This study examined whether home-based, high-speed calf-raise training changes the rate of torque development during plantar flexion contractions and balance performance in elderly men. Thirty-four healthy elderly men (73 ± 5 yr) were randomly assigned to a training or control group (n = 17 in each group). The subjects in the training group completed 8 weeks (3 times/week) of home-based bilateral calf-raise training using body mass. Before and after the intervention, rate of torque development during plantar flexion contractions and center of pressure displacement during single-leg standing were measured. Surface electromyographic amplitude of the triceps surae and tibialis anterior during the strength and single-leg standing were measured. Clinical magnitude-based inferences were used to interpret the training effect, with smallest worthwhile effect being assumed to be 0.2 of the baseline standard deviation. The peak rate of torque development increased 21% (90% confidence limits, ±19%) relative to control group, which was accompanied by corresponding changes of the medial gastrocnemius and soleus activations. The effect on center of pressure displacement was possibly trivial (0%; ±13%), whereas substantial reduction in the medial gastrocnemius (-19%; ±15%) and soleus (-25%; ±13%) activations during standing was observed. Our findings indicate that calf-raise training at home, performed without special equipment or venue, induces a substantial increase in the plantar flexors’ rapid force generating capability and triceps surae activations. Although the training effect on standing balance performance was not substantial, observed changes in the triceps surae activations during standing are expected to contribute to future balance performance improvement.
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