Muscle performance and functional capacity retention in older women after high-speed power training cessation.

Power declines more steeply than strength with advancing age and training cessation among older women and is associated with the loss of functional ability. We tested the hypothesis that the impact of 6 weeks of detraining (DT) subsequent to 12 weeks of high-speed power training on maximal strength (1RM) of the arm and leg muscles, power performance (counter movement jump and ball throwing) and functional task (sit-to-stand test) would decrease physical performance, and specifically power performance. Thirty-seven older women were divided into an experimental group and a control group [EG, n=20, 65.8 (2.5) years; CG: n=17, 64.8 (2.8) years]. Muscular strength, power and functional testings were conducted before the initiation of training (T1), after 12 weeks (T2) and after 6 weeks of DT (T3). During the 12 weeks of training, EG significantly increased their dynamic strength performance (range from 41.9 to 64.1%), muscle power output (range from 18.2 to 33.6%) (p<0.05) and function (15.8%) (p<0.05). No significant differences were observed in the magnitude of the increases in CG. Short-term DT led to larger effects on maximal strength (18.1-23.8%) (p<0.05) of both upper and lower extremity muscles than in muscle power (2-4.5%) and function (2.8%) (p<0.05). However, all measurements remained higher (12.6-36.4%; p<0.05) than in pre-training levels. These data indicated that DT may induce larger declines in muscle strength than in power output and preserved physical independence, mediated in part, by the effectiveness of high-speed power training particularly developed for older women.