We previously reported that exercise suppresses the intrarenal renin-angiotensin system and improves nocturnal polyuria in aged mice (1). Based on this translational background, we aimed to investigate whether exercise therapy is effective for nocturnal polyuria in older adults with nocturia. We also examined which changes in physical activity were associated with improvement in nocturnal polyuria.

This was a prospective clinical study. Fifteen older men receiving outpatient care for nocturia were enrolled. The median age was 80 years. Participants were observed during a 1-month baseline period with their usual lifestyle, followed by a 3-month intervention period during which they were instructed to increase daily physical activity with emphasis on regular exercise. Physical activity was assessed using a wearable device (HJA-750C Active style Pro®), which recorded daily step count, energy expenditure, and duration of physical activity according to intensity during the most recent month of each study period. Voiding diary data were used to evaluate daytime and nocturnal urine volume, daytime and nocturnal voiding frequency, and voided volume per void. Changes before and after exercise promotion were compared, and factors associated with reduction in nocturnal polyuria index were analyzed.

After exercise promotion, daily step count significantly increased from 6021±1133 to 7363±931 steps/day (p=0.043) (Fig. 1A). Moderate-intensity physical activity increased from 69±11 to 77±11 minutes/day (Fig. 1B), although this did not reach statistical significance (p=0.097). Total energy expenditure and low-intensity physical activity were not significantly changed. Daytime urine volume increased from 1109±131 to 1395±168 mL (p<0.01). Nocturnal urine volume changed from 732±72 to 600±48 mL (p=0.071), and nocturnal polyuria index significantly decreased from 40.7±2.8% to 32.0±3.3% (p=0.019) (Fig. 1C). Nocturnal voiding frequency significantly decreased from 4.1±0.4 to 2.4±0.3 (p=0.003) (Fig. 1D), while nocturnal voided volume per void increased from 197±14 to 263±26 mL (p=0.013). Increase in step count (p=0.049) and increase in moderate-intensity physical activity time (p=0.044) were significantly associated with reduction in nocturnal polyuria index.

These findings suggest that increasing daily physical activity, particularly step count and moderate-intensity exercise, may improve nocturnal polyuria in older adults. The increase in daytime urine output together with reduction in nocturnal polyuria index may indicate a redistribution of urine production from night to day. This pattern is clinically meaningful because it was accompanied by a reduction in nocturnal voiding episodes.

Exercise therapy, especially increased walking and moderate-intensity physical activity, may be an effective non-pharmacological treatment option for nocturnal polyuria in older adults with nocturia.

(1)	Imanaka T, Takezawa K, Kujime Y, Kitakaze H, Tsujimura G, Kuribayashi S, Sekii Y, Ueda N, Fukuhara S, Kiuchi H, Negoro H, Nonomura N. Decreased nitric oxide production is a novel therapeutic target for salt-induced nocturnal polyuria in aging. Sci Rep. 2025 Jan 28;15(1):3589.