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

Perceived physical fatigability, whole-body fatigue in the context of activity, is highly prevalent (ranging 30-90%) among older adults, and predicts disability and death. Limited work shows that lifestyle interventions may improve perceived physical fatigability, yet this work is hampered by small sample sizes, conducted in younger populations, and has poorly defined interventions. PURPOSE: We evaluated the impact of weight loss plus two different lifestyle interventions on perceived physical fatigability using data from an 18-month randomized clinical trial in older adults with obesity. METHODS: Concurrent with a dietary weight loss (WL) intervention, older adults with obesity (N = 183) were randomized to three groups: aerobic exercise (WL + EX, n = 60), daylong movement (WL + DLM, n = 63), or exercise plus daylong movement (WL + EX + DLM, n = 60). WL + EX group engaged in regular aerobic treadmill walking with a goal of walking 150 min/wk. The WL + DLM group engaged in a progressive stepping program with a general goal of 10,000 steps/d accrued throughout the day, and WL + EX + DLM engaged in both. The intervention was 6 mo, followed by a 12-mo maintenance period. Perceived physical fatigability (Pittsburgh Fatigability Scale [PFS] Physical score, range 0-50, higher = greater fatigability) was self-administered at baseline, 6 mo, and 18 mo. RESULTS: Participants (69.6 ± 4.3 years, 77% female, 74% white non-Hispanic, 35.6 ± 3.8 kg/m2 body mass index) had a mean PFS Physical score of 20.6 ± 7.6 at baseline (33.3% classified in most severe PFS strata ≥ 25). PFS Physical score significantly improved over time with an average 21% reduction (-4.4 points) from baseline to 6 mo and 14% reduction (-3.0 points) from baseline to 18 mo, after adjustment for baseline age, sex, and education level (both p < 0.0001). PFS Physical score did not differ by intervention groups over time (p = 0.83). CONCLUSION: A weight loss plus lifestyle intervention meaningfully reduced perceived physical fatigability among older adults with obesity. Though future work will disentangle weight loss from physical activity, these findings indicate that interventions focused on increasing aerobic exercise, improving daylong movement, or both, may lead to similar improvements in fatigability and informs future work to prevent or delay age-related disability. Supported by: NIH and National Institute of Aging R01 AG051624