AS KIDS WE LOVED to pile-drive our best friends into the couch, but as adults most of us are far too civilized for the explosive work required to build power. Endurance, strength, flexibility—these are all very sane. But power? Power's for short men in bar fights. Professional lumberjacks. The Rock. Unless you have a score to settle with the bouncer or a hole to open off left tackle, why should you hop, leap, or launch the barbells in the gym like an Olympic weight lifter?

"Because climbing, skiing, or whatever, there's a power component in everything we do," says power-training guru Vern Gambetta, president of Gambetta Sports Training Systems in Sarasota, Florida. "It's the athletic expression of strength." In other words, whether it's outsprinting the peloton or lunging for a climbing hold, sooner or later you'll need power—the measure of how fast and how far you can move an object, often yourself, through space. And like it or not, your steady-as-she-goes strength, flexibility, and endurance work won't give it to you. Which isn't to say those three pillars of fitness are a waste of time. By now, if you've committed to our five-month Shape of Your Life program, you probably feel better than ever. But just because you've got a sustainable plan in place doesn't mean we'll pat you on the back and send you away. Starting today, the program accelerates: You've built your foundation; now it's time to tap your real athleticism by upgrading your power and accentuating its twin attribute, speed.

To back up that promise, we've turned to fitness authorities who aren't typically beloved by outdoor athletes—football coaches, track trainers, and gym teachers. But don't panic—you won't need a Lycra singlet or have to report to the field house. Like the other SYL workouts, this month's regimen can be done in your home gym and at the local park. You'll build power by adding Olympic lifts with dumbbells to your strength routine (think Laird Hamilton, pictured here, not those huge Romanian weight lifters of yore), and ramp up your speed by starting endurance workouts with jumping drills, aka plyometrics. Yeah, yeah—this means your workouts will be longer and more intense, but quit complaining already. In four weeks, you may not pile-drive your workout buddy for old times' sake, but your rekindled athleticism will punish him just the same.