Volume load is used to quantify the weight lifted during a workout. It's a way to measure training volume, taking both the weight used and the number of reps into account. Volume Load= reps x sets x weight. The problem is that it only measures external training stress. Ex 1: 10 sets x 1 rep x 100kg = 1000kg Ex 2: 1 set of 10 reps x 100kg = 1000kg Even though the volume is the same for both workouts, our perceived effort will differ. Internal load is what drives adaptations. Perception of effort is an indirect and subjective way measurement of internal load. Measuring metabolic stress is one way to assess internal straining stress. This study breaks down how different set configurations affect internal load (PMID: 34132222) Results: The 6x4 protocol demonstrated superior mechanical performance (force, velocity, and power) and fewer signs of neuromuscular fatigue. The 3x8 protocol led to higher lactate and ammonia levels, a more pronounced decrease in jump height, and more signi...