- Exercise makes you hungry so you eat more than you normally would (and often more calories than you just burned).
- Exercise makes you think you are entitled to treats. "I deserve this doughnut, I went to the gym this morning."
- Exercise makes you tired so you are less likely to move when you get home from the gym (as in less likely to take the stairs, go to the grocery store to shop for dinner, vacuum, rake the leaves, etc).
I've actually known about this for a long time. Back when I swam on swim team, I never lost any weight, despite the fact that I swam for two hours a day. Swimming for two hours every day burns a lot of calories and I was always starving when I got home so I ate... a lot. Then, when swim season was over, I would gain a few pounds because I was in the habit of eating when I got home from school and I had to train myself to remember that I didn't just burn 5,000 calories.
I'm not going to quit the 30-day Shred because I'm no quitter. But, I am going to give up on my expectations that it's going to help me lose that last 5 lbs... and probably try to cut back on my cookies consumption. But, not too much, because I deserve those cookies. Don't I?