When your brain stops working because you've eaten too few calories, or you feel pain that is different from muscle soreness, take a day to stop and regroup. It's ok to take a day off working out here and there when you need it, but it doesn't mean you get a free pass to go home and binge. If you're dieting, your stomach will take some time to adjust to the smaller portions. When this happens, distract your mind with family and friends (just make sure they know you're dieting and not to tempt you). If weight loss is your goal, then making sure your calorie deficit is close to your daily goal. There's no need to burn out in the first couple of weeks and ruin your progress yo-yoing on and off your routine. After a few hard workouts, your muscles are probably taunt and sore. It's hard to go up and down stairs, and you are reminded of it every time you move. Although it would be best if you can muster the willpower to work through it, there's no one you have to prove yourself to other than yourself. Only you can be the judge, and learn your own balance. Until tomorrow, eat something sensible, get some rest, and strengthen your resolve to have another great day in the morning.