Effects of high intensity resistance aquatic training on body composition and walking speed in women with mild knee osteoarthritis: a 4-month RCT with 12-month follow-up.

Abstract

To investigate the effects of 4-months intensive aquatic resistance training on body composition and walking speed in post-menopausal women with mild knee osteoarthritis (OA), immediately after intervention and after 12-months follow-up. Additionally, influence of leisure time physical activity (LTPA) will be investigated. This randomised clinical trial assigned eighty-seven volunteer postmenopausal women into two study arms. The intervention group (n=43) participated in 48 supervised intensive aquatic resistance training sessions over 4-months while the control group (n=44) maintained normal physical activity. Eighty four participants continued into the 12-months' follow-up period. Body composition was measured with dual-energy X-ray absorptiometry (DXA). Walking speed over 2km and the knee injury and osteoarthritis outcome score (KOOS) were measured. LTPA was recorded with self-reported diaries. After the 4-month intervention there was a significant decrease (P=0.002) in fat mass (mean change:-1.17kg; 95% CI:-2.00 to-0.43) and increase (P=0.002) in walking speed (0.052m/s; 95% CI: 0.018 to 0.086) in favour of the intervention group. Body composition returned to baseline after 12-months. In contrast, increased walking speed was maintained (0.046m/s; 95% CI 0.006 to 0.086, P=0.032). No change was seen in lean mass or KOOS. Daily LTPA over the 16-months had a significant effect (P=0.007) on fat mass loss (f2=0.05) but no effect on walking speed. Our findings show that high intensity aquatic resistance training decreases fat mass and improves walking speed in post-menopausal women with mild knee OA. Only improvements in walking speed were maintained at 12-months follow-up. Higher levels of LTPA were associated with fat mass loss. ISRCTN65346593.