Legs are your largest muscles trained through big ranges, so soreness runs deep, but too much volume or too little food makes it worse.
Legs are the biggest muscle group and squats, lunges, and Romanian deadlifts load them under a deep stretch, which causes far more muscle damage than upper body work. Extreme soreness usually means you did too much volume at once, added weight too fast, went unusually deep, or are under-eating and under-sleeping. Build up leg volume gradually, keep the harder eccentric moves in check, and fuel and sleep enough to recover.
Quads, glutes, and hamstrings are huge, and moves like deep squats and Romanian deadlifts stretch them under heavy load. That loaded-stretch eccentric causes the most muscle damage of any training, so deep soreness is partly normal, especially early on.
Doing 20-plus hard leg sets or suddenly adding big weight overshoots what you can recover from. Ramp leg volume up slowly, add load in small increments, and your soreness will settle into a manageable range within a few weeks.
Under-eating, low protein, and poor sleep leave your legs unable to repair, dragging soreness out for days. Hit 1.6 to 2.2 g protein per kg, eat enough total calories, and sleep 7 to 9 hours to shorten recovery dramatically.
Legs are your largest muscles trained through big ranges, so soreness runs deep, but too much volume or too little food makes it worse.
