HI, I am a 55 year old male. Have been very healthy. Have lead an activity lifestyle, biking, swimming, and regular exercise. My diet is well balance. I do not sleep well. I am 6 4 and weight 185 lbs. Recently, I have had an constant upset stomach, joint pain, and muscular aches. I have noticed my strength and stamina have deteriated considerable. My primary physcian says it is old age . I m wondering if it could be something else. Any thougths?