Widen Your Horizon
What defines endurance? How about running six-minute miles for an entire marathon with a heart rate of 155—a number most people hit on a light jog? That's what 34-year-old Tim DeBoom, two-time Ironman world champion, can do. The secret resides in a body that's become hyperefficient at burning oxygen to power athletic activity and equally efficient at removing stride-slowing lactic acid. The fuel efficiency was cultivated over seven years of consistent, focused training; the superior lactic flush comes from a few weeks of race-pace work prior to competition.
Ed McNeely, a strength-conditioning coach at Rowing Canada who has worked with 31 Olympic athletes in 17 different sports, explains the success of DeBoom's approach. "You can't gain endurance by training at your limit all the time," he says. "You'll exhaust yourself before your body creates the mechanisms needed to boost its efficiency."
Ideally, says McNeely, you should develop your aerobic foundation first and save speed work for last. "You need to spend at least six weeks exercising four times a week to build a base," says McNeely. Then, like DeBoom, you'll go faster and farther each year.
To build bonk-proof endurance, plan your training season in the following phases.
Base building: This phase should take up the first four-fifths of your training schedule, whether it's for an active summer season or a big event, like a marathon. The pace for building base is one that allows you to talk during a workout. Four times a week, aim for light but sustained workouts lasting at least one hour for runners, rowers, and swimmers, and two hours for cyclists.
Threshold training: Spend the last fifth of your conditioning schedule folding in high-intensity efforts at your lactic-acid threshold (LT), "the point where lactic-acid production exceeds its removal," says McNeely. That calls for up to, but no more than, six weeks of running for one hour, working in five- to ten-minute intervals. Start with ten minutes of recovery between each interval; by week six, recovery time should shrink to five minutes. By pushing into a high-intensity zone, you'll gradually knock back your breaking point.
"By now, I know my threshold by feel," says DeBoom, "and I'll hover right below it during a race."
Toolbox: For a total-body endurance workout with zero wear and tear, hop on the Concept2 Model D indoor rower. It'll ramp up your heart rate, and strengthen legs, arms, shoulders, back, stomach, and butt. ($850; 800-245-5676, www.concept2.com)