If you take your running seriously, you probably work intervals into your training mix every so often in order to work on speed. But did you know that the right type of interval workout can also improve your overall endurance and other performance factors?
Research published over the past decade has found that high intensity interval training helps some runners improve performance parameters like mitochondrial mass and VO2Max better than traditional lower-intensity training. While there are many types of HIIT workouts that can elicit these favorable changes, a team of Danish sport scientists think they’ve found the specific interval workout that combines effectiveness with maximum enjoyment, making it perfect for all types of runners.
Why HIIT Works for Runners
The secret to the effectiveness of a HIIT workout for endurance athletes is the high effort level it demands—requiring a runner to use both the aerobic (or oxidative) and the anaerobic (or glycolytic) energy systems. The same is also true of muscle fibers. Whereas a traditional low-intensity endurance run uses primarily type-1, or slow-twitch muscle fibers, the demands of a HIIT workout require your body to also recruit type-2, or fast-twitch, muscle fibers. Training multiple energy systems and recruiting more motor units can translate to significant improvements in several endurance parameters at the metabolic level.
An Ideal HIIT Workout for Runners?
Sport scientists, running coaches and athletes have all been searching for that “perfect” interval workout—the right combination of work-to-recovery that will elicit the biggest performance gains. In a 2013 meta analysis, a Mayo clinic team concluded that work intervals lasting from three to five minutes were optimal. A small randomized study published two years earlier in the Scandinavian Journal of Medicine and Science in Sports, found that eight minutes of hard work tended to elicit the most favorable outcomes.
While longer work intervals may indeed elicit slightly better gains, the trouble with both of these protocols is that they are, well, hard. No one likes to run at a very high intensity for eight or five or even three minutes. What’s more, because these work/recovery intervals are relatively long, in order to get in the preferred number of sets, the total length of the workout becomes long, as well. In the Scandinavian study, for example, subjects were exercising for a total of 40 minutes, not including warm-up and cool down.
In an effort to create the optimal HIIT training protocol for recreational athletes, the Danish research duo Thomas P. Gunnarsson and Jens Bangsbo came up with a workout they dubbed “10-20-30 Training.” The results of both the original study and a follow-up study published three years later, were impressive. 10-20-30 training not only improved VO2Max and 5K run performance, it also lowered blood pressure and LDL cholesterol levels. Importantly, Gunnarsson’s and Bangsbo’s protocol used recreational runners rather than highly trained athletes, making their studies applicable to a much larger population group than many other studies. The best part about the 10-20-30 training concept, though, is that the entire workout takes only 25-30 minutes, including warm-up and cool-down. This tremendously boosts the adherence factor, making it a workout that most any runner will be likely to stick with over the long-term.