Feeling sore after workouts? Delayed onset muscle soreness (DOMS) is a normal side effect of the stress put on muscles during exercise. It occurs because: - Muscles experience micro-tears that get inflamed as they heal - Lactic acid and other waste products accumulate within muscles any experienced <a href="https://www.personaltrainingmaster.co.uk/personal-training-west-london/">personal trainer west London</a> will ask you to warm-up in order to avoid soreness. However, this isn’t the only way!