and exercise recovery.^17,18,20,40 A stopwatch was worn by the therapist to ensure standardisation of time. The order in which the massage techniques were administered to body parts was consistent throughout treatments. The selected routine was designed to target the main muscles used in boxing.⁴¹ Effleurage (30 strokes/min) and petrissage (50–60 strokes/min) massage techniques were used. Effleurage massage consisted of rhythmic pressure strokes along the longitudinal axis of each muscle group in a distal to proximal fashion. Petrissage consisted of kneading and squeezing motions over the muscle mass. Participants received treatment while lying in the prone position followed by the supine position.

In the passive rest intervention, participants lay resting on mats. After the intervention, participants had a further 35 minute rest period, whereupon they completed another self selected warm up, and a second performance, which was a repeated simulation of performance 1. Therefore there was a one hour period between the two boxing performances, the minimum period for domestic amateur boxing competition.

Participants rated themselves on perceived recovery after each intervention. Peak heart rate was recorded after each round in both performances, and blood for lactate and glucose determination was withdrawn immediately before and after performance 1, immediately after the intervention, and immediately before and after performance 2. Figure 1 shows the complete experimental design.

Each participant performed the two trials in a counterbalanced design, separated by a seven day recovery period. Four boxers completed the experimental procedures receiving massage as the first intervention and completed the procedures again seven days later, receiving the rest intervention. The remaining four boxers completed the same procedures receiving interventions in reverse order.

STATISTICAL ANALYSIS

A doubly multivariate multiple analysis of variance with follow up univariate analysis was used to investigate differences in blood lactate and glucose levels between conditions. For heart rates and punching force, repeated measures analysis of variance was used, with Tukey's post hoc test to locate differences between the means. A Wilcoxon matched pairs test was employed for perceived recovery analysis. A probability level of 0.05 was used to ascertain significance. Finally, a Pearson's product correlation analysis was used to assess the relation between perceived recovery and blood lactate.

Results

BODY MASS

A paired t test (two tailed) showed no significant differences between interventions for body mass before performance 1 (massage, 78.17 (8.16) kg; passive rest, 78.27 (9.11) kg; t₇ = −0.43, p>0.05).

HEART RATES AND BLOOD LACTATE AND GLUCOSE CONCENTRATIONS

Heart rates (table 1) were examined using a 2 (intervention) × 2 (performance) × 5 (round) repeated measures analysis of variance, with all independent variables as repeated measures. This showed a significant main effect for round (round 1<rounds 2–5, F_4,28 = 44.35, p<0.0001), but no main effects for intervention (F_1,7 = 0.4, p>0.05) or performance (F_1,7 = 4.12, p>0.05). No significant two way or three way interactions were found (p>0.05).

Blood lactate (fig 2) and glucose (table 2) were analysed by a doubly multivariate multiple analysis of variance. This showed a significant time × intervention interaction, λ = 0.41 (F_8,54 = 3.72, p<0.005). Follow up univariate analysis showed that both lactate (F_4,28 = 5.68, p<0.005) and glucose (F_4,28 = 3.72, p<0.05) contributed to the results. Post hoc Tukey analysis showed that blood lactate levels were higher for the massage intervention than for the passive rest intervention after performance 2 (fig 2). All other sampling points showed no differences between interventions. Post hoc Tukey analysis of blood glucose means disclosed no differences between the massage and passive rest interventions at each of the sampling points.

PERCEIVED RECOVERY

Analysis of perceived recovery with a Wilcoxon matched pairs test (one tailed) showed a significant difference between interventions (massage, 19.0 (3.8); passive rest, 12.1 (4.0); Z = −2.38, p<0.01).

BOXING PERFORMANCE

Punching force (table 3) was analysed with a 2 (intervention) × 2 (performance) × 5 (round) repeated measures analysis of variance, with all independent variables as repeated measures factors. Significant main effects were found for performance (performance 1>performance 2, F_1,7 = 7.31, p<0.05) and round (round 1<rounds 2–5, F_4,28= 6.38, p<0.001). No significant main effects were found for intervention (F_1,7 = 0.31, p>0.05). Analysis of interaction effects showed that only the performance × round interaction was significant (F_4,28 = 4.59, p<0.01). Post hoc Tukey analyses showed lower punching force values in performance 2 round 1 than in performance 1 rounds 2 to 5. Finally, the two and three way interactions involving intervention were all non-significant (p>0.05).

RELATION BETWEEN BLOOD LACTATE AND PERCEIVED RECOVERY

To assess the relation between psychological and physiological variables, perceptions of recovery and the blood lactate response after performance 2 were subjected to correlational analysis (fig 3). This showed a significant positive relation (r = 0.50, p<0.05).

Discussion

The major finding of this study is that massage did not affect repeated sports performance. This supports the work of Drews et al,³⁴ who found no change in repeated cycling performance after massage treatment. Boxing has different physiological demands from cycling, and hence these findings of no effect on performance may permit generalisation to other sports with similar demands. The results showed a mean reduction in punching force in performance 2 in both conditions, hence in this case massage was unable to prevent a decrement in repeated performance. However, the finding of no difference between experimental conditions in performance 2 also supports the conclusion that massage does not have detrimental effects on performance.²⁸

Nevertheless, there was evidence of individual variability which appears to have contributed to a finding of no difference in punching force between conditions in the second performance. Although it is evident that there is a trend in group means towards greater punching force in performance 2 after massage, it should be noted that a similar trend of higher mean scores in the massage condition existed in performance 1 before any intervention. Moreover, the observed mean differences in punching force can be argued to be so small (14–70 N) that they are of little clinical relevance or practical value to the boxer.

Much of the physiological basis of massage use in sport is argued to be anecdotal evidence,⁷ hence this study also provides scientific evidence of the lack of influence of massage on physiological recovery from exercise. This research into the blood lactate response to massage supports other studies that have documented no differences between massage and passive rest conditions.^18–20 Therefore only one previous study found that massage led to superior lactate removal over passive rest.¹⁷ The reasons for this isolated finding are not clear, although it is possible that the high resting blood lactate levels recorded in that study may have influenced the results. It is widely acknowledged that blood lactate is removed more quickly during active recovery because blood flow remains elevated through the active muscles, which enhances both lactate diffusion out of the muscles and its oxidation.²¹ Thus the physiological basis of more rapid lactate removal stimulated by massage is increased blood flow.⁶ As the exact effects of massage on blood flow are still being debated,^8–11 blood flow was not measured in this study. Nevertheless, the present finding of no effect of massage on blood lactate would suggest that either blood flow was not affected or that it was not increased sufficiently to enhance lactate removal.

The discovery that perceptions of recovery showed significant changes after massage gives some scientific support for the use of massage as a recovery strategy. A number of authors have argued that the benefits of massage are more psychological than physiological,^7,11,32 and the finding of no physiological effects in this study supports such claims. Few explanations have been suggested with regard to potential pathways for massage to enhance positive affect. One study found a 16% increase in plasma endorphin concentration after massage, and it was suggested that the release of endorphins may explain the sensation of wellbeing following massage.⁴² In addition, it has been proposed that massage could promote a feeling of wellbeing through decreased arousal levels.⁴³

The process of monitoring for perceived recovery after each intervention also provided a new dimension to the study of psychological recovery after massage. Previous authors have suggested the use of new monitoring tools to evaluate different aspects of psychological recovery in athletes.⁴⁴ Suitably, the four item section on perceptions of recovery was designed with these comments in mind, and also a similar 0–7 rating scale has been used to measure perceptions of muscle fatigue/soreness and tiredness in athletes.³⁸ The results obtained in this study point to powerful effects of massage on perceived recovery; however, these findings should be taken as preliminary evidence and further research is needed to document the use of this scale.

The need for interdisciplinary research to explain aspects of recovery has been highlighted previously,⁴⁵ and the combination of psychological and physiological measures used in this investigation may shed more light on the significantly higher blood lactate levels after performance 2 in the massage condition, a finding that could not be explained by differences in the availability of glucose as an energy source between conditions. Here it could be argued that the psychological benefits gained through massage may have resulted in boxers expending greater physical effort in the second performance. Correlational analysis partially supports such a proposition, with perceived recovery being significantly related to blood lactate concentration after performance 2 (r = 0.50). Nevertheless, submaximal heart rates were not elevated in the second performance after the massage intervention, and moreover there was no increase in boxing performance.

The finding that punching force was significantly lower in round 1 than in rounds 2–5 could be explained by an insufficient warm up by the boxers in this study. Heart rate data showed lower values in round 1 than in later rounds, which also indicates that the routine chosen by boxers may not have adequately prepared them for the performance ahead. In practical terms, this information may be useful to boxers and coaches alike, as it shows that the force of the punches could be compromised in the early part of a contest if the warm up is in any way neglected.

In conclusion, this study has documented some evidence of psychological regeneration following massage. However, the efficacy of massage for promoting blood lactate removal after a boxing performance has been questioned, as has the use of massage as a performance enhancement modality. Therefore the use of massage for the latter purposes when repeated performances are required in amateur boxing in one day would not seem to be justified. Finally, it has been suggested that some relation may exist between the proposed psychological benefits of massage in the recovery phase and aspects of repeated sport performance.