“You can stimulate the same training adaptations that you would get from endurance training through extremely short interval sessions,” Gibala says.
How so? The quick sprints are so intense that they activate your fast-twitch muscle fibres, which are dormant during daily activity and moderate exercise, he says. That means you recruit more muscle in less time, so your workouts can be very brief.
The short bursts of hard work also make your heart stronger and your blood vessels more elastic, so you can deliver more oxygen to your muscles, Gibala says.
There’s one big caveat in this study: The participants were sedentary and overweight. But other research indicates that the benefits would still hold true for fit guys. In 2013, Canadian scientists applied a similar exercise regimen to active men and found that the guys improved their cardiovascular and muscle health.
So does this mean you should slash all your workouts down to 10 minutes? Obviously not, says Gibala.
For one thing, science hasn’t yet proven that sprint interval training is as effective as more time-consuming, moderate exercise in the long run, he says. Most studies on this type of exercise follow participants for a few months at most.
Plus, you obviously need resistance training to build strength and muscle. And if your goal is fat loss, you’ll burn more calories if you extend the workout beyond 10 minutes.
But here’s what you can take away: Incorporating short, very intense sprints into your workout can help take your fitness to the next level, Gibala says.
And more importantly: “If you don’t have 45 minutes to spare, you don’t have to blow off exercise,” he says. “Even if you have as little as 10 minutes, you can get a very high-quality and effective workout. The tradeoff is you gotta go hard.”