Cortisol is a word you should become familiar with, as it's a key factor here. You've probably heard that it makes you fat, but you have no idea why "they" say that. What is cortisol? It's actually a performance-enhancing stress hormone that serves an important function in survival situations. Unfortunately, when we force too much daily stress on our bodies, we shift into a state of chronic cortisol release. This can cause us to store excess fat as a survival instinct. While it sounds pretty dire, it's generally only a serious problem in those with poor lifestyle habits.
The beginning of a diet and/or exercise program, however, is a survival situation. In a very simplistic sense, your body releases cortisol, which, in turn, causes excess water retention to help you rebuild broken down muscle tissue. While this is cortisol functioning properly, it does lead to a period of water weight gain as you adjust to a new program. It's nothing to worry about. By following a solid plan, your body will adapt by repairing this muscle tissue. This results in an increase in your metabolism and leads to weight loss if that's your goal.
The trick is that there is no hard line on how long this adaptation takes. It's based on your individual parameters. Just rest easy in the fact that it will happen, unless you force it not to, leading us to . . .
I'm barely eating.Severe undereating causes cortisol release, as it's the definition of a bodily emergency. Beachbody® offers many kick-start (or express) eating plans where you undereat for a few days, but you're always encouraged to get back to a solid maintenance calorie level quickly. A short period of strategic undereating with proper hydration will help your body dispense of unneeded food (most of us chronically overeat) and regulate bodily functions. Go too long, however, and chronic cortisol release is the result.
This is a tough situation because our natural reaction to weight gain is to eat less. When you're exercising, it's important to keep your eye on workout performance, as opposed to how much weight you're losing. You should be eating enough so that your daily workouts improve over time. As long as that's happening, your body is adapting, your metabolism is increasing, and you will lose weight provided you also don't overeat.
On the performance theme, you need to continually improve, which is why workouts get harder as you move through any of Beachbody's programs. It's also why we add resistance (via added weight or gravity, as is the case with jumping) to workouts. If you're doing the same workouts at the same intensity constantly, you are not forcing adaptations that lead to changes in your metabolism. This is called a plateau.
A plateau, technically, isn't gaining weight—it's remaining the same—but a proper diet and exercise program should continually force improvements (in the form of adaptations). Otherwise, your metabolism won't continue to increase, which is the goal of most weight loss programs.
Back to adaptation. We all react differently. The only absolute is that our bodies will change over time with a healthy program. A fitness rule called the Specificity of Adaptation states that it takes the body between 3 and 12 weeks to adapt to new stimuli, which is a very broad range. This is why it's vital that you stick to your program and not change it repeatedly based on your daily results!
In our test groups, two-week results have almost no bearing on who does best in the end. In fact, many people that undereat early and get off to a fast start will stagnate, while those who stick to the plan and eat as advised will start slower but train harder over time, leading to rapid weight loss as the program wears on.
I lost weight for a while but now it's stopped. For ages on the Team Beachbody® Message Boards, this was our most frequently asked question. You eat less to lose weight. Things are going great, but suddenly you plateau—or start gaining. Odds are, your metabolism has slowed down in order to deal with the decreased calories. You're starving your now fit body, so it's doing what it needs to do to survive. The answer to this problem is pretty simple: eat more.
Again, this is a tough sell, so here's an example. One of our early Success Stories lost 40 pounds during a round of Power 90®, eating only 1,200 calories a day. He then stagnated for a long time and was very resistant to eating more, fearing it would kick-start a regression. We talked him into adding calories until, finally at around 2,000 calories, weight loss resumed. It then became so rapid he dropped through his goal, and about 20 pounds below, until finally, at around 3,000 calories, he leveled out. Then a daily diet of around 3,500 calories a day got him to a ripped 175.