RELATIONSHIPS AMONG BMI, PHYSICAL ACTIVITY, AND REASONS FOR EXERCISE IN MALE AND FEMALE COLLEGE STUDENTS

Abstract

Knowing what motivates individuals to exercise is important in selecting appropriate intervention strategies to increase regular activity. PURPOSE: To assess relationships among body mass index (BMI), reasons for exercise, and exercise patterns. METHODS: Subjects (108 women & 53 men, 18–33 y) were surveyed as a part of an extra credit opportunity in an introductory psychology class. Students completed the Silberstein Reasons for Exercise Inventory (REI), a physical activity survey (PAS), and a demographic data sheet for determination of age, gender, weight, and height. Seven REI subscales (exercising for weight control, fitness, mood, attractiveness, health, enjoyment and toning) were used. The PAS applied CDC definitions for regular, moderate-intensity, and vigorous-intensity activity in the assessment of exercise 6 months earlier, during the past month, and planned for 6 months in the future. RESULTS: Gender analyses revealed significant differences in REI and BMI but not PAS. Males had significantly higher BMI (25.3 + 5.3 kg/m2) and were more likely to report exercising for enjoyment (4.8 + 1.5) than were females (BMI = 22.2 + 3.4 kg/m2, enjoyment = 4.0 + 1.6; p < .05 for all analyses). Yet, females were more likely to exercise for weight control (5.0 + 1.2) and to improve tone (4.6 + 1.4) than were males (weight control = 3.8 + 1.4; tone = 3.9 + 1.5, p < .05 for all analyses). Given the gender differences, relationships between BMI and REI were determined for males and females separately. While a significant relationship between BMI and exercise for weight control was observed for males (r = .284, p < .05), no significant relationships were observed for females. Overall, a significant inverse relationship was found between BMI and frequency of past (r = −.216), present (r = −.257) and future (r = −.165) moderate intensity activity (p < .05). CONCLUSION: Moderate-intensity activity was related to lower BMI in both sexes, but the sexes differed in motivation to exercise for weight loss and in how that desire related to BMI.