At mile 20 of the 1993 world championships marathon, mark plaatjes was trailing the leader by more than a minute. Then he kicked into overdrive and overtook Lucketz Swartbooi to win the race. Plaatjes, now 45, credits his surge not only to high mileage and track work, but also to the time he spent building powerful legs. Today, the Boulder, Colorado, coach and physical therapist makes sure his charges strength train two or three times a week. “When you get tired, your strength will pull you through,” he says.
Multiple studies show that regular strength training can improve running economy-how efficiently the body uses oxygen-by as much as eight percent, translating into greater speed and more muscle endurance. And it makes sense for runners to focus on their most important body part. “Strong legs also mean more power on the hills,” says Bob Larsen, who coaches elite marathoner Meb Keflezighi.
Since many runners have a hard enough time squeezing workouts into their busy lives, we asked Plaatjes and Larsen for exercises that deliver maximum benefits in minimal time. Their picks for the most essential moves develop strength where runners need it most-in the core and legs-and correct the natural muscular imbalances caused by running, which can lead to injury and loss of speed. And the exercises can be done at home in about 15 minutes (see “Faster in Five,” next page). “It’s amazing how little it takes-just a few minutes each week,” says Larsen.
Strong legs require a solid foundation. When you run, your abdominal and back muscles fire to stabilize your spine. “Your core gives you a place to drive from,” says Plaatjes. If your core is weak, your legs suffer, so Larsen has his athletes strengthen their core muscles by standing on a flat-bottomed stability trainer and swinging their arms as if they were running. The motion demands that the back and abdominal muscles stabilize the body, just as they do during a run.
You might assume that all your running means you already have strong legs, and indeed, many of the runners that come to Plaatjes’s clinic have strong quads and calves-but their hamstrings are weak by comparison. That’s because when you run, your quadriceps pull your leg forward while your hamstrings control your speed as your foot lands. “The weaker the hamstring is in relation to the quad, the harder it has to work,” says Plaatjes. To correct this imbalance, he favors the hamstring push-up. Unlike a leg curl, the exercise won’t strain tight hamstrings. It uses body weight to tax the muscle eccentrically, which means it builds strength during the lengthening phase. “When you have an imbalance, you overuse certain muscles, which can inflame the tendons,” says Plaatjes. “Eccentric exercises strengthen the connective tissue too, instead of just the muscle.”
Even runners with already strong legs tend to slightly favor one leg, and this can lead to a disparity that can weaken performance and set you up for injury. The solution, says Plaatjes, is to work each leg separately. When you do exercises like a squat using both legs, your stronger side helps your weaker side, reinforcing the discrepancy. Performing single-leg exercises forces the muscles to work on their own, and over time, the imbalances will even out.