Effects of ischemic training on leg exercise endurance.

This study tested whether ischemic exercise training (Tr(IS+EX)) would increase endurance of ischemic (Ex(IS)) and ramp exercise (Ex(RA)) knee-extension tests more than exercise training (Tr(EX)) alone. Ten healthy subjects performed pre- and posttraining tests with each leg. For Ex(RA), after subjects warmed up, a weight was added each minute until they were exhausted. Ex(IS) was similar, but after warm-up, we inflated a thigh cuff to 150 mmHg instead of adding weights. One leg was chosen for Tr(IS+EX) (cuff inflated to 150 mmHg during exercise) and the other for Tr(EX), both with a small weight on each leg, four to six times per daily session for 3 to 5 min each, 5 days per week for 6 weeks. Ex(IS) duration increased 120% more (p = 0.002) in the Tr(IS+EX) leg than in the contralateral Tr(EX) leg, whereas Ex(RA) duration increased only 16% (nonsignificant). Tr(IS+EX )and Tr(EX) significantly attenuated the ventilation increase (ergoreflex) during Ex(IS). TheO(2) debt for Ex(IS )was significantly lower and systolic blood pressure recovery was faster after Tr(IS+EX) than after Tr(EX). Heart rate recovery after Ex(RA )andEx(IS )was faster after Tr(IS+EX). Apparently, Tr(IS+EX) with low-intensity resistance increases exercise endurance and attenuates the ergoreflex and therefore may be a useful tool to increase regional muscle endurance to improve systemic exercise capacity in patients.