Bonnie Bruce ^1*, James F. Fries ¹, Helen Hubert ¹

¹ Stanford University

^* To whom correspondence should be addressed. E-mail: bbruce{at}stanford.edu.

	Abstract

Objectives. We examined the relationship of regular exercise and body weight to disability among healthy seniors.

Methods. We assessed body mass index (BMI) and vigorous exercise yearly (1989–2002) in 805 participants aged 50 to 72 years at enrollment. We studied 4 groups: normal-weight active (BMI<25 kg/m2; exercise>60 min/wk); normal-weight inactive (exercise60 min/wk); overweight active (BMI25 kg/m2); and overweight inactive. Disability was measured with the Health Assessment Questionnaire (0–3; 0=no difficulty, 3=unable to do). We used multivariable analysis of covariance to determine group differences in disability scores after adjustment for determinants of disability.

Results. The cohort was 72% men and 96% White, with a mean age of 65.2 years. After 13 years, overweight active participants had significantly less disability than did overweight inactive (0.14 vs 0.19; P=.001) and normal-weight inactive (0.22; P=.03) participants. Similar differences were found between normal-weight active (0.11) and normal-weight inactive participants (P<.001).

Conclusions. Being physically active mitigated development of disability in these seniors, largely independent of BMI. Public health efforts that promote physically active lifestyles among seniors may be more successful than those that emphasize body weight in the prevention of functional decline.

Key Words: Aging, Disability, Exercise/Physical Activity, Obesity, Overweight, Underweight