If you exercise infrequently, prioritize vigorous intensity. If you exercise frequently, prioritize moderate intensity.

noli's read

This advice is based on managing fatigue and biological efficiency. For sedentary individuals, vigorous (shorter) intensity yields marked cardio-metabolic benefits in a short timeframe, which is validated by public health recommendations. For high-volume athletes, a moderate approach helps manage recovery and avoid overtraining, a common observation in work capacity literature. Research confirms that total volume remains a key driver of health, but intensity provides specific benefits, particularly regarding aerobic capacity. The notion that high intensity is more effective for low volumes is supported by studies showing significant gains with limited time. However, the inverse adjustment (high volume with high intensity) is often discouraged due to systemic recovery concerns. The analysis is sound but must be adapted to individual tolerance, as is often highlighted by Greg Nuckols in his work.

the sources

1. 1Stamatakis E et al. 2022
2. 2Stamatakis E et al. 2023