The effect of elevated muscle temperature on mechanical efficiency was investigated during exercise at different pedal frequencies in young and older women. Eight young (24 +/- 3 yr) and eight older (70 +/- 4 yr) women performed 6-min periods of cycling at 75% ventilatory threshold at pedal frequencies of 45, 60, 75, and 90 rpm under control and passively elevated local muscle temperature conditions. Mechanical efficiency was calculated from the ratio of energy turnover (pulmonary O(2) uptake) and mechanical power output.
View Article and Find Full Text PDFWe examined whether spontaneous baroreflex modulation of heart rate and other indexes of cardiac vagal tone could be altered by passive stretch of the human calf muscle during graded concurrent activation of the muscle metaboreflex. Ten healthy subjects performed four trials: a control trial, resting for 1.5 min (0% trial); or 1.
View Article and Find Full Text PDFThe purpose of the present study was to investigate the cardiovascular responses to muscle metaboreflex- and concurrent muscle stretch-induced mechanoreflex activation. Eight subjects (7 males, 1 female) performed 90 s of isometric calf plantarflexion at 0, 30, 50 and 70% of maximum voluntary contraction. During exercise and for 3.
View Article and Find Full Text PDFThis study investigated the cardiovascular response to a standard external muscle compression during concomitant muscle metaboreflex stimulation of varying intensity in human calf muscle. Eleven healthy male subjects (mean (s.d.
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