Ischemic Conditioning Between Maximal Isokinetic Exercise Bouts Attenuates Cardiovascular Responses Without Affecting Muscle Performance
摘要
Ischemic conditioning (IC) enhances exercise performance by improving cardiovascular efficiency and reducing perceived exertion, possibly through suppression of the exercise pressor reflex. However, its effects between repeated bouts of exercise remain unclear. This study investigated its effects on cardiovascular responses, muscle strength, and perceived exertion during maximal isokinetic exercise. We hypothesized that IC would attenuate cardiovascular responses and limit peak torque decline, helping to sustain performance.
MethodsSeventeen healthy adults participated in a randomized, single-blind, sham-controlled crossover study, performing 30 maximal isokinetic knee extensions in two sessions separated by a 30-min interval. During this interval, they received either IC (three 5-min cycles of 220 mmHg thigh cuff inflation, interspersed with 5-min deflations) or a sham intervention (20 mmHg inflation). Measurements included cardiovascular responses (systolic and diastolic blood pressure, heart rate, and rate-pressure product), blood lactate concentration, peak torque, and perceived exertion.
ResultsCompared to the sham intervention, IC significantly reduced the change in rate-pressure product from the first to the second exercise bout (P = 0.03, Cohen’s d = 1.05). However, it had no significant effect on systolic or diastolic blood pressure, heart rate, blood lactate concentration, peak torque, or perceived exertion (all P > 0.05).
ConclusionApplying IC between repeated bouts of maximal isokinetic exercise attenuated cardiovascular responses, as indicated by a reduced rate-pressure product, without affecting muscle strength or perceived exertion. These findings suggest that IC may help manage cardiac load during high-intensity exercise while preserving performance, potentially benefiting athletes or individuals with cardiovascular concerns.