The one I had was cheap and consists of fasting the night before then breathing in to a machine for 15 minutes. It measures the amount of oxygen your body burns in your breast to calculate your resting metabolic rate which then gives you the base number of calories your body burns a day if you did absolutely nothing.
They should then give you a recommended reasonably accurate number of calories to eat depending on your goal and lifestyle. This means you can calculate a reasonable surplus without going overboard and just getting fat.
Also if progress is slow gaining muscle, remember for the majority of people it’s is a long slow process. A lot of the rapid transformations/strength gains we see have help from synthetic testosterone which is a completely different ball game.
The one I had was cheap and consists of fasting the night before then breathing in to a machine for 15 minutes. It measures the amount of oxygen your body burns in your breast to calculate your resting metabolic rate which then gives you the base number of calories your body burns a day if you did absolutely nothing.
They should then give you a recommended reasonably accurate number of calories to eat depending on your goal and lifestyle. This means you can calculate a reasonable surplus without going overboard and just getting fat.
Also if progress is slow gaining muscle, remember for the majority of people it’s is a long slow process. A lot of the rapid transformations/strength gains we see have help from synthetic testosterone which is a completely different ball game.