For eons, people have dreamed that we might one day find some kind of fountain of youth. The scientists at the Mayo Clinic--who don't exactly talk in that kind of mythical language--might well have come up with the next best thing.

Short version: Researchers say they've figured out what kind of exercise you should do, and when, to "reverse [the] aging process in adults," as the Mayo Clinic put it in a press release.

That's a pretty amazing claim, so let's get right to the details.

High-intensity interval training

The researchers recruited hundreds of adults for the study, and whittled them down to a select 72, divided in two targeted age groups: 18- to 30-year-olds, and 65- to 80-year-olds. Then they had different members of each cohort engage in various kinds of exercise regimens over 12 weeks, and they tracked the metabolic and molecular changes that members of each group experienced.

Participants focused on three types of exercise regimens:

  • Some focused on high-intensity interval training (workouts that alternate short periods of intense anaerobic exercise with less intense recovery periods).
  • Others focused on resistance training (activity focused more on strength, working against resistance from weights, gravity, elastics, or your body weight, etc.).
  • Finally, some participated in a combination of both high-intensity interval training and resistance training.

Of course, the researchers emphasized that any kind of exercise was beneficial. However, they found that high-intensity interval training, especially when done by members of the older cohort, "reversed some manifestations of aging in the body's protein function," according to the report.

In laymen's terms--which are frankly more exciting--high-intensity interval training "significantly enhanced the cellular machinery responsible for making new proteins. That contributes to protein synthesis, thus reversing a major adverse effect of aging."

Reverse the effects of aging

So while it's not time travel, and not quite the fountain of youth, perhaps the study is fascinating because it suggests that people can use exercise to manipulate their cells and counteract aging.

There were other benefits as well, including better cardio respiratory health and muscle mass; insulin sensitivity improved no matter what kind of exercise the participants did.

As the senior researcher on the study, K. Sreekumaran Nair, emphasized:

"We encourage everyone to exercise regularly, but the take-home message for aging adults is that supervised high-intensity training is probably best, because, both metabolically and at the molecular level, it confers the most benefits."

Also--and you'd expect this--muscle strength increased "only modestly with high-intensity interval training but occurred with resistance training alone or when added to the aerobic training."