After two sessions of exercise the common human reaction is too look in the mirror and expect visible results.
This is another important thing to realize.
Step on your bathroom scale and note the weight. Now, step off. Watch the second hand on your watch go around once. Step on again and note the reading. Step off. Wait another minute. Step back on and note the third reading. I'll bet you there's at least a pound of variance among the three readings, maybe two or more. What do you expect for ten bucks worth of bathroom scale? Even expensive, digital scales will have a pound of variance in three consecutive readings.
I've found that I can loose a couple of pounds by sitting in the sauna for a half hour. That's not real weight loss. What this illustrates is that the amount of water in your body can swing your weight a couple of pounds. Sitting in a sauna for a half hour is a bit of an extreme case, but other things can influence the amount of water in your body.
As a result of all of these factors, people often start a diet and exercise program, they cut back 500 calories per day, they do a half-hour of exercise every other day, and then they weigh themselves at the end of the first week and find, for all of their sacrifice and hard work, they've gained a pound. And that can be discouraging.
Good, healthy, real, sustainable weight loss will average about one to two pounds per week. But, water retention can swing your body weight a pound or two and even a good scale has a pound or two of variability in it. So, it may be several weeks before you start to see the scale trend down.
If you weigh 200 lbs, one pound is one half of one percent. A loss of one pound will not be visible; you're not going to tighten your belt a notch because of it. So, do not be discouraged if, at the end of the first week or the second or the third, you don't look any different, your belt is no tighter, and nobody has noticed your weight loss.
Five percent is significant. You will see five percent in the mirror. You may not be able to tighten your belt a notch yet at five percent, but your pants will be noticably looser. And perceptive people will start to say, "You've lost weight." That's at five percent. For a 200 lbs person, that's after ten pounds of loss. If you're loosing 1-2 lbs per week, that will be five to ten weeks into your program, maybe two months.
Looking in the mirror and seeing yourself noticably trimmer, feeling your pants looser, especially having other people comment, these are real motivator. But they are realistically five to ten weeks away. You have got to motivate yourself through those first two or three months.