Short-term high-intensity interval and continuous moderate-intensity training improve maximal aerobic power and diastolic filling during exercise

摘要

Purpose: This study examined the effects of short-term high-intensity interval training (HIT) and continuous moderate-intensity training (CMT) on cardiac function in young, healthy men. Methods: Sixteen previously untrained men (mean age of 25.1 ± 4.1 years) were randomly assigned to HIT and CMT (n = 8 each) and assessed before and after six sessions over a 12-day training period. HIT consisted of 8-12 intervals of cycling for 60 s at 95-100 % of pre-training maximal aerobic power (V V ? O2max), interspersed by 75 s of cycling at 10 % V V ? O2max. CMT involved 90-120 min of cycling at 65 % pre-training V V ? O2max. Left ventricular (LV) function was determined at rest and during submaximal exercise (heart rate ~105 bpm) using two-dimensional and Doppler echocardiography. Results: Training resulted in increased calculated plasma volume (PV) in both groups, accompanied by improved V V ? O2max in HIT (HIT: from 39.5 ± 7.1 to 43.9 ± 5.5 mL kg-1 min-1; CMT: from 39.9 ± 5.9 to 41.7 ± 5.3 mL kg-1 min-1; P 0.001). Resting LV function was not altered. However, increased exercise stroke volume (P = 0.02) and cardiac output (P = 0.02) were observed, secondary to increases in end-diastolic volume (P 0.001). Numerous Doppler and speckle tracking indices of diastolic function were similarly enhanced during exercise in both training groups and were related to changes in PV. Conclusion: Short-term HIT and CMT elicit rapid improvements in V V ? O2max and LV filling without global changes in cardiac performance at rest.