Effect of short-term low-intensity strength training with skin cooling over working muscle on neuromuscular function and physical activity among elderly women

Abstract

  The stimulation of skin cold receptors over the working muscle induces high-threshold motor unit recruitment during low-intensity contraction. Moreover, skin cooling at a lower temperature over the agonist muscles increases electromyography activity and the rate of force development (RFD). The current study aimed to examine the effect of short-term low-intensity strength training with skin cooling over the agonist muscles on leg extension force, RFD, and physical fitness among 11 elderly women. The participants were divided into the skin cooling group and the control group, and they carried out strength training, which comprised 50 repeated knee flexion exercises using an elastic band for 7 weeks. Post-training handgrip power and walking speed significantly improved compared with the baseline levels in both groups. However, the knee flexion force did not increase. The RFD at 0-100 and 0-200 ms significantly increased in the skin cooling group compared with the control group. A weak correlation was observed between the changes in RFD and walking speed. These results suggest that even low-intensity resistance training could be an effective as introductory training for the elderly. Moreover, the addition of skin cooling during training could reinforce instantaneous muscle activity.