Boost your fitness and improve your confidence with this challenging interval session. 

Despite some immediate success in his first few years of racing ultramarathons, Dylan Bowman didn’t know much, if anything, about the importance of including faster workouts in his training schedule. Relying on his natural athletic ability—honed from years as a competitive lacrosse player—the tough-minded Bowman finished third in his first crack at the Leadville 100 in 2010, placed second there in 2011 and posted a seventh-place finish at his Western States 100 debut in 2012.

“I didn’t run on a team growing up, so I didn’t even know the meaning of tempo, VO2 max, fartlek and things like that,” Bowman told me earlier this year.

In September of 2013, he began working with Jason Koop, director of coaching for Carmichael Training Systems, who introduced structure and specific intensity into his training routine. The results since have spoken for themselves.

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After winning and setting a course record at the Sean O’Brien 50 Miler in February of 2014, Bowman battled to a podium spot at the Western States 100 few months later, finishing third, and closed out 2014 with a fifth-place finish at The North Face Endurance Challenge Championships on his home trails in the Marin Headlands, north of San Francisco. So far in 2015, the 29-year-old Colorado native has posted the first international wins of his career, taking top honors at New Zealand’s Tarawera 100K in February and winning The North Face 100K Australia on May 16.

One of the secrets to his success? Intervals—and lots of them—of varying lengths and intensity levels, depending on the focus of his current training block.

Bowman’s favorite interval workout is a session of 5 x 10 minutes—preferably uphill—at 80 percent effort with 5 minutes of jogging recovery between reps.

“I do the workout to develop the lactate threshold system,” explains Bowman. “I also do it to improve my climbing ability and overall confidence at an intensity that’s a touch faster than race pace.”

Bowman, who under Koop’s guidance does three focused workouts per week on average, switches between steep and technical sections one day and more gradual, runnable grades the next. He warms up for the workout with 30 minutes of easy running and cools down with some easy jogging.

“During a lactate threshold block, that’s all we work on,” Bowman explains. “We do not vary the intensity or try to develop other systems. Because of this, I’ll usually do a workout very similar to this three days per week on Tuesday, Wednesday and Saturday.”

In the final 3-4 weeks of preparation before a big race, Bowman will do this workout on trails that most closely mimic the terrain he’ll encounter at the event.

“Essentially, I just slot into an intensity that’s slightly faster than 50-mile race pace and try to maintain the same effort for the whole workout,” Bowman says. “Koop stresses the importance of repeatability in these intervals so it’s important to not go too hard in the first couple repeats.”