Having integrity and a clear conscience will keep your self-esteem up and self-esteem is pivotal to personal development! Do not cut corners, make excuses or give yourself other reasons to feel like you are not giving life your best effort. All of those little things will add up to a weight that will burden you with guilt and stop your success dead in its tracks, not to mention keeping you from getting a good night sleep.
Develop your body so that it becomes helpful to your success. You might have to work a lot so make sure your body is up to the task. Exercise regularly and go to a doctor at least once a year for a complete check-up. Take care of your body and it won't get in your way.