The long and short of the answer is... it depends on what stage of training you are in and what the training goals are. I f you are an elite athlete whose goals are maximal performance come game day, then when your body is telling you its sore your next step should be to rejuvenate it to enable maximal performance. However if you goal is to get a bigger more muscular frame then sometimes you will be training under at state of muscle soreness.
DOMS is caused by the breakdown of proteins within the body, molecules such as creatine kinase are secreted into the blood stream causing a sensation of soreness and stiffness in the muscles. Since muscle building and exercise in general causes micro trauma designed to breakdown proteins in order for rest and nutrition (protein digestion) to rebuild them back up bigger and stronger it is no surprise that when we push our limits this soreness can last up to 72 hours.
Typically the best strategies to reduce DOMS are to take on a high protein food intake especially immediately post-training, to stretch and to perform a recovery session such as massage, ice baths or a class such as yoga. These modalities will reduce your risk of long term injury and enable you to continue training in the gym. A further good idea is to rotate body parts or change the type and duration of your training, essentially to mix it up! It keeps your body guessing which causes adaptation without over exhausting a single area.
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