GOT KNOTS? February 15, 2016 PROBLEM: I’ve got knots/lumps in my muscles. WHAT KNOTS ARE NOT: At one time, it was thought that knots were from a build-up of lactic acid (lactic acidosis). Lactic acidosis is a result of intense exercise. When you exercise, your body uses oxygen to break down glucose for energy. During vigorous and extended activity (i.e. running a marathon), enough oxygen may not be available. When oxygen levels drop, the body metabolizes glucose anaerobically for energy, leading to lactate formation. Normally the body processes out the lactate quickly, but under extreme conditions, lactate may build up. (Sometimes lactic acidosis can be a side effect of medication.