Muscle injuries and dehydration can also trigger cramps. Dehydration is the excessive loss of fluids in the body. Low levels of any of the following minerals that contribute to healthy muscle function may also cause muscle cramps: calcium.
The heart is a part of the cardiovascular system in fact its the main part so if you have heart disease another way of saying this is you have cardiovascular disease.
The type of exercises you do also affects the number of calories you can burn. Doing circuits of weight exercises broken up with cardiovascular exercises with little to no break time in between will burn more energy than maxing out and resting 5, 10 or 15 minutes in between sets of exercises.