Get Your Legs into Alignment
We weren't built for swimming, nor, unfortunately, were we built for cycling. "We're bipedal," says Andy Pruitt, a former competitive cyclist and current clinical director of the Boulder Center for Sports Medicine, a sort of Olympic Training Center for non-Olympians where Pruitt analyzes cycling biomechanics using three-dimensional computer modeling. "The foot is designed for ambulation involving the whole foot; our stride goes heel-strike, mid-stance, ball. But the cycling stroke takes place in the balls of the foot exclusively." Further complicating matters is forefoot varus, common to 85 percent of cyclists. Forefoot varus means that the inner ball of your foot is elevated above the rest of the foot by a couple of millimeters, resulting in a knock-kneed pedal stroke (as you push down, you're essentially standing on a tilted platform, which throws the other joints out of alignment). In some cases, this can lead to overuse injuries for novice cyclists, but it's also a real biomechanical bugaboo. Driving your pedal downward on a knee angled inward uses more energy than necessary to spin your pedals. The deviation may be minor, but the loss of efficiency can be significant. Your goal, then, is to train your muscles to guide your legs in a near-perfect vertical plane. "Think about a piston in a car," says Pruitt. "Pushing down in a straight line is far more efficient than in an arc."
There are two direct routes to achieving vertical knee-hip alignment: Pick up a pair of Pruitt-designed alignment-correcting Body Geometry Pro cycling shoes from Specialized (see "Full Tilt," right), or master the following exercise. Two to three times a week for three weeks, get to a leg-press machine and load it up with the equivalent of your body weight. Center your knees visually over the second toe (they'll want to veer inside) and do three to four sets of ten to 15 leg presses on each leg. Focus on controlled, steady movements. Viewed from the front, your hip joint, the middle of your knee, and your second toe should be in a straight line. After three weeks, increase the weight slightly and lower the reps, continuing to focus on form. By then you'll be training for a variety of riding conditions. "More weight impacts your climbing muscles," says Pruitt. "In theory, once the weight gets heavier you're riding uphill or into a headwind."
Spin in Circles
Mountain-biking coach and former Olympian Ann Trombley says too many of us are mashers, not spinners. She's talking about our pedal strokes. Specifically, instead of mashing--pushing on the pedals through the downstroke only--she applies force to each leg throughout the pedal rotation: Push down in the vertical piston motion described in the road-biking section, "scrape" the shoe (as if to wipe mud off the sole) at the bottom of the stroke, actively lift the leg on the upstroke, and push your foot forward at the top of the rotation. While it's beneficial in any kind of cycling, a circular pedal stroke can be especially helpful off-road. "In order to climb hills with loose rocks you have to be really smooth," she says. "You can't be pounding. You want equal pressure all the way around your stroke."
The best way to develop a solid circular stroke--which works in harmony with the vertical alignment discussed in the road-biking section--is to practice one-legged pedaling. Trombley places one foot on her water-bottle cage (your rear axle also works well--just don't kick loose your quick-release) for 30 seconds, rests for a minute, and then switches feet. Warm up with easy spinning for 15 minutes on flat, paved road, working up to a minute on, a minute off, alternating legs, for 20 minutes before you hit the trail. It's harder than it sounds, so be sure to save a little juice for your actual ride.
Chances are you're among the 85 percent of the population with a natural forefoot varus. (Check this by kneeling in a chair with your legs together. Have a friend look down at your feet, which should be hanging in a neutral position. Does the inside ball of your foot rest slightly above the outside? That's forefoot varus.) If so, consider investing in Body Geometry Pro cycling shoes by Specialized. Codeveloped by biomechanics expert Andy Pruitt, the shoes feature a built-in wedge that slightly elevates the outside of the foot. The adjusted position keeps the foot from rocking on the pedal and allows an optimal transfer of energy to each stroke. ($150; 408-779-6229; www.specialized.com.)