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At the age of 86, I am a strong believer in the virtues of moderate
physical activity for the elderly, walking some 5 km most mornings, and
tending a substantial garden. Moreover, I agree with the proposition that
for an elderly population, any physical activity is better than none, and
that controlled experiments can be devised to demonstrate some of the
short-term benefits of an increase in such activity. However, I w...
At the age of 86, I am a strong believer in the virtues of moderate
physical activity for the elderly, walking some 5 km most mornings, and
tending a substantial garden. Moreover, I agree with the proposition that
for an elderly population, any physical activity is better than none, and
that controlled experiments can be devised to demonstrate some of the
short-term benefits of an increase in such activity. However, I was a
little surprised that the normally eagle-eyed editors and reviewers of
BJSM allowed the current wording of the systematic review and meta-
analysis of low-level physical activity and death rates, as published in
the October issue. In this article, Hupin et al. [1] repeatedly make the
claim that "a dose of MVPA below current recommendations reduced mortality
by 22% in older adults." But it seems clear that the papers cited in
their well-conducted meta-analysis have demonstrated an association
between light physical activity and mortality rather than a causal
reduction in mortality. In most of the investigations considered, the
better initial health of some participants could account for both their
greater habitual activity and also their lower mortality, and the same
problem confounds the analysis of dose-response relationships. We cannot
determine how much physical activity is the cause, and how much it is a
consequence of good health. This is an important issue, and an unfortunate
limitation of much epidemiological research. Partial remedies are to
follow cohorts with differing levels of physical activity for some years
before beginning a study, and to examine the effects of a change in
physical activity over the course of observations.
References
1. Hupin D, Roche F, Gremeaux V. et al. (2015). Even a moderate-to-
vigorous physical activity reduces mortality by 22% in adults aged >60
years; a systematic review and meta-analysis. Br J Sports Med 2015; 49:
1262-1267.
It is common practice to refer lower limb injuries as non-contact, in
this paper the categories have been clearly defined. The term pressing
needs defining which may help the non soccer community.
All lower limb injuries in football ought to be categorised as contact or
in-direct contact with respect to the ground or an opponent. The
principles of the Laws of Motion from Newtonian mechanics and basic
physics might add fur...
It is common practice to refer lower limb injuries as non-contact, in
this paper the categories have been clearly defined. The term pressing
needs defining which may help the non soccer community.
All lower limb injuries in football ought to be categorised as contact or
in-direct contact with respect to the ground or an opponent. The
principles of the Laws of Motion from Newtonian mechanics and basic
physics might add further an understanding of patterns of movement and
relative contact with the ground and the opponent.
References:
Bunn, JW (1972) Scientific principles of coaching. Englewood Cliffs,New
Jersey.
Armenti,A (1992) The Physics of Sports. Springer-Verlag, New York.
Testosterone is one of the anabolic androgen steroids (AAS) that has
been abused to improve higher athletic performance by enhancing muscle
development and recovery. The purpose of this study was to assess basal
level of serum total testosterone in male athletes and to compare it with
physically active and sedentary males.
The study sample was composed of 40
males divided in four groups of different physical acti...
Testosterone is one of the anabolic androgen steroids (AAS) that has
been abused to improve higher athletic performance by enhancing muscle
development and recovery. The purpose of this study was to assess basal
level of serum total testosterone in male athletes and to compare it with
physically active and sedentary males.
The study sample was composed of 40
males divided in four groups of different physical activity level: two
athlete groups (basketball and football), one physically active and one
sedentary group. The subjects were assessed for the level of total
testosterone by Chemiluminescent Immunoassay, controlling for biological
parameters including age, body mass index (BMI), lean body mass (LBM),
diurnal variations. LBM of basketball players (70.2 ? 1.9 kg) was higher
(p < 0.05) than other groups.
Basketball players showed a lower
testosterone level (10.8 ? 1.0) compared with other groups (p < 0.05).
The highest significant difference (p < 0.05) according to basal level
of total testosterone was between basketball players and sedentary (16.7 ?
1.5). Decreased basal level of total testosterone of basketball players
correlates with high LBM in respect to other physically active groups (p
< 0.05). Future suggestion for WADA is to review the upper reference
limit of basal level of total testosterone after the vigorous training
periods for Basketball players
Recent editorials have renewed the debate on the role of physical
inactivity in the current obesity epidemic. [1, 2] Malhotra and colleagues
cite an opinion piece suggesting "little change of physical activity
levels in the past 30 years," while Blair counters that U.S. Dept. of
Labor statistics show "mining, agriculture and agricultural jobs declined
substantially."
Recent editorials have renewed the debate on the role of physical
inactivity in the current obesity epidemic. [1, 2] Malhotra and colleagues
cite an opinion piece suggesting "little change of physical activity
levels in the past 30 years," while Blair counters that U.S. Dept. of
Labor statistics show "mining, agriculture and agricultural jobs declined
substantially."
Both statements have some truth, but they neglect the degree of
energy imbalance needed to make a person obese. In moving from an
acceptable body mass to obesity (BMI > 30 kg/m2), an adult accumulates
about 15 kg of fat, and a child 5 kg. If spread over 10 years, this
equates to 10-30 g/week, or a daily energy imbalance of about 50-150 kJ.
Current statistics lack the accuracy to detect such an imbalance.
Many of the obese are children, unaffected by changes in mining.
However, walking or cycling 1-2 km to and from school is now widely
replaced by transportation in their parents' cars. This could easily
reduce daily energy expenditure by 50-150 kJ.
References
1. Malhotra A, Noakes T, Phinney S. It is time to bust the myth of
physical inactivity and obesity: you cannot outrun a bad diet. Br J Sports
Med 2015; 49: 907-8.
2. Blair SN. Physical inactivity and obesity is not a myth: Dr. Steven
Blair comments on Dr. Aseem Malhotra's editorial. Br J Sports Med 2015;
49: 908-9.
Roy J. Shephard,
PO Box 521,
Brackendale,
BC V0N 1H0,
Canada.
It is like saying Coca-Cola is the favorite drink of many athletes.
The truth is much more complex.
Research in this field that is funded by the beverages industry tends to
be biased.
There will always be people in any field, including scientific research,
who will do almost anything to make a buck.
I can understand the necessity of balancing the views on any public health
issue, but here the balance is tipped over by an ev...
It is like saying Coca-Cola is the favorite drink of many athletes.
The truth is much more complex.
Research in this field that is funded by the beverages industry tends to
be biased.
There will always be people in any field, including scientific research,
who will do almost anything to make a buck.
I can understand the necessity of balancing the views on any public health
issue, but here the balance is tipped over by an evident conflict of
interest.
We thank Prof Cooper for his comments (15th June 2015) on our Letter to the Editor, and in particular his critique of our Point 3. We stated in our original letter that "we invite discussion and criticism of our review, and will gladly amend any sections that can...
We thank Prof Cooper for his comments (15th June 2015) on our Letter to the Editor, and in particular his critique of our Point 3. We stated in our original letter that "we invite discussion and criticism of our review, and will gladly amend any sections that can be shown to be incorrect." In that spirit we will modify our Point 3 accordingly to better reflect the evidence, but we would also like to discuss further the issue that Prof Cooper has raised.
In our letter we pointed to the "Physical Activity Guidelines Advisory Committee Report" in relation to studies showing that physical activity (PA) has an effect on body weight and to challenge the (unreferenced and un-evidenced) claim by Malhotra et al., that "...physical activity does not promote weight loss". The text on page G4-5 to G4-6 of the report clearly describes that from 20 identified RCTs, 4 had appropriate designs and sufficient statistical power to assess weight loss. They showed weight loss of 1-3 kg for 13-26 MET.hours per week, with greater losses at greater doses of PA (1). Presumably Prof Cooper does not dispute this interpretation of the evidence.
We believe the discussion here should focus on the selection of included studies, critique of exposure and outcome measures, and assessment of risk of bias within each study. Debate should also focus on whether 1-3 kg has population level public health relevance as only very large doses of PA resulted in losses greater than the 5% suggested by the report as having clinical relevance.
Perhaps of greatest importance is whether the PA regimens used in these studies could ever be implemented at a population level. On this point we suspect not, and we would highlight again we are sceptical that PA alone is an answer to obesity. It was not our intention to give this impression but to show that the claims of Malhotra et al., did not represent the available evidence. We agree that the evidence suggests diet has a substantially greater effect than PA, and in our original letter we went on to cite further evidence stating that diet plus PA appears to have the greatest effect (2).
Prof Cooper is quite right to say that Figure G4.2 shows that diet has a greater effect than exercise (PA). To directly quote the original study from which the figure was adapted "Randomized trials consistently show benefits of exercise for weight loss, but the effects are often modest" (3). Again we invite debate on the included studies, control conditions used, definition of "modest", and whether these findings have public health relevance - but they clearly contradict the Malhotra claim.
Prof Cooper requests "In the spirit of rigor and honesty I think they should revise their criticism # 3. Even more importantly, they should provide evidence that exercise alone prevents or reduces obesity or they should acknowledge - as the NIH document does - that exercise alone is ineffective."
We have clarified above how the cited report (1) and the 1999 paper it references (3) show that PA (exercise) reduces body weight. We have also submitted an addendum to our Point 3 accordingly to acknowledge that there is debate over the magnitude and clinical relevance of effect, and to emphasise that diet appears to be more effective than PA for reducing obesity. Further, we welcome continued debate on effect, effect size, clinical relevance, study quality, scalability and generalizability. To suggest that the debate on the usefulness of PA is finished is misleading and should be questioned - as Prof Cooper correctly pointed out the Physical Activity Guidelines Advisory Committee Report is equivocal in its interpretation of the evidence. More importantly we also caution against PA only approaches and recommend multi-component approaches combining diet and PA (4).
Finally, we note Prof Cooper refers to "curbing the obesity epidemic". We would point out that this inherently refers to the relative merits of PA and diet in weight maintenance, which is different to weight reduction and has not been the focus of this discussion.
1. Committee PAGA. Physical activity guidelines advisory committee report, 2008. Washington, DC: US Department of Health and Human Services. 2008;2008:A1-H14.
2. Johns DJ, Hartmann-Boyce J, Jebb SA, Aveyard P. Diet or exercise interventions vs combined behavioral weight management programs: a systematic review and meta-analysis of direct comparisons. J AcadNutr Diet. 2014;114(10):1557-68.
3. Wing RR. Physical activity in the treatment of the adulthood overweight and obesity: current evidence and research issues. Medicine and science in sports and exercise. 1999;31(11 Suppl):S547-52.
4. Hunt K, Wyke S, Gray CM, Anderson AS, Brady A, Bunn C, et al. A gender-sensitised weight loss and healthy living programme for overweight and obese men delivered by Scottish Premier League football clubs (FFIT): a pragmatic randomised controlled trial. Lancet (London, England). 2014;383(9924):1211-21.
Conflict of Interest:
We receive funding from a number of national and international research councils, and companies that make devices for physical activity and sedentary behaviour research. We do not receive funding from the food industry.
Kelly et al make a number of useful comments about the unfortunate
editirial by Malhotra et al. However they too obscure the main point.
They use a 2008 NIH document as the key reference to refute the
editorialists' claim that exercise does not lead to weight loss.
What the NIH document actually says -
The magnitude of weight loss due to physical activity is additive to
caloric restriction, but physi...
Kelly et al make a number of useful comments about the unfortunate
editirial by Malhotra et al. However they too obscure the main point.
They use a 2008 NIH document as the key reference to refute the
editorialists' claim that exercise does not lead to weight loss.
What the NIH document actually says -
The magnitude of weight loss due to physical activity is additive to
caloric restriction, but physical activity is generally insufficient by
itself to bring about clinically significant weight loss.
The accompanying figure very clearly demonstrates the degree to which
exercise alone does not result weight loss, and cannot be promoted as a
public health strategy to curb obesity.
This quesiton is in fact the key issue at stake here, whatever one
might think of the other dubious claims ay Malhotra et al.. Data
accumulated since 2008 add further support to that conclusion. Only a
lower intake of calories is effective as a means of weight reduction.
As a co-author of a reference used in the ediorial, which argues that
exercise alone is ineffective, I obviously have some stake in this debate
and would like to see more tranparency on this issue. If there is a
disagreement among observers we should at least be willing use the data
sources correctly. Kelly et al are wrong to claim that -
"All study designs provide clear evidence of a dose-response relation
between physical activity and weight loss."
In the spirit of rigor and honesty I think they should revise their
criticism # 3. Even more importantly, they should provide evidence that
exericse alone prevents or reduces obesity or they should acknowledge - as
the NIH document does - that exercise alone is ineffective.
It seems very clear that there are two different ways of interpreting
the tile of this editorial. BJSM is grateful for the terrific engagement
in this important debate - we revel in debate.
But it's not helpful to have two soliloquys going on so I
respectfully suggest there are two basic interpretations of the title.
Please click through to this Google Community
http://ow.ly/PaHbz
to see the two inte...
It seems very clear that there are two different ways of interpreting
the tile of this editorial. BJSM is grateful for the terrific engagement
in this important debate - we revel in debate.
But it's not helpful to have two soliloquys going on so I
respectfully suggest there are two basic interpretations of the title.
Please click through to this Google Community
http://ow.ly/PaHbz
to see the two interpretations and what may have been a better title (my
fault on the title bit!)...
You'll find more in the 'print' version of BJSM (ie. online in issue
format) from July 17 - the issue of BJSM that puts a spotlight on South
Africa and SASMA (South African Sports Medicine Association).
This article speaks to the growing need to ensure all work groups
including managers take the time to move around more frequently. It is
also interesting to note that while this is based on short term studies it
will have large long term gains. I will be very interested to see where
this research goes in the future. I personally will be looking at ways to
partake of this valuable insight in to the need to move away from...
This article speaks to the growing need to ensure all work groups
including managers take the time to move around more frequently. It is
also interesting to note that while this is based on short term studies it
will have large long term gains. I will be very interested to see where
this research goes in the future. I personally will be looking at ways to
partake of this valuable insight in to the need to move away from my desk.
Since the web site clearly asked for my opinion, I felt I wanted to
share how disappointed I am with this article.
This article looks like it is simply a copy of a systematic review /
metaanalysis published a full 13 months earlier, in september 2013,
meaning that the search was current in March 2012.
The review was criticized at the time of its original publication for
being overly optimistic (see the...
Since the web site clearly asked for my opinion, I felt I wanted to
share how disappointed I am with this article.
This article looks like it is simply a copy of a systematic review /
metaanalysis published a full 13 months earlier, in september 2013,
meaning that the search was current in March 2012.
The review was criticized at the time of its original publication for
being overly optimistic (see the comments on your own web site). That the
data is several years too old, will not help its reliability.
If the review was updated, it could have some additional value over
the original article. However, as it is impossible to tell from the
abstract if any update searches have been implemented, it will be
necessary for me to pay for an article that potentially only contains
outdated, previously published material.
At the age of 86, I am a strong believer in the virtues of moderate physical activity for the elderly, walking some 5 km most mornings, and tending a substantial garden. Moreover, I agree with the proposition that for an elderly population, any physical activity is better than none, and that controlled experiments can be devised to demonstrate some of the short-term benefits of an increase in such activity. However, I w...
It is common practice to refer lower limb injuries as non-contact, in this paper the categories have been clearly defined. The term pressing needs defining which may help the non soccer community. All lower limb injuries in football ought to be categorised as contact or in-direct contact with respect to the ground or an opponent. The principles of the Laws of Motion from Newtonian mechanics and basic physics might add fur...
Testosterone is one of the anabolic androgen steroids (AAS) that has been abused to improve higher athletic performance by enhancing muscle development and recovery. The purpose of this study was to assess basal level of serum total testosterone in male athletes and to compare it with physically active and sedentary males.
The study sample was composed of 40 males divided in four groups of different physical acti...
Recent editorials have renewed the debate on the role of physical inactivity in the current obesity epidemic. [1, 2] Malhotra and colleagues cite an opinion piece suggesting "little change of physical activity levels in the past 30 years," while Blair counters that U.S. Dept. of Labor statistics show "mining, agriculture and agricultural jobs declined substantially."
Both statements have some truth, but they neg...
It is like saying Coca-Cola is the favorite drink of many athletes. The truth is much more complex. Research in this field that is funded by the beverages industry tends to be biased. There will always be people in any field, including scientific research, who will do almost anything to make a buck. I can understand the necessity of balancing the views on any public health issue, but here the balance is tipped over by an ev...
In response to Professor Cooper:
We thank Prof Cooper for his comments (15th June 2015) on our Letter to the Editor, and in particular his critique of our Point 3. We stated in our original letter that "we invite discussion and criticism of our review, and will gladly amend any sections that can...
Kelly et al make a number of useful comments about the unfortunate editirial by Malhotra et al. However they too obscure the main point. They use a 2008 NIH document as the key reference to refute the editorialists' claim that exercise does not lead to weight loss.
What the NIH document actually says -
The magnitude of weight loss due to physical activity is additive to caloric restriction, but physi...
It seems very clear that there are two different ways of interpreting the tile of this editorial. BJSM is grateful for the terrific engagement in this important debate - we revel in debate.
But it's not helpful to have two soliloquys going on so I respectfully suggest there are two basic interpretations of the title.
Please click through to this Google Community http://ow.ly/PaHbz to see the two inte...
This article speaks to the growing need to ensure all work groups including managers take the time to move around more frequently. It is also interesting to note that while this is based on short term studies it will have large long term gains. I will be very interested to see where this research goes in the future. I personally will be looking at ways to partake of this valuable insight in to the need to move away from...
Since the web site clearly asked for my opinion, I felt I wanted to share how disappointed I am with this article.
This article looks like it is simply a copy of a systematic review / metaanalysis published a full 13 months earlier, in september 2013, meaning that the search was current in March 2012.
The review was criticized at the time of its original publication for being overly optimistic (see the...
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