This doesn’t need to be longitudinal — the parent’s point seems to be much simpler: people who don’t work out will have quicker initial muscle gains upon starti

This doesn’t need to be longitudinal — the parent’s point seems to be much simpler: people who don’t work out will have quicker initial muscle gains upon starting than those who already regularly work out. This could be measured over a period of weeks but I wonder if it has been studied because it is so obviously true.