Doing leg presses burns way more calories than doing chest flys—even if you do the same number of reps—because your legs use more muscles and keep burning energy longer after you finish.

Your body burns more calories after leg presses than after chest flys—even if you rest the same amount—because your legs use way more muscles and need more oxygen to recover.

When doing leg presses, taking only 1 minute of rest between sets makes you breathe harder overall than taking 3 minutes, but this doesn’t happen when doing chest flys—your body handles short breaks better when using smaller muscles.

After lifting heavy with your legs, your body keeps burning extra calories for about 40 minutes—but after doing chest flys with long breaks, it only lasts 20 minutes.

Right after leg presses with only 1-minute breaks, your body gasps for air more intensely in the first minute than if you took 3-minute breaks—but this doesn’t happen with chest flys.