Comparative Effects Of Aerobic, Resistance, Or Combined Exercise On Body Shape

PURPOSE: While exercise is known to produce anthropometric changes, few studies have examined the comparative effectiveness of different types of exercise training on body shape. This study examined body shape changes in response to 6 months of aerobic (AE), resistance (RE), or combined aerobic and resistance exercise (CE). METHODS: Participants were 60 inactive adults (54% women, 35-69 years) with overweight/obesity. Participants were randomized to AE only (n = 17), RE only (n = 17), CE (n = 16), or a no-exercise control (CON; n = 10) group for 6 months. Exercise was performed three times a week for 60 minutes (for CE, AE and RE were both performed for 30 minutes) at 50-80% of their maximum intensity. To assess body shape, participants wore tight fitting clothing, and a camera captured visual data through 360 degrees to generate a 3D avatar. The 3D scanner produced an index score (range 0-100), termed the Body Shape Rating (BSR) based on whole body anthropometric measures (e.g., BMI, waist circumference) with higher scores indicating higher body density and lower body volume (e.g., lower waist circumference). Participants exhibiting increased BSR from baseline to 6 months were categorized as having improved BSR, and group differences were evaluated with chi square tests. BSR change scores were then compared between exercise groups with one-way analysis of variance (ANOVA). Tukey’s post hoc tests were performed for pairwise comparisons. RESULTS: There were no differences in BSR between groups at baseline (p = 0.44). BSR improved in 59% of AE, 71% RE, 75% of CE, and 2% of CON participants, with significant between group differences (p = 0.03). There were group differences in BSR change scores (p = 0.004) with significant differences between AE and CON (mean difference [MD] = 15.19, p = 0.005), and CE and CON (MD = 11.73, p = 0.047). Despite a lack of statistical significance between RE and CON (p = 0.07), the MD (10.78) was similar to that of CE and CON, and not significantly different between RE and AE (p = 0.64), RE and CE (p = 0.99), and AE and CE (p = 0.80). CONCLUSION: This study indicates that all types of exercise improved body shape in the majority of participants (60-75%). AE provided the greatest magnitudes of body shape improvement but in fewer participants, while CE and RE lead to more consistent, albeit smaller, improvements. NIH Grant R01HL133069