Men have been running since we shared disputed turf with saber-toothed cats. So how come so many of us do it wrong? Plenty of reasons: desk jobs, cars, couches, complacency. The urgency is lacking, the muscles are unused. Few of us have ever felt the need for a lesson.

Prepare to learn and burn. Running incinerates fat like nothing else. And a few tweaks to your technique will have you running faster and longer than any of your distant ancestors.

With all the glory available to world-class runners now, it's no surprise that innovative coaches, sports scientists, and runners themselves search for new techniques to grab an edge.

Take Meb Keflezighi, for instance, the American who won the silver medal in the marathon at the Athens Olympics. He does things-cross-training, plyometrics, bicycling-that the great American marathoner of the '70s, Bill Rodgers, never considered. (And Meb probably wouldn't consider eating Bill's favorite food, pizza with mayo.) The same cutting-edge methods that hone the likes of Keflezighi can help you. It's time to reject conventional wisdom (CW) and hit the roads with newfound wisdom and vigor.

OLD CW: You were born with your stride; make the most of it.

NEW CW: Change your stride for the better.

Elite runners move more efficiently than the rest of us, using less energy at any speed. An efficient stride is comfortable and reduces risk of injury. Until recently, running coaches and biomechanics experts believed that individual stride patterns were too hardwired for average runners to learn to run more like the elites.

The latest science shows that anyone can change his stride for the better, with a little patience and discipline. But do it gradually, one modification at a time, and practice each single change with every step until it becomes automatic. Here are the three best efficiency-boosting stride changes you can make.

1. Shorten your stride. About eight in 10 recreational runners overstride, according to Alan Hreljac, Ph.D., a professor of biomechanics at California State University at Sacramento. This creates a thudding, braking effect. To correct it, lean your entire body slightly forward as you run. Your feet will land a little closer to your body.

2. Defy gravity. Reduce the amount of time each foot is on the ground. While you run, think about pulling your leg backward just as your foot makes contact with the ground. A typical plodder lands, stands, and then thrusts backward.

3. Bounce less. Imagine a low ceiling 2 inches above your head. It'll keep your gait smooth and efficient. You don't want up-and-down; you want forward.

OLD CW: Speed is for sprinters.

NEW CW: Speed training helps everyone.

Think back on your past week of running. How much of it was at a brisk, saber-tooth-eluding clip? Today's top runners do as much as 20 percent of their training at speeds faster than race pace. This conditions the fast-twitch muscle fibers that are seldom recruited during slower running. It also maximizes aerobic capacity (the rate at which your muscles use oxygen) and increases stride power and efficiency. Speed training also makes you ripped.

You burn more calories, because, simply, it takes more energy to run hard. And fast running is the perfect companion to strength training-both work the fast-twitch muscle fibers. Here's a speed-training format to try.

The Ladder
Do this workout at a running track.

1. Warm up with 5 to 10 minutes of easy jogging, followed by stretches for the hamstrings and calves.

2. Run one lap hard, then jog one lap.

3. Run two laps hard and jog one.

4. Run three laps hard and jog one.

5. Optional: Run four laps hard.

6. Cool down with 5 to 10 minutes of easy jogging.

OLD CW: Run up hills, then jog back down.

NEW CW: Run down hills, then jog back up.

Downhill running is integral to the training of elite distance runners. Running downhill increases stress on your legs, which makes them better able to handle impact as long as you don't overdo it. Running downhill can help you go faster, because your muscles will grow accustomed to the quicker stride required.

Once or twice a week, after completing an easy run, do four to six relaxed downhill sprints (not on a steep hill, just an easy grade) lasting about 20 seconds apiece. Recover between sprints by jogging slowly back up the hill.

OLD CW: Strength makes you faster.

NEW CW: Explosive power makes you faster.

You know by now that cross-training helps your running by strengthening the rest of your body while giving your running muscles and joints a break. Next step: Add plyometrics, or jumping drills, to your cross-training. You'll improve your efficiency and power.

Researchers at the University of Jyväskylä, in Finland, found that runners who replaced a third of their weekly running with plyometrics improved their 5-K race times by roughly 3 percent, while a control group saw no improvement. So if you run a 25-minute 5-K, you can shave a minute off your time by running less. Try these plyometric exercises.

Split Squat Leap
Stand with your left foot half a step ahead of your right foot, your hands at your sides. Lower yourself until your back knee is about an inch off the floor, then leap as high off the floor as you can. (Drive your arms up above you to help propel your body upward.) While airborne, reverse the position of your feet so that when you land, your right foot is a half step ahead of your left. Immediately lower yourself into another deep squat. Complete 16 to 24 jumps (eight to 12 in each position).

Single-Leg Box Jump
Balance on your left foot facing a sturdy platform (such as an exercise step) that's 10 to 18 inches high. Leap onto the platform, landing on your left foot, and immediately jump back down to the floor on the same foot. Do 10 to 20 repetitions, then switch to your right foot and repeat.

OLD CW: Make every run count.

NEW CW: Use the "hard-easy" rule.

Use a 1-to-10 scale to rate how challenging your workouts are. Most runners hover around a 5 (not hard, not easy) day after day after day. Today's top runners avoid this gray zone by doing runs that are either truly challenging (8 and above) or very easy (3 and below).

The reason? The biggest fitness gains come from the hardest workouts, but you can't take yourself to the limit every time you lace up your Asics. Follow the hard-easy rule and you can achieve better results with the same total amount of training you're doing now. You'll be able to push harder on some days by allowing your body to recover on others. This will help you avoid overtraining, and you won't tire from a repetitive routine.

Let's say you run four times a week at level 5. This week, try doing two level-8 runs (one long run and one speed session) and two level 2's (short, easy runs). Either approach adds up to 20 effort "points." Stick with the hard-easy schedule for a couple of months and check your race times. Your numbers should be smaller.

OLD CW: Stick to your plan.

NEW CW: Free your mind, man.

Too many runners treat their training plans as gospel. But a growing number are learning the benefits of "training opportunistically." Here's how it works.

You need to do your most challenging runs on days when you feel good. But you never know how you're going to feel until you start running. Forcing yourself to crank out hard runs on predetermined days means you'll inevitably turn in some subpar performances and won't benefit as much as you could.

Begin each workout day with the option of either a Plan A (challenging) or a Plan B (easy) run. If you're headed out for a Plan A effort but feel flat during your warmup, switch to Plan B: an easy run. And if you find you have plenty in the tank on a B day, gear up to an A. Of course, the catch is the temptation to declare all days Plan B's. Make the switch only if you feel truly lousy. Otherwise, grind through it.

This takes a little discipline. And that's one bit of conventional wisdom that will never change.

Matt Fitzgerald is the author of The Cutting Edge Runner .

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