At follow-up , the renal rehabilitation exercise group but not the usual care group showed significant improvements in the 6-minute walk test ( +210.4266.0 ft [ 19 % improvement ] versus -10219.9 ft ; P < 0.001 ) , the sit-to-stand test ( +26.927 % of age prediction [ 29 % improvement ] versus +0.712.1 % of age prediction ; P < 0.001 ) , and the RAND-36 physical measures of role functioning ( P < 0.01 ) , physical functioning ( P < 0.01 ) , energy/fatigue levels ( P = 0.01 ) , and general health ( P = 0.03 ) and mental measure of pain scale ( P = 0.04 ) .