When looking at the exercise science research out there, there’s no question that high intensity interval training, or HIIT, seems to be the darling of the fitness world: Study after study shows health benefits that range from lowering your risk of cancer to boosting your brain function.

Add that to the research showing that just small bursts of intense physical activity like sprints can supercharge your weight loss—as little as 8 seconds to 30 seconds of all-out effort at a time, according to one review of the literature out there—and it’s no surprise that more and more people are adding intervals to their training.

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But let’s be honest: Have you ever wondered what the real-world implications of this actually are? How much can mere minutes of exercise per week really help if you are trying to lose weight?

For David Paul Kirkpatrick, former president of Paramount Pictures, the answer was simple: a lot.

Kirkpatrick, not one to shy away from a goal—at the age of 66, he logged 100,000 steps in a day—found a sprinting routine that helped him get his fitness back. And he lost some significant weight in the process.

Years ago, when the 68-year-old lived in Santa Monica, California, as a young studio executive, he ran on the beach every morning, but did not stick with that habit. As a result, as the years went by and his schedule became even more packed, his weight creeped up along with it.

As Kirkpatrick told Runner’s World, he has a body type that tends to put on extra weight easily. When he reached his heaviest—92.5kg—and found his fitness level declining, he knew he had to do something about it.

He wanted something that was easy to stick to—and fun enough that he would want to exercise regularly.

A chance conversation last year with a friend from Chicago gave him just the impetus he needed: His friend suggested that Kirkpatrick run “like I was five years old again.”

So he did. Chasing a soccer ball is what helped him get back into it, he wrote in an article for Medium.

“It was like a switch went on. My body went into reboot. It was amazing,” he told Runner’s World.

Now, Kirkpatrick follows his sprinting regimen three times a week—taking one rest day between each interval set. He does seven sprints over a seven-minute period, sprinting for as long as he can stand it, which is about 15 seconds, and then recovering for 45 before doing it all over again.

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And, his sprinting plan is actually in line with research. A recent meta-analysis found that people who engaged in sprint-interval training (exercise equal to or higher than your VO2 max) lost 29 percent more bodyweight than those who engaged in continuous moderate-intensity exercise. So, it makes sense that adding chasing after a soccer ball to his routine would help boost his weight loss.

Plus, a study published in the ACSM Health and Fitness Journal laid out the benefits of a 7-minute workout, using a mix of bodyweight and high-intensity interval training. While this method incorporates full-body moves, the high-intensity nature of Kirkpatrick’s seven minutes of sprinting follows the same principle.

And though he didn’t set out with a weight loss goal in mind, adding sprinting to his weekly routine, combined with a diet change, has led him to a 20-kg weight loss. (He cut out low-quality carbs like crackers and cookies, focusing instead on whole, plant-based foods. He gets the majority of his protein from chicken, fish, and nuts.)

Kirkpatrick also makes sure to boost physical activity throughout the day, even when he’s not sprinting. He calls himself a compulsive step counter, and makes sure to get 10,000 steps in each day.

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That, combined with sprinting and diet change, has helped him reach 72.5 kgs—the weight he was in high school.

“The leanness is surely from sprinting. I never had that with running on the beach in Santa Monica,” he says.

While Kirkpatrick’s 21 minutes of weekly sprints was not a magic bullet—he combined it with diet changes and increased physical activity throughout the day—it does show the benefits of how just a little bit of sweat can yield big results. So go ahead, listen to the research: Add some intervals to your routine, and your body just may thank you, too.

This article originally appeared on runnersworld.com

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