Many people make a new year's resolution to lose those unwanted, extra Christmas pounds by reducing how much they eat and increasing the amount of exercise they do.
Scientists at the University of Bath have examined how long people should exercise for and with what intensity.
people blame lack of time for not exercising, and others opt for
briefer, more intensive sessions in the gym to make all their
commitments fit into busy schedules.
The scientists discovered that more demanding
exercise does not in itself bring health benefits that people cannot get
from longer but more moderate activity - exercise that may be more
suitable for people who have traditionally been less active.
the overall number of calories burned over a day or a week does not
differ, people who have gone for what may seem like the easier option
may do just as well in shedding fat and improving their health.
part of the study, 38 sedentary and overweight men and post-menopausal
women with an average age of 52 were asked to exercise five times per
week and cut the number of calories consumed through food and drink.
Half the participants exercised vigorously on a treadmill, whilst the other half at moderate-intensity.
and after the three-week monitoring period, participants had blood
insulin measured and biopsies of fat tissue taken, with surprising
Both groups lost the same amount of weight and
improvements in insulin sensitivity and metabolic health were detected
in both groups - with a similar reduction in fat mass, blood pressure,
cholesterol and a range of other measures.
changes in the activation of genes within fat cells in both groups were
also found, highlighting benefits within the fat tissue itself.
The vast majority of these changes were unaffected by the intensity of the exercise.
Dylan Thompson, from the university's Department for Health, said: "A
critical feature of our experiment was that we carefully matched the
groups, so all participants expanded the same calories during each
exercise session and experienced the same calorie reduction by consuming
"If you want to increase the amount of
exercise you do as a new year's resolution, then our study shows that
benefits are similar whether you choose to exercise for longer at a
lower intensity, or for less time but more vigorously."
According to Dr James Betts, another of the
researchers, few studies until theirs had looked into what was actually
happening within the tissue that responds most to weight loss, like fat.
we investigated the whole body or certain molecules within the fat
tissue, the benefits from increased exercise and a reduction in dietary
intake were evident, but mostly independent of the intensity of the
exercise," he said.
report's lead author, Dr Jean-Philippe Walhin, said: "Three weeks of
increased exercise combined with a reduction in dietary intake had a
dramatic impact on the overall health of the participants and on key
genes within their fat tissue.
"However, our data
demonstrates that what really matters is how many calories were used up
by exercising in total, not so much the intensity of the exercise
:: The study, The impact of exercise
intensity on whole body and adipose tissue metabolism during energy
restriction in sedentary overweight men and postmenopausal women, is
published in the journal Physiological Reports.