Minimum load threshold in resistance training: insights into muscle metabolism, excitation, and fatigue across the repetition continuum - PubMed
4 hours ago
- #critical load
- #resistance training
- #muscle fatigue
- Low-load resistance training (<50% 1RM) is gaining attention for its practical and physiological advantages.
- The study investigates physiological responses, fatigue, and recovery during concentric-only resistance training across a spectrum of % 1RM.
- Participants performed exhaustive unilateral leg extensions at 10%, 30%, 50%, 70%, and 90% 1RM, with measurements of muscle deoxyhaemoglobin, muscle excitation, heart rate, blood lactate, and rate of perceived exertion.
- Results showed that 30%, 50%, 70%, and 90% 1RM protocols induced muscle failure and similar metabolic perturbation, while 10% did not lead to failure.
- Muscle excitation increased with higher external loads, and fatigue was moderately correlated with metabolic markers.
- The critical load (CL) was detected at approximately 31.7% 1RM, suggesting a minimal load threshold for effective resistance training.
- The study provides insights into determining the minimal load threshold in resistance training and suggests proximity between CL and blood flow occlusion during contraction.