LESS IS MORE
During my time helping people learn about sports training, one of the most difficult things to get people to buy into is the low volume of training that my programs usually call for. Many people have a "more is better" mentality. They want to go for runs in the morning, play their sport in the afternoon, and lift at night. Every day. It's important to realize that training to be an athlete is quite different from training to just be in shape. For that purpose, doing more is quite effective. Fitness programs like P90X and Insanity demonstrate this very well. Believe it or not, if you exercise very hard 6 days a week, you can get in good shape. There's not too much genius behind that. Burning calories is all you need to do. Your body does not recover from one workout in order to burn calories the next. But to become a better athlete, you need to develop strong muscles and tendons, springlike muscles and tendons, and an explosive nervous system. These things require adaptation by the body, adaptation that takes time. In my programs, I use 2 or 3 workouts a week, I recommend at least a week off after a phase, and I only recommend doing three phases in succession. The primary purpose of that is to maintain or regain your body's ability to recover. The best term I've heard for this is adaptation energy. As far as I know, the specific physiology of this idea is not figured out. There is no compartment in your body that fills up with this special energy. What we know is that hard training wears the body down in some way that reduces it's ability to continue adapting. This is why recovery is absolutely critical to sports training.
One important thing to do as you start training is figure out what kind of recovery ability you have. Genetics, nutrition, lifestyle, and especially age can all affect how well and how fast you recover from training. For example, a kid in puberty who starts lifting can make ridiculous strength gains (see the About Me page) that a full grown adult could never hope to make without the use of steroids. At the same time though, as you go through years of lifting and other training, your body should become more capable of adapting if the training is consistent. Many of the elite Olympic lifters and strong men today lift nearly every day. There are even stories of athletes lifting three times a day and maxing out on a couple lifts in every work out. Those same people always end up testing positive for a banned substance. Another example. I worked third shift in a warehouse for several months. The lack of sleep has made it nearly impossible to make training improvements. I had to adjust my training accordingly, and even so I ended gaining as much weight as I added to my max squat. The point is the human body can possess a wide range of adaptive capability. The training I recommend is intended for a typical person. Generally people tend to overestimate how much training they should do, and the "Less is More" lesson needs to be learned.
Realize that no one else can know your body as well you can. You need to become the most qualified person to decide how much training you should do. All I can do is write training based on what I've learned and based on my experience. But maybe you play basketball four times a week. Maybe you're 40 years old. Maybe you work third shift. All those things affect how well you will recover from training. If you start a high volume lifting phase, and you're weaker in week 3 than week 1, cut out the middle workout. Or space the workouts out more. Do something different. Don't just run yourself into the ground. Those are the kinds of decisions that some guy with a website can't make for you.