Effects of Home-Based Interval Walking Training on Thigh Muscle Strength and Aerobic Capacity in Female Total Hip Arthroplasty Patients: A Randomized, Controlled Pilot Study

Due to the reduced physical activity of patients who have undergone total hip arthroplasty (THA), there are no home-based exercise training regimens for preventing muscle atrophy and aerobic capacity impairment in these patients. We examined whether interval walking training (IWT) could prevented these issues. Twenty-eight female patients (∼60 years of age) who had undergone THA more than 2 months prior were randomly divided into IWT (n = 14) and control (CNT, n = 14) groups. The IWT subjects trained at a target of 60 min of fast walking at >70% peak aerobic capacity for walking ( O 2peak ) per wk for 12 wk, while those in the CNT maintained their previous sedentary life during the same period. We measured the energy expenditure of the daily physical activity, except during sleeping and bathing, every minute and every day during the intervention. We also measured the isometric knee extension (F EXT ) and flexion (F FLX ) forces,O 2peak , and anaerobic threshold during the graded cycling exercise ( O 2AT ) before and after the intervention. All subjects, except for one in IWT, completed the protocol. F FLX increased by 23% on the operated side ( P  = 0.003) and 14% on the non-operated side of IWT ( P  = 0.006), while it only increased on the operated side of CNT ( P  = 0.03). TheO 2peak andO 2AT in IWT increased by 8% ( P  = 0.08) and 13% ( P  = 0.002), respectively, and these changes were significantly higher in the IWT than in CNT group (both, P <0.05). In conclusion, IWT might be an effective home-based training regimen for preventing the muscle atrophy from reduced daily physical activity in THA patients. Trial Registration UMIN-CTR UMIN000013172