There really can be gain without pain. Soreness isn’t a prerequisite for building muscle, an analysis in the Strength and Conditioning Journal concludes. After reviewing the science, study co-author Professor Brad Schoenfeld determined that aches, while they might signal that you’ve damaged the muscle enough for it to repair itself and grow, are not necessary for gains. Plus, he says, “too much soreness can impede your ability to work out again.” Haven’t trained for a few weeks? Minimise discomfort by lifting 20% lighter than your norm and stop 
two reps short of failure in your first two workouts.

Check out the video below, brought to you by Mental Floss, to see other misconceptions about exercise: