Weight Loss and Physical Activity Reduces Perceived Physical Fatigability Among Older Adults With Obesity.

OBJECTIVE: This study aimed to evaluate the impact of three lifestyle interventions on perceived physical fatigability. METHODS: Concurrent with a dietary weight loss program (caloric deficit ~400 kcal/day, weekly dietitian support), older adults with obesity (N = 183) were randomized to three groups: aerobic exercise (150-200 min/week of moderate-intensity treadmill walking; n = 60), daylong movement (improving daily activity distribution, progressively increase steps/day; n = 63), or combination (aerobic and daylong movement interventions; n = 60). Perceived physical fatigability (Pittsburgh Fatigability Scale [PFS] Physical score, range 0-50, and Rating of Perceived Exertion [RPE] after a 5-min 0% grade treadmill walk, range 6-20; higher = greater fatigability) was measured at baseline, 6 months (post-intensive intervention), and 18 months (end of maintenance period). RESULTS: Participants (69.6 ± 4.3 years, 77% female, 74% White, 35.6 ± 3.8 kg/m2 BMI) had a PFS Physical score 20.6 ± 7.6 and RPE Fatigability 9.6 ± 1.9 at baseline. Clinically relevant improvements were observed in PFS score from baseline to 6 months (-4.4 points, p = 0.002) and were largely maintained at 18 months (-3.0 points, p = 0.03) after adjustment for baseline age, sex, education, intervention group, and time × intervention group (p = 0.83). RPE Fatigability did not improve (p > 0.05). CONCLUSIONS: Multiple physical activity strategies in conjunction with weight loss improved perceived physical fatigability over time among older adults with obesity. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02923674.