Low Frequency Severe-Intensity Interval Training Markedly Alters Respiratory Compensation Point During Incremental Exercise in Untrained Male

Abstract

This study investigated the effect of low-frequency severe-intensity interval training on the respiratory compensation point (RCP) during incremental exercise test. Eighteen healthy males (age; 20.7 ± 2.2 years, range 18 to 29 years, height; 174.0 ± 5.6 cm, weight; 68.8 ± 13.5 kg) were randomly assigned to an interval training group or a control group. Interval training was conducted once weekly for 3 months. Each session consisted of three bouts of bicycle ergometer exercise at 80% maximum work rate until volitional fatigue. Before (baseline) and after the 3-month intervention, incremental exercise test was performed on a bicycle ergometer for determination of ventilatory threshold (VT), RCP, and peak oxygen consumption (V O2 peak). The training program resulted in significant increases ofV O2 peak (+ 14%, p < 0.001, η 2 p = 0.437), oxygen consumption (V O2) at VT (+ 18%, p < 0.001, η 2 p = 0.749) and RCP (+ 15%, p = 0.03, η 2 p = 0.239) during incremental exercise test in the training group. Furthermore, a significant positive correlation was observed between the increase inV O2 peak and increase inV O2 at RCP after intervention (r = 0.87, p = 0.002) in the training group. Tidal volumes at VT (p = 0.04, η 2 p = 0.270) and RCP (p = 0.01, η 2 p = 0.370) also increased significantly after intervention compared to baseline. Low-frequency severeintensity interval training induced a shift in RCP toward higher work rate accompanied by higher tidal volume during incremental exercise test.

High-intensity interval training improves respiratory and cardiovascular adjustments before and after initiation of exercise

“…The HIIT group conducted high-intensity interval training at a frequency of one session per week for 8 weeks ( Figure 1A ). The exercise training program involved bicycle ergometer exercise as described in our previous report ( Nakahara et al, 2015 ; Nakahara et al, 2020 ). Each training session consisted of three bouts of exercise at 95% maximal work rate (WR max ) until exhaustion.…”