workouts may curb people's appetite shortly afterward, according to a small study.
The researchers found that overweight men ate about 200 fewer calories
following a vigorous workout than after rest.
Some studies have shown that high intensity exercise is tied
to appetite suppression and changes in hormones that regulate hunger and
fullness, and the new research found different effects on those hormones among
the various exercise regimens.
In the latest research, published in the International
Journal of Obesity by Aaron Sim, a graduate student at the University of
Western Australia, and his colleagues, 17 overweight men volunteered to
participate in four 30-minute exercise sessions: one in which they only rested
and three involving stationary cycling at either moderate, high or very high
The moderate exercise involved continuous cycling, while the
more intense workouts alternated between short bursts of speed and longer
stretches of pedalling at a lower speed. After each session the men drank a
liquid meal of about 267 calories. Then, a little over an hour later, the
researchers offered the participants oatmeal and told them to eat until they
were "comfortably full". The men ate fewer calories after the high and
very high intensity workouts compared to the times when they rested.
They also ate less after the very high intensity workout
than after the moderate exercise, while the difference between the high
intensity workout and the moderate workout was small enough that it could have
occurred by chance. After the sessions, the men ate 764 calories after resting,
710 calories after the moderate exercise and 621 calories after the high
intensity workout and 594 calories after the very high intensity workout.
The following day
The men also reported eating fewer calories on the day
following the highest intensity workout than they did on the days following the
other exercise sessions. They ate 2 000 calories during the day following the
very high intensity workout, while they ate a little more than 2 300 calories
during the day after the moderate exercise and more than 2 600 during the day
following the resting session.
While the study shows promising
cuts in calorie intake in the short-term, it's unclear whether high intensity
exercise can affect longer term weight loss. David Stensel, a researcher at
Loughborough University in the UK who has studied exercise's effect on food
intake, cautioned that this was a small study that needs to be repeated before
any conclusions can be drawn. Other studies, including Stensel's, have not
shown a difference in how much people eat following a period of exercise or of
rest, he said.
Stensel said the findings were somewhat surprising, because
his own research has not shown that people's food intake is reduced following
exercise."One thing that's different is they've done this in an overweight
or obese population. Most of the research that's been done is in normal weight
or healthy weight individuals," Stensel told Reuters Health."This
study provides some promising preliminary support for this notion, but further
research is needed to investigate this in a longer-term study," Sim said.