Sprint intervals are freaking awesome.
This type of exercise refers to short bursts of maximum-effort exercise sprinkled between longer intervals of rest or low-intensity exercise. They can be done on foot, but are also easily applied to a bike, stationary bike, rower or treadmill.
Compared to just plodding away at a slow-to-moderate pace for your entire workout, sprint intervals have been found to burn more calories, burn more visceral fat, build more muscle and have a bigger positive impact on your mental state, all in less time.
But what's the best way to perform sprint interval training? Although much of the earlier research in this field focused on performing four to six 30-second sprints with 2-3 minutes of recovery in between, recent findings have found much shorter sprint intervals could be even more effective.
Thirty seconds might not sound like a lot, but when you're going pedal to the metal, it can feel like an eternity. The Wingate Test, for example, is a measure of fitness during which the participant pedals as fast as possible on a cycle ergometer (basically a fancy stationary bike) for 30 seconds. It sounds simple, but it's enough to make some NHL prospects vomit. I've also heard of some people trying a 1:1 split for sprint intervals, meaning they'd go all out for 30 seconds, then either rest or go very slowly for the next 30, then repeat that pattern until the session is complete. That sprint interval is way too long—and the rest way too short—for you to actually be working near your max during most of the sprints, thus creating a workout that's missing out on much of what makes sprint intervals so effective.
A recent study published in the journal Kinesiology compared the effects of two different time-matched sprint interval workouts on a cycle ergometer. Here's how it was designed:
- The participants were 11 physically active men.
- Both workouts took a total of 7 minutes and 20 seconds to complete.
- The SIT5s workout utilized 5-second sprints followed by 24 seconds of recovery.
- The SIT20s workout utilized 20-second sprints followed by 120 seconds of recovery.
- In both workouts, participants sprinted for a grand total of 80 seconds, and recovered for a combined six minutes.
- Each participant did both workouts, but on separate days in a fully-rested state.
And here were the results:
- SIT5s workout produced greater heart rates, VO2 maxes, power outputs and total work.
- SIT20s produced higher rate of fatigue and blood lactate accumulation.
- Participants were able to jump higher in a countermovement jump after the SIT5s compared to the SIT20s.
Essentially, the sprint interval that utilized a 5-second sprint interval resulted in more total work and higher intensities, yet a lower rate of fatigue and blood lactate accumulation, compared to the 20-second sprint interval. And remember, the total workout, sprint and recovery times were the same for both groups. "SIT5s was demonstrated to be more efficient as exhibited by greater mechanical responses associated with a higher aerobic activity, when compared to the volume-matched SIT protocol of longer sprints," the authors wrote.
The long and short of it—sprint interval workouts are awesome, but there's a good chance you're currently using sprints that are too long. If your sprints are lasting more than 15-20 seconds, you could probably get superior results using 5- to 10-second sprints with slightly shorter amounts of rest. The simple fact you're sprinting gives you a decided health and wellness edge over most Americans, but smarter programming can help you get even more from your sprint intervals!
Photo Credit: mustafagull/iStock
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