When i stretch my arms and legs i get a burning sensation in my muscles that last about 3-5 seconds?

May be normal: Hard to say, but with stretching and working out the muscles, sometimes the stretch is intense enough to create a burning sensation to to Lactic Acid buildup. If this happens quite often, with minor stretching, i might consider seeing a dr. Make sure you are well hydrated and take magnesium/potassium supplements, which may help. But first consult a dr.