dec/jan 2011 | THE BODY BATTLE special | 39
Research update
The
lapsed
exerciser
If you have a class participant or client who
used to be a regular exerciser, but hasn’t
exercised “for a while”, are they still fit?
Tony Lycholat looks at the research and the
effects of “detraining”.
F
ans of the recent Commonwealth Games in Delhi will be
familiar with the story of successful Australian swimmer
Geoff Huegill. After the Olympic Games in 2004, Huegill
took something of a break from the sport (to put it mildly)
and ballooned up to a formidable 138kg. With his passion and
enthusiasm for elite swimming reignited, Huegill then successfully
lost 49kg (over a two-year timespan) in order to compete in Delhi.
This is an extreme example of someone who gained back their
fitness after time out. What about the average exerciser?
Fortunately, the answers to this type of question have been
provided by an increasing number of training studies that have
looked at what is called “detraining” by exercise scientists. For
example, in what is often now regarded as a classic study by Bengt
Saltin in which he looked at the effects of 20 days of bed rest on five
subjects, the decline in maximum oxygen uptake was 25%. This
decrease in aerobic capacity was accompanied by a decline in the
maximal stroke volume (the amount of blood ejected from the left
ventricle of the heart with each beat) and also, not surprisingly, in
cardiac output.1, 2
Use it or lose it
When the various studies are summarised, it becomes quite clear
that detraining occurs relatively quickly. According to McArdle, Katch
and Katch, “after only one or two weeks of detraining, significant
reductions in both metabolic and exercise capacity can result, and
many of the training improvements are lost in several months”.3
To emphasise the point, McArdle, Katch and Katch kindly provide an
extensive table that charts the decline in a number of “fitness”
variables, both in the short (three weeks or fewer) and long term
(three to 12 weeks). A selection of these variables, their percentage
change and the time course associated with this change is included
in the table below. Note that the figures are from a summary of
published studies.
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Decline in physiological parameters
with detraining
Variable
VO2max
%
change
(short
term)
-8
Capillary density
-7
Cardiac output
-8
Stroke volume
Oxidative enzyme
Capacity
Lactate threshold
- 10
- 29
-7
% change
(long term)
- 18
- 32
- 18
NB: The missing gaps relate to measurements not having been made
Clearly, for the sports performer, these physiological
changes matter hugely and hence explain why time
lost through injury or illness can be critical when it
comes to success at the highest level. Having said
that, virtually all elite sports men and women will have
a brief period of recovery (two to four weeks) at the
end of each competitive year in order to recharge their
batteries (physically, mentally and emotionally) before
the yearly cycle (itself part of a four-yearly Olympic
cycle) starts again.
To view the references related to this article, visit www.fitpro.com/references
Health risk reversal?
Yet, for the born-again recreational exerciser, the bigger
challenge is perhaps less about physiological changes,
such as those listed above, and more to do with
questioning whether the extra weight (as with Geoff
Huegill) they may have put on can now be shifted
successfully, and whether the effects of less than healthy
lifestyle behaviours (over time) may have now lead to
raised cholesterol levels, borderline or mild hypertension
and an increased health risk generally.
The good news is that many adverse adaptations
to relative inactivity are reversible and that lowering
one’s overall health risk is not only possible but
also simple and straightforward, whatever your
current condition or age.
Dealing first with aerobic fitness, it is once
more worth quoting McArdle, Katch and Katch
who argue that, “adaptations in aerobic fitness
occur rapidly and significant improvements are
often noted within several weeks … training
After only one or two
weeks of detraining,
significant reductions
in both metabolic and
exercise capacity can
result
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If an appropriate intervention,
such as physical activity or diet, is
introduced, many epidemiology
studies of 8-12 weeks still show
significant improvements in health
parameters
improvements in previously sedentary people occur
rapidly and continue in a relatively steady fashion”.4
Of course, this pre-supposes a sensible and
progressive training programme is followed and that
everyone realises that there is a genetically
determined fitness ceiling that each individual
approaches with time.
In terms of health, the physical activity
interventions that make the biggest difference to one’s
health risk are well understood and the recently revised
physical activity and public health guidelines from the
American College of Sports Medicine provide not just the
recommendations but the detailed rationale and the
research underpinning this rationale. Of note is the fact
that many (not all) epidemiology studies are relatively
short (e.g., 8-12 weeks in duration) yet still show
measurable and significant improvements in health
parameters, if an appropriate intervention, such as
physical activity or diet is introduced. Those fitness
professionals who wish to skip the detail and go straight to
the guidelines (as if they didn’t know them already) should
perhaps go to the ACSM’s webpage and search for
“physical activity and public health guidelines” so they can
see the synopsis, namely:
Do moderately intense cardio 30 minutes a day, five days
a week
OR
Do vigorously intense cardio 20 minutes a day, three
days a week
AND
Do eight to 10 strength-training exercises, eight to 12
repetitions of each exercise twice a week.5
It really is that simple and, depending upon your starting
point and the parameter you are measuring, expect to
be able to measure real improvement in as few as four to
six weeks for cardiovascular fitness and strength, for
example.
Weight loss
Now, your clients may not lose any excess weight they
have gained like this (or not as quickly as they would like)
but, these days, there are just too many resources –
many of them free – available to help both you and them.
For example, there’s some eminently sensible
advice for health professionals at:
www.nationalobesityforum.org.uk where it is made
clear that “weight reductions of 5-10% of bodyweight
have been shown to improve back and joint pain,
symptoms of breathlessness and sleep apnoea.
Marked improvements in blood pressure and other
risk factors for coronary heart disease have also been
observed in individuals successful at losing weight.” 6
And, let’s be honest, such goals are possible in the
space of three or four months.
Blood lipids and mild hypertension
Further sound advice on modifying blood lipid profile
through exercise and diet is again available from the
ACSM7 and it is hard to find a more well-researched
approach to blood pressure modification than that
presented in the Dietary Approaches to Stop
Hypertension plan.8
The ageing exerciser
Of course, the older lapsed exerciser possibly has a
stronger case for complaining that it becomes increasingly
more difficult to lose weight with advancing years and there
may be some hormonal truth in this (for both men and
women).
However, it is also clear that lifestyle choices that lead
to a reduction in regular planned physical activity, or in
activities of daily living generally, can accelerate the loss
of muscle mass typically associated with getting older,
just as the opposite is also true, with older regular
exercisers maintaining muscle mass.
Furthermore, it would appear that any woman wishing
to blame the menopause is now on thin ice. According to
Dr Barbara Bushman, “Menopause is a time often
associated with undesirable increases in bodyweight
and increases in body fat while lean mass decreases.
Whether these changes are a result of menopause
specifically or ageing in general may be debated by
some. Regardless, it seems that lifestyle modifications,
including a focus on dietary factors and physical activity
can help … is weight gain at menopause inevitable? The
answer is no.” 9
Summary
If you haven’t exercised for a few weeks, you will
notice a decline in fitness but probably not in your
general health risk; going back to a planned and
progressive exercise programme that takes your current
fitness level as the starting point will have you back up to
speed, probably in six to 12 weeks. Achieving your
desirable bodyweight and body composition (following a
lapse) in a healthy manner may take longer, depending
upon your starting point.
If you have been physically inactive for six months or
more, then you are effectively starting from scratch.
The good news is that you can regain your fitness and
lower your cardiovascular health risk – whatever your
age – with significant results in both fitness parameters
and cardiovascular health risk being possible in as
few as three months. fp
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