When you're lifting weights, whether you do exercises that target one muscle at a time or ones that work multiple muscles together can change how well we can guess how much muscle you'll build or how much stronger you'll get—and using a special way to measure the workload (called 'fractional') works best for making those guesses.

Not all sets count the same—sets that directly target the muscle you're measuring matter more, and a method that gives partial credit to indirect sets works best for predicting results.

Some trainers count all your lifts to measure workout effort, but this new method gives half credit to exercises that don’t directly work your main muscles—like warm-ups—and it turns out this way predicts muscle growth and strength gains better than the old ways.

Some trainers count all your lifts to measure workout volume, but this claim says a smarter way is to count only the hard sets fully and give half credit to the lighter, supporting ones — and that this method actually predicts muscle growth and strength gains better than the other ways.

If you're a young guy lifting weights, your muscle growth and strength gains might be easier to predict if you treat big multi-muscle exercises (like squats) differently in your workout plan than isolated moves (like bicep curls).

How you count your weightlifting sets—whether you count every little part or just the full sets—can change how we think about how much lifting helps you get stronger versus bigger muscles.