Exercise in cold water may increase appetite, UF study finds

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Exercise in cold water may increase appetite, UF study finds

05 May 2005 Medical News Today

Exercise in cold water instead of warm water may increase people's

appetites, making it harder for them to lose extra pounds, a

University of Florida study finds.

Results indicate people may consume more calories after exercising in

cold water, according to Lesley White, a UF researcher who designed

the study to better understand why aquatic exercise is often less

successful than equal amounts of jogging or cycling for people who

want to lose weight.

" It's possible that individuals who exercise in cooler water may have

an exaggerated energy intake following exercise, which may be a

reason why they don't lose as much weight, " said White, an assistant

professor in the College of Health and Human Performance. " So it may

not be the exercise itself that causes the problem because you can

match the exercise energy expenditure; rather it's the increased

eating after the exercise is over. "

White said her research is not meant to suggest that swimming or

aquatic exercise is ineffective for building physical fitness. In

fact, water exercise is suggested for people who are overweight

because the buoyancy given by the water makes exercising easier for

people with joint or balance problems.

" Water exercise is an excellent activity for many people,

particularly those with joint disorders, thermal regulatory problems

and balance or coordination difficulties, " she said. " However, an

earlier study reported that women who swam did not lose as much

weight as those who jogged or cycled. "

For her study, published in February in the International Journal of

Sport Nutrition and Exercise Metabolism, White tracked the energy

used by 11 UF students as they rode a stationary bicycle submerged in

water for 45 minutes. The students exercised in cold water of 68

degrees Fahrenheit and warm water of 91.4 degrees Fahrenheit. The

same students, ages 21 to 31, also spent 45 minutes resting. The

study found the students used a similar amount of energy during the

exercises, 517 calories in the cold water and 505 in the warm water.

Students expended 123 calories while resting.

After each exercise session and the rest period, the students were

allowed into a room to measure their blood pressure and heart rates.

They were left to rest for one hour in the same room and had free

access to a standard assortment of food of known caloric values.

However, the students didn't know their caloric intake was going to

be measured.

" We found that during the recovery period when the subjects had

access to an assortment of foods that significantly more calories

were eaten after exercise in cold water compared to exercise in warm

water or at rest, " White said.

Caloric intake after exercise in cold water was 44 percent higher

than exercise in warm water and 41 percent higher than in the resting

periods. The students consumed a mean 877 calories after exercise in

cold water, 608 calories after exercise in warm water and 618 after

resting periods.

" This is a preliminary study, which suggests that environmental

conditions during exercise may influence post-exercise appetite, "

White said. Individuals should consider the kinds of foods they eat

after exercise, she added.

White suggested that body temperature might have some influence over

post-exercise appetite.

A previous study by her colleague Dr. Rudolph Dressendorfer indicated

that body temperature at the end of exercise can affect post-exercise

appetite.

" Aquatic exercise is widely used in weight-loss programs, especially

for those people with orthopedic concerns, " said Dressendorfer, an

adjunct professor with the faculty of physical education and

recreation at the University of Alberta and a physical

therapist. " The practical implication of this study is that cold

water temperature could frustrate weight loss by increasing caloric

intake. This study also provides some theoretical insight to the

mechanism of appetite after exercise. "

http://www.ufl.edu