When doing slow, gentle weight training for your whole body, your muscles get just as tired and produce the same chemical buildup as fast, hard training—even though you're not lifting as heavy. This means your body is working hard in a different way to make the exercise effective.

A lighter workout style called LST can make your muscles produce as much lactic acid as a harder workout called HN, which might help build muscle size just as well, even though it's less intense.

When trained men do certain types of weightlifting workouts, their bodies produce more lactic acid compared to other workout styles, which means their muscles are working harder and under more stress.

When men who already lift weights do lots of reps with lighter weights, their muscles produce more lactic acid buildup than when they lift heavy weights for fewer reps, both right away and after two months of training.

A certain type of weight training keeps your muscles working non-stop, making them use more oxygen and possibly grow bigger because of changes inside your body.

If you wear tight bands around your arms or legs only when you're resting between weightlifting sets, your muscles will produce more lactic acid afterward than if you wear them while lifting or not at all—but that extra burn doesn’t make your muscles grow bigger or stronger.