Statement of the problem: Generalized Anxiety Disorder (GAD) and disturbed sleep are prevalent, debilitating, and frequently comorbid problems for which successful treatment remains limited. Exercise can promote sleep but whether it does among GAD patients is unknown.

Methods: Thirty sedentary women (18-37y) with a primary DSM-IV diagnosis of GAD were randomized to six weeks of resistance (RET) or aerobic exercise training (AET), or waitlist (WL). RET and AET involved twice-weekly sessions of either lower-body weightlifting or leg cycling matched on multiple features of exercise. Outcomes included total sleep time (TST), lights out time, awakening out of bed time, time in bed (TIB), sleep onset latency (SOL), wakefulness after sleep onset, and sleep efficiency. Hedges' d effect sizes and 95% confidence intervals were calculated for each exercise condition compared to WL. Regression examined baseline associations between anxiety and sleep and associated change.

Results: Twenty-two of 26 participants reported poor baseline sleep (Pittsburgh Sleep Quality Index >5). RET significantly decreased weekend TIB (d=-1.79; [-2.89, -0.70]) and SOL (d=-1.30; [-2.32, -0.28]), and significantly increased weekend sleep efficiency (d=1.30; [0.29,2.32]). AET significantly reduced weekend TIB (d=-1.13; [-2.16, -0.11]) and SOL (d=-1.08; [-2.09, -0.06]). Reduced GAD clinical severity rating was significantly associated with improved weekend sleep efficiency among RET (t₆=-3.48, p≤0.013).

Conclusions: Short-term exercise training improves sleep outcomes among GAD patients, especially for RET and weekend sleep. Findings suggest improved sleep may be associated with reduced clinical severity among GAD patients.