I am cutting weight for a martial arts tournament and my legs are aching all the time. what is this? will it go away once i switch to my normal diet?

DOMS: Delayed onset muscle soreness is something that may occur with overuse of muscles and inadequate rest; if there is insufficient rest, it may become ongoing until you ease off; as to your diet, if you are using some "new" supplements, these might also cause muscle soreness, depending on what is in them;.

Stay hydrated! : May be musculoskeletal in nature from your workouts, however....Stay very well hydrated, consider multivitamin, sometimes can be related to potassium deficiency (excessive sweating etc.). A banana a day will not cream your weight cutting, there is a fine balance between weight cutting and dehydration and at 16 years old, watch your health (i know wrestlers everywhere are groaning....).