Exercise 'may benefit some less'
http://news.bbc.co.uk/1/hi/health/4059695.stm
There may be an explanation for why
those gym workouts seem not to
have any effect - US experts suggest
some people benefit less from
exercise.
Louisiana University researchers put
742 people through a strenuous
20-week endurance training
programme.
Measures such as oxygen
consumption improved in some, but not in others, New
Scientist magazine
revealed.
UK sports experts said people did differ - and that
was why they should have
tailored exercise programmes.
The researchers selected the
volunteers from 213 families,
None of the participants had
undertaken regular physical activity for
the previous six months.
All were asked to use exercise bikes. By the last six
weeks of the study, they
were exercising for 50 minutes, three times a week,
at 75% of the maximum
output they were capable of before the study.
Differences
Previous research had suggested that people do vary
in their "trainability" -
how much improvement is likely to be seen after an
exercise regime.
In this study, the researchers found training
improved maximum oxygen
consumption, a measure of a person's ability to
perform well, by an average
of 17%.
But the most "trainable" participants improved by 40%
- and the least
showed no improvement at all.
Similar patterns were seen when other fitness
measures such as cardiac
output, blood pressure, heart rate were checked.
When the researchers looked at insulin resistance, a
marker of risk for heart
disease and diabetes, they found it had improved in
58% of participants
following the exercise regime but stayed the same, or
even fell, in 42%.
The team also compared the eight who showed the
highest improvement in
insulin sensitivity and the eight who had least.
The study was presented to the Australian Health and
Medical Research
Congress in Sydney.
Claude Bouchard, who led the research, said: "There
is an astounding
variation in the response to exercise.
"The vast majority will benefit in some way, but
there will be a minority who
will not benefit at all."
Kathryn North of the Institute of Neuromuscular
Research at the Children's
Hospital at Westmead, Sydney, said: "It's negative,
but it's true. Some people
slog away and don't get any improvement."
Mark Hargreaves, of Deakin University, Melbourne,
added: "We need to
recognise that, although on average exercise may have
clear benefits, it may
not work for everyone.
"Some people may do better to change their diet."
But Sam Howells, senior sports physiologist at
Lilleshall Sports Injury and
Human Performance Centre, said: "It would be worrying
if these findings
deterred people from exercising.
"What this study shows is that everyone is unique.
"That's why fitness programmes should be tailored to
an individual's needs.
"But everyone should do something to try to stay
fit."
Linda Bishop Bailey, of the Institute of Sport and
Recreation Management,
said: "This research will be music to the ears of the
UK's army of couch
potatoes.
She added: "Although this study focuses on the
physical benefits of exercise
we mustn't forget that there are other benefits too.
Fitness is fun and has
psychological benefits such as helping to combat
stress.
"Worryingly at this time of year gyms across the UK
see a lot of people who
have over indulged at Christmas and try to make up
for it by binge-exercising
in the New Year.
"When they don't see immediate results they get
de-motivated and give up."