Looking to lose weight and fat in the new year? Aerobic exercise may be your best bet.
Aerobic exercise -- which includes sweat-inducing activities like
walking, running and swimming -- has been known to help people reach
their target weight. However, resistance training, which includes weight
lifting to build muscle mass, is normally more advised because it has
the ability to raise a person's resting metabolic rate -- the amount of
calories you burn while resting -- and improve glucose control. But,
resistance training's effects on fat loss have not been proven.
"Balancing
time commitments against health benefits, our study suggests that
aerobic exercise is the best option for reducing fat mass and body
mass," Cris A. Slentz, a Duke exercise physiologist, said in a press release."It's not that resistance training isn't good for you; it's just not very good at burning fat."
For
the study, researchers looked at 234 overweight or obese people.
Subjects either had to do resistance training (three sets of weight
lifting for three days a week, eight to 12 repetitions per set), aerobic
training (about 12 miles a week) or aerobic and resistance training
(both requirements). Exercise sessions were supervised to make sure
everyone was doing what they were supposed to.
Researchers then used data from 119 people who successfully completed the exercise regimen.
The
aerobic exercise group worked out an average of 133 minutes a week and
lost weight, while the resistance group worked out about 180 minutes a
week without dropping pounds.
The combination group,
while having to spend twice the amount of time to complete both
routines, had a mixed result. They did not lose weight and fat mass, but
they did have the biggest reduction in waist circumference probably due
to the time they spent working out.
Resting metabolic
rate was not measured. But, since the scientists observed no changes in
weight or fat loss, the common assumption that resistance training may
increase the resting metabolic rate may be moot.
"No one
type of exercise will be best for every health benefit," author Leslie
H. Willis, MS, an exercise physiologist at Duke Medicine, said in a
press release. "However, it might be time to reconsider the conventional
wisdom that resistance training alone can induce changes in body mass
or fat mass due to an increase in metabolism, as our study found no
change."
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However, Dr. Timothy Church, director of preventive medicine
research at Pennington Biomedical Research Center in Baton Rouge, La.,
cautioned to HealthDay
that resistance training shouldn't be discounted because people lose
muscle mass when they grow older, and stronger muscles can help improve
quality of life.
Dr. Melina Jampolis, a physician nutrition specialist and CNN's diet and fitness expert, also warned to CNN that we don't know how effective aerobic exercise is at weight loss in the long run.
"If
you are short on time and are not dieting, cardio is better for weight
loss in the short-term, but we don't know in the long-term. And in my
opinion, to maintain weight loss and achieve optimal health, strength
training is still very important," said Jampolis.
The study appeared Dec. 15 in the Journal of Applied Physiology.
