Push-up intensity

It's no easy matter staying in shape when the whole world conspires to keep you looking like Porky Pig's brother.

Between frequent business trips out of town; brain-draining, dispiriting 60-hour workweeks; and weekends wasted watching Hope Floats with the girlfriend, you're lucky your body hasn't turned you in to the government's fitness czar on grounds of neglect. Leading a busy lifestyle usually means placing all your hard-earned muscle on the sacrificial altar of "not enough time." However, keeping in shape doesn't have to be so time-consuming, nor inconvenient. No matter how complex your life may get, you already have all the equipment you'll need--well within arm's reach--for staying fit.

The classic push-up has survived the ages of iron, Nautilus and Cybex because of its easy access, but convenience isn't the only reason this timeless exercise is still relevant to the guy intent on building a better physique.

"No single movement simultaneously strengthens the chest, deltoids, lower back, and triceps quite as efficiently as the push-up," says Kurt Brungardt, author of The Complete Book of Shoulders and Arms. Fear of embedding your teeth into the floor forces you to spend equal time lowering your body as you do raising it back up, a concentrated effort you may not often allow when using free weights. It's this controlled pace that works muscles through three types of muscle-building resistance (concentric, eccentric and isometric) while teaching Push-ups offer many other perks that you may be unaware of.

* "Being able to perform beyond 12 repetitions improves muscular endurance within the upper body, an area that most men typically neglect," says trainer Fred McDaniel, co-founder of the Human Performance Center in Santa Fe, N.M.

* Push-ups can also improve your reaction time by training your proprioceptive fibers (microscopic nerves responsible for keeping your body balanced) to respond more quickly. "Just holding yourself in a push-up position causes these nerves to fire continuously just to keep your body from tipping over," says McDaniel.

* Finally, because push-ups are a high-rep exercise, they help increase blood flow within the torso and arms, which flushes out lactic acid from muscles, lessening any postworkout soreness you may have as a result of your weightlifting routine.

There's only one catch: With the exception of when you're having sex, going up and down all the time can get boring pretty fast if you don't jazz things up, for both your muscles and your mind. Mixing up the workouts keeps the muscles responding to the stimulation.

Accordingly, MEN'S FITNESS has created three separate workouts, each designed to make things more interesting as you take your push-up routine to the next level. Whether you perform these moves for convenience, for sports training or to improve your physique, your body is never far from the full-body treatment it deserves.

* Before you begin: For all nine exercises, take at least two seconds to lower yourself down and two seconds to press yourself back up. "The slower you move, the more effort you'll place on the muscles you're looking to strengthen and shape,"