fatigue
The present study shows that HIIT 4 × 4 min is more effective than SIT with short (8 × 20 s) and long (10 × 30 s) recovery periods for improving V̇OIn accordance with our hypothesis, It is also noteworthy that during SIT with longer recovery periods, such as 10 × 30 s, the decrease in V̇OExercise at ~95% of MAS can be maintained for several minutes, while an intensity ≥150% of MAS necessitates very short intervals because fatigue occurs rapidly. This limits the capability of SIT protocols to accumulate as large volumes as HIIT protocols are designed to achieve, and any attempt to match for total work between such protocols would be futile. Essentially, one cannot combine a very high work output (≥150% of MAS) with a volume associated with less intense exercise (e.g., ≥ 10 min). However, it should be noted that the total work during the SIT protocols (excluding warm‐up, breaks, and cool‐down) were 29% (8 × 20 s) and 63% (10 × 30 s) of the total work during HIIT 4 × 4 min.The superior improvement in V̇O