If you are really as active as you say (exercising all day every day) then it is possible that you are simply over-fatiguing your muscles and this is leading to soreness and cramping. One way to address this is simply to take more rest days. Another is to alternate the types of exercise you are doing from day to day - this is the principle of "cross training" to build strength in muscles groups you do not usually use and to prevent fatigue of the ones you do.
The association between cramping muscles and having your stomach in knots also suggests that you may be getting yourself dehydrated with prolonged exercise. When the body works hard, it loses a lot of water and essential salts like sodium and potassium in the sweat. If this water and salt is not replaced, it can lead to imbalances in blood chemistry which can cause nausea, fatigue, and cramping. The solution, of course, is to take care to stay very well hydrated and perhaps to also drink a beverage that has some electrolytes in it. You should exercise particular caution with hydration when it is hot or sunny outside.
Talk to your primary care doctor
if you have more questions.