Exercise Patterns And Body Composition Among Resistance Trained And Non-Resistance Trained Younger And Older Adults

With aging, percent body fat (%BF) tends to increase and muscle mass decreases, which may limit ability to engage in higher intensity exercise. Exercise has been shown to improve body composition, but it is unclear if patterns of exercise (duration, intensity) are impacted by resistance training (RT) in younger and older adults. PURPOSE: To determine if resistance trained and untrained younger and older adults differ on duration of high, moderate, and low intensity exercise and %BF. METHODS: Younger (23.8 ± 0.4 years) and older (68.5 ± 1.2 years) healthy adults were categorized into 4 groups based on RT status: Young RT (YT: n = 22), Young Not RT (YNT: n = 16), Old RT (OT: n = 17), and Old Not RT (ONT: n = 20). RT participants trained ≥2X per week, for the past ≥6 months. Subjects completed a survey to assess exercise intensity and duration, and dual x-ray absorptiometry (DXA) to determine %BF. The survey assessed total time per week participants engaged in high, moderate and low intensity exercise. Responses were coded as 1 = none, 2 = 30-60 minutes, 3 = 1-2 hours, 4 = 2-3 hours, 5 = 3-5 hours, 6 = > 5 hours. ANOVAs determined group differences, p ≤ 0.05. Data are reported as mean ± SE. RESULTS: Group differences emerged for high and moderate (p < 0.05), but not for low intensity exercise (p > 0.05). For high intensity, YT (3.64 ± 0.31) was higher than YNT and ONT (YNT: 1.63 ± 0.37, p < 0.001; ONT: 1.55 ± 0.33, p < 0.001), and OT (2.82 ± 0.36) was higher than YNT (p = 0.022) and ONT (p = 0.010). For moderate intensity, YT (4.91 ± 0.31) was higher than YNT and ONT (YNT: 2.40 ± 0.38, p < 0.001; ONT: 3.52 ± 0.32, p = 0.003), OT (4.77 ± 0.35) was greater than YNT (p < 0.001) and ONT (p = 0.011), and ONT was greater than YNT (p = 0.025). For %BF, YT (25.06 ± 2.1%) was lower than YNT and ONT (YNT: 33.55 ± 1.87%, p = 0.001; ONT: 36.47 ± 1.28%, p < 0.001), and OT (29.37 ± 1.11%) was lower than ONT (p = 0.003). CONCLUSIONS: Younger and older resistance trained groups did not differ on exercise patterns or %BF, suggesting the enduring positive effects of resistance training as individuals age. Resistance trained individuals performed more moderate and high intensity exercise than non-resistance trained, likely contributing to favorable body composition.