If you slowly increase your workout volume over time, your body adapts and you're less likely to get overly tired or burned out compared to jumping into intense workouts all at once.

When you keep working out, your muscles get used to it and don’t get as sore or damaged each time—so you can train harder and more often, which helps you build more muscle over time.

When lifting weights until complete exhaustion, the total number of repetitions performed across all sets is lower than when stopping one repetition before failure, because fatigue reduces performance in later sets, even if the first set has more reps.

If you’ve been lifting for a while, doing more workouts over time will help you build more muscle than just lifting heavier weights.

Lifting very heavy weights for fewer reps makes well-trained young men feel more tired and worn out than lifting lighter weights for more reps, which might make it harder for them to do extra workouts over 8 weeks.

When people do really intense weight training, not everyone gets overly tired or performs worse — in fact, more than half of the studies didn’t see a drop in performance.