DOMS (delayed onset muscle soreness) is the pain you experience in the days following your workout. Now your body needs to use the nutrients you have been eating to rebuild your muscles, making the muscle fibres you damaged bigger and better and ready for more. This is your body’s way of coping with and adapting to the stress of training.
This whole process is calorie burning and the bigger your muscles grow (fear not ladies!) the less bodyfat you will have. But that recovery time is crucial. Overtraining is counterproductive. So, sometimes, less is more!