Lifting very heavy weights (4 reps max) might lead to more injuries and takes more effort, while lifting lighter weights (8 reps max) gives similar muscle and strength gains with less chance of getting hurt and saves time for beginners.

Lifting weights in a certain way (doing 4 sets of 8 reps) gives the same muscle and strength benefits as another method (7 sets of 4 reps) in young men who are new to training, but it takes almost half the time per workout.

Lifting heavier weights makes untrained men much stronger than lifting lighter weights over 8 weeks, even if both types of training are done until you can't lift anymore.

When beginners lift weights for 10 weeks, doing fewer reps with heavier weights (like 4 or 8 reps max) builds more strength than doing more reps with lighter weights (12 reps max), even if the total work is the same.

When men lift weights, doing more reps with lighter weights (like 12 reps max) gives less strength improvement than doing fewer reps with heavier weights (like 4 or 8 reps max), even if the total workout effort is the same.

If you lift the same total amount of weight, lifting heavier weights (80% or more of your max) makes you stronger in a single big lift than lifting lighter weights—but lifting very light weights and light weights (under 60%) give you about the same strength gains.