LAST WINTER, half a year before the Leadville Trail 100 mountain-bike race, Dave Wiens knew he had his work cut out for him. After winning the event six times in a row, from 2003 to 2008, the 46-year-old Gunnison, Colorado, rider finished second behind Lance Armstrong in 2009. To recapture the title, he would have to best the race's strongest field ever, including three-time Tour of California winner Levi Leipheimer and Olympic cross-country riders Jeremy Horgan-Kobelski and Todd Wells. Worse, Wiens barely had time to train. "Between a new job selling medical supplies, my work promoting a local mountain-bike race, my responsibilities for trail advocacy, three active sons, and my wife's schedule as a nurse, I just didn't see how I could be competitive," he recalls.
Rarely do amateur athletes have the luxury of making fitness a top priority. Even genetically gifted regular Joes like Wiens (and Outside's fittest real athletes) have long lists of commitments and little free time. Training is often the first thing on the chopping block. "Time has to rate as one of the biggest constraints for anyone trying to gain or maintain fitness," says Chris Carmichael, founder of Carmichael Training Systems and author of The Time-Crunched Triathlete. "But it takes less time to get fit than most athletes think."
A lot less. Research shows that short, well-targeted, high-intensity workouts can get you as fit as much longer sessions. According to a 2008 study in the American Journal of Physiology, one and a half hours a week of high-intensity interval training will improve arterial structure and function just as much as five hours a week of lower-intensity workouts. And researchers in Denmark showed that runners who added speed training to their regimens while decreasing the overall volume of running by 25 percent logged faster times in a 10K field test after just six to nine weeks. "Most people can spend 50 percent less time working out and still get 80 percent of the benefits," says Lynda Wallenfels, an elite endurance mountain- bike racer and cycling coach.
It's the same with strength training. Numerous studies have shown that you can achieve equivalent gains in strength even if you reduce the frequency of lifting—down to as little as once a week—as long as you fine-tune the workout volume and intensity. "The question is whether you are working hard enough to force the body to adapt," says Bill Pierce, professor of health sciences at Furman University and author of Run Less, Run Faster. "Intensity is the variable that has the greatest impact on improved fitness."
Wiens is proof. In his run-up to Leadville, he rode less mileage than in previous seasons, using interval routines to maximize the impact of his shorter sessions. And while he didn't win (he came in fourth behind Leipheimer and the Olympians), he slashed 12 minutes off his previous best time. "I was really surprised," he says.
The takeaway for the rest of us: "I don't have time" is no longer an acceptable excuse. What follows is your guide to boosting performance on almost any schedule.