Joel Jamieson of 8 Weeks Out was recently interviewed on the Dangerously Hardcore podcast.
The whole interview is interesting, especially since it's looking at conditioning and heart rate-based training with an eye to bodybuilding. That's an unusual angle, since bodybuilding and figure modeling isn't something you might immediately associated with endurance and conditioning.
During part 2 of the interview, around 22:45 in, Joel rather eloquently points out that the goal of the human body is survival - mostly immediate survival. Building muscle, increasing endurance, decreasing body fat, etc. - the body isn't as concerned with that as you. He then says you need to trick the body into doing these things.
I disagree with the wording in that one part. I don't think "trick" is the right word.
In my opinion, you can't really "trick" the body. Whatever stimulus you think you're giving it, the body understands on a level that you do not what the sum total of stimulus it's getting, the sum total of support your giving it in terms of recovery, food, sleep, etc. You can't trick it, because it "knows" the game and the rules and what's happening in play beyond a level that you consciously do.
Rather, you have to convince it to change. Your body will respond to your demands - I want bigger muscles, I want to lose body fat, I want to run faster for longer. However, it won't do so in the absence of measured, consistent, and appropriate stimulus. Faced with continued stress, it will adapt to it. Your goal is to give it the stress it would need to adapt in that manner.
To get bigger muscles, you need to give your body enough exercise of the right type to provoke a need for larger muscles. You need to feed it enough, and rest it enough, to let that adaptation happen.
However you can't overpower your need for survival. If you simply lift heavy every single day, never resting, your body will eventually break down, not give in and get bigger. But if you lift heavy when you're ready to do so, eat appropriately, and rest sufficiently, and repeat this often, your body will respond. It has to - it will adapt.
I think the term "trick" makes it sound like your can fool your body into doing something. You can't, you just have to give it the need to adapt (training stimulus) and the tools to do so (food, sleep, time off).
But remember what Joel Jamieson says there about survival - your body's goals aren't so easily disregarded, and if you push too hard without recovering, it's going to act in self-preservation. That self-preservation isn't going to get you where you want to go.
Oh, if you're wondering (this comes up on the podcast) - Yuri Gagarin was the first human being in space.