If elite male judo guys do bicep curls with dumbbells twice a week for six weeks—whether they go super fast with light weights, lift heavy until they can’t anymore, or go fast without pushing to failure—their biceps still get thicker and stronger, even during their competition season.

For male judo athletes who are already pretty advanced, lifting heavy weights for 6 weeks might build more muscle and strength than doing fast, light lifts—even if both workouts push muscles to the max.

For elite male judo players, doing explosive strength training with light weights—without pushing to the point of exhaustion—works just as well or even better for building muscle and strength than going until their muscles give out.

If new guys do a specific arm curl workout for 10 weeks — going until their muscles are totally tired — their arm muscles get about 7% to 9% thicker, no matter how their shoulders are positioned, as long as the movement and resistance stay the same.

Doing bicep curls leads to bigger arm muscles (11% growth) than doing dumbbell rows (5% growth) after training for 8 weeks, at least in men who haven't exercised before.

If new gym guys do a specific arm curl workout for 10 weeks — going until their muscles are totally tired — their biceps get about 7% to 9% thicker, no matter how their shoulders are positioned, as long as the movement and resistance stay the same.