At follow-up , the renal rehabilitation exercise group but not the usual care group showed significant improvements in the @-minute walk test ( +@ ft -LSB- @ % improvement -RSB- versus -@ ft ; P < @ ) , the sit-to-stand test ( +@ % of age prediction -LSB- @ % improvement -RSB- versus +@ % of age prediction ; P < @ ) , and the RAND-@ physical measures of role functioning ( P < @ ) , physical functioning ( P < @ ) , energy/fatigue levels ( P = @ ) , and general health ( P = @ ) and mental measure of pain scale ( P = @ ) .