Before we analyze why you need to embrace "going backward," let's answer the obvious question: why would we design this type of program? Certainly, there are exercise programs that don't put you through torture. Could we have chosen such a path with P90X®?
The answer is that programs lacking this trilogy don't provide you an incentive to get in top shape. In the early stages of any exercise program, it's possible to structure the schedule and diet around making small improvements. I call this the Curves® template. You push your body above its normal output, though just barely, and you keep it there. If you are greatly deconditioned, it will yield improvements. This approach doesn't hurt, and frankly, it helps people who've never exercised—mainly due to the mental boost they get from feeling they can exercise. It's a nice alternative for some people. But let's be realistic. None of them would sit through a P90X infomercial, much less be inspired by it.
The Curves template is what we would call a foundation phase of training for someone who has never exercised. The next step would be one of our programs, like P90X or Slim in 6® (these programs also work on the Curves template because you can choose modified variations). The upside with this method is that each day you leave the gym feeling better than when you walked in. The downside is that you'll never have the body of a fitness model. To achieve a higher level of fitness, you need to periodize your training (see "Customizing P90X for Specific Goals: Part I" in the Related Articles section below) and eventually stare into your Nietzschean abyss. That which doesn't kill you makes you stronger is more than a cliché with P90X—it's your life.
Soreness is the easiest symptom to understand. Most of us have been sore at some point. It happens anytime we do something physical that we're unaccustomed to. From yard work to a pickup game with your old team to a marathon shopping spree, when you push your body beyond what you do in your normal day-to-day activity, you get sore. This is true even if you used to do the said activity all the time. In fact, that generally makes it worse, because you still hang on to the muscle memory of how to do the activity, which means you can really put the hurt on if you don't have the requisite fitness base.
Most soreness comes from the breakdown of fast twitch muscle fibers. Our bodies have both slow twitch and fast twitch fibers. Slow twitch fibers have a low recruitment factor, which simply means they get fired up at low outputs. Fast twitch fibers have a high recruitment factor, meaning it takes something more intense to get them going. A simple example would be raising your fork to your mouth, which requires slow twitch fibers, compared to raising a heavy barbell over your head, which requires fast twitch fibers. Furthermore, we all have some extra fast twitch fiber for emergencies. When you run from a bear, you're engaging these, which is why you're likely to run faster than you ever have before.
Fast twitch fibers are repaired much more slowly than slow twitch fibers. You can pretty much keep shoving food into your mouth and never get tired. When you do get tired, you'll be able to resume the activity quickly. Lifting a barbell over your head will wear you out, and it will take some time before your body is able to do it again. The more weight you add, the quicker you'll get tired and the longer it will take before your body is ready to do it again. And once you've escaped the bear, you'd do well to avoid him for a couple of weeks. Those emergency fibers you've thrashed will take that long to recover.
Hypertrophy means muscle growth. Almost all training programs target this, even weight loss programs, because changing a body from rotund to svelte requires you to lose body fat. And the quickest way to lose body fat is to gain more muscle. Muscle requires more work from your body, even at rest, so you're body will take the nutrients from the foods you eat and store them in muscle tissue rather than adipose (or fat) tissue.
To create hypertrophy, you need to overload your muscle fibers progressively to keep breaking them down. As you get fitter, you engage higher-threshold muscle cell motor units to keep the overload coming. Breaking down exactly the number of muscle cells your body can replenish right away is nearly impossible. This means that to advance your level of fitness, you are going to break down more muscle fibers than you intended. When this happens, you get sore.
"I heard I would get less hungry and all I can think about is eating" is a common sentiment expressed on our Message Boards. The reason is somewhat obvious—our entry-level programs have low-calorie diets, not to mention restricted diets. Most of these people are simply craving the junk foods we've had them cut out.
But Xers get hungry too, and they're usually eating enough calories. This is because your body cries out for nutrients when it's in breakdown mode, even when you've eaten all you can. Learning that this craving is normal will greatly help your success curve.
When your body is craving nutrients, you want to feed it. However, under the type of duress a hard program creates, you can't possibly give it enough nutrients. Many of us try. We eat and eat. And while eating can help ease the mental anguish your body is going through, you can't put all of these calories to use, and some will get stored in fat tissue.
But no matter how well we strategize, we're all going to get hungry at some point in our programs. So much so that staying hungry is a metaphor for the bodybuilding lifestyle. In the film Stay Hungry, a bodybuilding champion (played by Arnold Schwarzenegger) sums this up with the line, "I don't want to get too comfortable. I'd rather stay hungry."
This is the hardest condition to conceptualize but the easiest to explain. During hypertrophy, your muscles are growing. Growing muscles are a bit like a growing person. Just as you learn how to grow into a developing body, you need to learn how to use new muscles. During the hypertrophy stage of your exercise program, your muscles are "big and dumb," like the old-school concept of the "musclehead."
Larger muscles have a greater capacity for strength than smaller ones. A large muscle isn't necessarily stronger, but if trained properly, it will become stronger. Muscular efficiency (or absolute strength) is what gets targeted in the latter stages of a training program. Doing low repetitions, along with eccentric and plyometric movements, is all about teaching your muscles efficiency—essentially, the ability to recruit high-threshold muscle cell motor units.
We'll talk more about strength training in another article. Today, my point is to explain the rationale behind what I call "getting slow." While your muscles are growing, your ability to move quickly lessens. This is why athletes do all of their body-altering training in the off-season. When you start to feel slow, it's a sign that your program is working. Just remember that you'll want to increase your intensity and whip those big lugs into shape later on.
Wanting to experience the trilogy of grumpiness should help you during your next program or training cycle. But remember that these are stages, not chronic conditions. You should only experience them early in a program or new cycle of training. If you aren't experiencing them at all, it means you're ready to ramp your training up to the next level. But if they persist beyond 4 weeks, you're overdoing it and risk overtraining. You may also experience them each time you transition to a new phase. In this case, though, they should be gone before you move into the next phase.