Neural training for quick strength gains in the elderly: strength as a learned skill
A sample of 20 older adults (76 +/- 6 years) participated in a two-session training intervention with the goal of eliciting rapid and functionally meaningful strength gains in the ankle plantarflexors. Tests were conducted on a Monday-Wednesday-Friday schedule with two training sessions after tests one and two. During each test, subjects performed five maximal explosive force production contractions (MVCs) from which maximal voluntary torque (MVT) and peak rates of torque development (RTDs) were obtained. To augment the quick strength gains typically observed in response to serial strength measurements, these MVCs were supplemented with exercises consisting of high-velocity, low-force movements at the ankle joint. These exercises were chosen to elicit high rates of neural stimulation without high resistance. Maximal voluntary torque increased by 15% from 53.9 +/- 36 to 62.2 +/- 36.2 N x m (p = 0.02). There was a parallel trend toward increases in RTD based on RTD measures computed over various timescales (0.11 < p < 0.21). The nonsignificant increase in RTD was from 223.9 +/- 153.6 to 248.4 +/- 147.8 N x m x s(-1). This preliminary study has determined that rapid strength gains of functional magnitude are possible in the plantarflexors of the elderly. Subsequent work is necessary to test the translation of such gains to function in the frail elderly and to determine the specific contributions of the selected low-resistance exercises to overall gains.