It doesn't matter how you spread out your workouts—what really matters is how much total stress your muscles have been under over weeks or months, just like how your total food intake over time decides if you gain or lose fat.

To keep getting bigger and stronger muscles, you gotta slowly make your workouts harder over time—either lift heavier weights, do more reps, or do more sets.

If you get much stronger—like more than 20% stronger—on an exercise you’ve been doing for a long time, it probably means your muscles got bigger, not just your brain getting better at telling your muscles to work harder.

Your muscles grow bigger mainly because of how much total force they feel over time—not whether you do your workouts all at once or spread out over the week.

People grow muscle at very different rates — but each person tends to grow their arms and legs similarly, no matter what weight they use. This means your genes and biology matter more than how heavy your weights are.

If you train hard enough to fail on every set, how heavy the weights are matters less than your body’s natural ability to grow muscle.