Effects of ischemic training on leg exercise endurance.

This study tested whether ischemic exercise training (TrIS+Ex) would increase endurance of ischemic (Ex,S) 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 EXRA, 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 TrIS+EX (cuff inflated to 150 mmHg during exercise) and the other for TrEX, 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 TrIS+EX leg than in the contralateral Tr-EX leg, whereas Ex(RA) duration increased only 16% (nonsignificant). TrIS+EX and Tr-EX significantly attenuated the ventilation increase (ergoreflex) during Ex(IS). The O-2 debt for Ex(IS) was significantly lower and systolic blood pressure recovery was faster after TrIS+EX than after Tr-EX. Heart rate recovery after Ex(RA) and Ex(IS) was faster after TrIS+EX. Apparently, TrIS+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.