Phew, a lot of bad things can happen to your body when you are sedentary. Your muscles and bones can shrink, parts of your endocrine system malfunctions, and you can become diabetic. Your nervous system plays tricks on your mind, and you can become depressed.
Your body functions better when it is active and physically fit. Your heart and lungs work more efficiently, so they circulate oxygen with less effort. Your digestive tract absorbs more nutrients and can get rid of waste more easily. Furthermore, your nervous system can detect sudden changes in the environment, which will help you react to prevent injury. Strong bones and muscles hold your body together and keep you standing tall.
All together, with an active lifestyle, you can become a well-polished machine ready for the road.