Muscles are dumb. They only know two simple actions-stretching out and tensing up-and they can't tell what they're being stretched or tensed by any better than you can tell when your girlfriend gets her nails done (until she tells you). In your muscles' case, that's a good thing, because it means they'll respond-and grow-regardless of what type of stimuli you throw at them. Put simply, as far as your muscles are concerned, the kind of resistance you use while working out doesn't matter. It can come in the form of a barbell, a dumbbell, a cable station, or your own body weight. (Everything, that is, except a machine. Exercises in which your body is free to move through its natural planes of motion always work your muscles harder than a typical machine-assisted lift.) That said, it is possible to make awesome muscle gains without fancy equipment- or even a real gym-simply by using the weight of your own body.

I'll be blunt: A guy shouldn't even attempt to pick up a dumbbell until he can handle his own body weight. After all, if the load you're already carrying is too heavy, there's no sense in making it tougher. The problem is, most guys don't realize how tough body-weight-only training really is. I'm continually amazed by how many people I meet who can bench press a very heavy load but can't complete 10 good pushups. There are a number of reasons: First, the bench press is a more stable exercise (your body rests on a bench), so you automatically have the support you need to hoist heavier weights. Furthermore, when you bench, your central nervous system only needs to coordinate the efforts of your chest, shoulders, and triceps. The pushup, on the other hand, puts you in a more awkward position (balancing above the floor), and it requires work from your abs, lower back, rotator cuffs, and legs just to stabilize each rep. So basically, the pushup is a tougher exercise.

But by mastering the pushup, you automatically set yourself up for big bench-press gains (even if you're already the strongest MFer in the gym). Forgoing it for more of the same, however, can be hazardous: Benching regularly without training the auxiliary muscles the pushup hits can cause some major weak links in your bench-press chain, which, if not addressed, will lead to quick plateaus in the amount you can lift, as well as injuries (usually to the rotator cuff ). If your goal is fat loss or improved athletic performance, there are even more compelling reasons to revisit the pushup in your routine. In addition to burning more calories than bench presses do, pushups are a much more functional exercise, helping to prepare you for a number of sports. Ask yourself this: What good is putting up 250 lbs on the bench if you can't apply that strength in the heat of battle?

In my opinion, unless you can do 20 pushups with ease, you have no business doing a bench press. In fact, at my facility-which is home to five worldchampion lifters and professionals from every sport-everyone begins their training with body-weight exercises. You have to earn the right to lift weights.

Let's say you can pass my pushup test- that doesn't mean you're above bodyweight training. Gymnasts train with their own weight almost exclusively and often have better bodies and strength levels than your average bodybuilder or weightlifter. That's especially incredible when you bear in mind that their sport isn't at all based on body aesthetics or max lifts. According to Nick Grantham, C.S.C.S., former conditioning coach for the Great Britain Olympic Gymnastics team, after years of body-weight training alone, the majority of male gymnasts are able to bench press double their body weight the first time they ever slide under a bar. If that doesn't prove the efficacy of body-weight training, nothing will.