A pilot study of twice-weekly exercise during hemodialysis in children

Few published studies have assessed the exercise capacity and/or the effect of exercise in children receiving maintenance hemodialysis (HD). The aim of this study was to determine if twice-weekly exercise for 1 h during HD could improve exercise capacity in children receiving HD. We assessed lower extremity strength (Biodex; dominant extension peak torque in 60 degrees per second, Newton-meters), grip strength (dynanometer, kilogram) and 6-min walk capacity (yards) in ten children (median age 13.6 years, range 8-25 years) at baseline and after 3 months of twice weekly exercise for 1 h during HD. Baseline assessment revealed a mean (1) Biodex of 70 +/- 32 N-m/s, (2) 6-m walk test of 589 +/- 90 yards and (3) grip strength of 23.2 +/- 10 kg, which were 50% lower than the normal value for healthy controls. Patients demonstrated significant improvements in lower extremity strength and 6-min walk test after 3 months of exercise. Our data show that twice-weekly exercise of a moderate intensity during HD can lead to exercise capacity improvement in 3 months. We identified barriers to and strategies for the successful implementation of intradialytic exercise. We suggest that intradialytic exercise intervention may be effective to improve exercise capacity in children receiving maintenance HD.