I'm extremely self conscious about my weight. A lot of the time, such as now, I feel as though I am overweight. When I was a child, I was overweight and teased mercilessly in school about it. In high school, I lost the weight, but I still believe, maybe falsely, that I'm overweight to this day. When I look in a mirror, I see an overweight person.
Every day, seven days a week, I have to run. I mean I have to, even if I am tired and don't want to. Rain, snow, shine, I run. After the run, it is only time that I feel somewhat okay. If I don't run, I feel down and, of course, overweight. I think I overdo the running, and I punish myself more when I think I have overate the day before. Feeling like I am overweight always adversely effects my mood.
I'm always reluctant to go to lunch or dinners because of this issue. During Sunday morning services, in the back of my mind, I'm thinking about getting to the park as soon as services are over to satisfy my need to run, which I know is completely wrong. I should be devoting myself fully to God. I don't have this problem in the evenings as I have already finished running and I am able to concentrate fully on the Bible study.
What do I do?† Maybe I have a skewed image of myself? There are plenty of times, such as after work, that I don't want to run and would actually like to go home and relax and read my Bible.
Your case isn't unheard of. While women have problems with compulsive dieting, it is generally middle aged men who run into problems with compulsive exercising. There are even books on the condition, such as "Compulsive Exercise and Eating Disorders."
Using feelings is not a good method of making decisions because the standard shifts. (See: Standards of Authority.) When a guy gets into compulsive running, whatever he does is never enough (the standard shifts). You see yourself as overweight, but if you compared yourself to standard scales (not your feelings) how would you measure up? I suspect you would find yourself at average or skinnier than average. Thus, you need to measure yourself by an impartial standard and not your personal feelings -- doing so will give you more control.
"And everyone who competes for the prize is temperate in all things. Now they do it to obtain a perishable crown, but we for an imperishable crown. Therefore I run thus: not with uncertainty. Thus I fight: not as one who beats the air. But I discipline my body and bring it into subjection, lest, when I have preached to others, I myself should become disqualified" (I Corinthians 9:25-27).
Paul uses the concept of athletics to illustrate some important spiritual points, but I would like to turn this around to note the points about athletics that should be obvious.
Run for the prize
Yes, your mood improves when exercising because it releases serotonin that improves your mood. You feel that you've accomplished something, even if it is only temporary. There is no problem enjoying what you accomplish, but it becomes a problem when you can't accomplish other things and still find enjoyment.
Temperate in all things
When you were a teenager, about 50% of all boys go through a phase of weight gain before they shoot up and mature. You would have probably slimmed down anyway, but you took up running, which isn't a bad thing by itself. The problem is that you have it fixed in your mind that any stoppage will mean an automatic weight gain.
Being temperate in all things includes temperance in running. Even good things can be overdone. To get the maximum benefit from any exercise, there has to be a recovery time.
Run with certainty
So rather than let your feelings run (and ruin) your life, I would like you to use your head. Make a three month training program that you know†is sensible and doable, and then stick to it. That means having at least one day per week scheduled as a recovery day. On that day you do stretches after a brief warm up, but no hard exercising and no running. Alternate days when you go hard, go for distance, and some easy short runs. Do not go beyond what you have already planned. You can miss a day, but you can't make up for it or run beyond what you have planned. Mix things up. Run different courses. Run in different directions. Run different speeds and different lengths of time. The idea is to break the compulsion by not always doing the same thing -- which includes forcing yourself to take a day off.
Once you've gotten used to scheduling your running and sticking to your plan, change your routine some more. Instead of running, one day each week substitute a different type of exercise. You will still be burning calories, but again, you'll be breaking the compulsion that it has to be done exactly the same way.
In regards to meals, plan what and how much you will eat before hand. For example, plan that you will have a piece of meat the size of your palm, two sides the size of your fist, and either no desert or one desert that is half of a normal serving. If you are at a restaurant, before you eat, mark out what you plan to eat and either push the extra off to the side or ask for a "to-go" box immediately and put the extras in there for another meal later. By controlling your intake, you won't feel the need as strongly to burn off what you ate because you know you didn't overeat.
But in the end, exercise is about this life. It has benefits, but it can't do you well in the long run. "For bodily exercise profits a little, but godliness is profitable for all things, having promise of the life that now is and of that which is to come" (I Timothy 6:11).