A prospective study of physical activity intensity and change in adiposity in middle-aged women.

PURPOSE

To determine the extent to which objectively measured intensity of physical activity (PA) predicts change in body fat (BF%) in women.

DESIGN

Prospective cohort study of PA intensity and body composition in middle-aged women.

SETTING

The study took place in a metropolitan Mountain West community.

SUBJECTS

Two hundred and twenty-eight women participated in two assessment periods separated by 20 months.

MEASURES

Each assessment period consisted of seven consecutive days of monitoring, followed by body composition testing.

ANALYSIS

The general linear model using partial correlations and Mantel-Haenszel chi2 tests were performed.

RESULTS

At baseline and follow-up, women who participated in vigorous PA were leaner than women who participated in moderate or light PA (p < .05). Longitudinal results indicated that a greater proportion of women who decreased PA intensity over the 20 months also increased BF% (66%), compared to participants who increased or maintained PA intensity (47%) (p < .05).

CONCLUSIONS

PA intensity seems to play a role in long-term weight maintenance. Reducing PA intensity increases the risk of BF% gain in women. Efforts to help women maintain PA intensity along with other weight management strategies may prove beneficial in preventing unwanted body fat gain in middle-aged women.