Kettlebells aren't just for strength training anymore.
A new study suggests those big heavy balls might be just as useful for amping up your aerobic fitness as they are at building muscle.
In fact, just four weeks of kettlebell training was enough to improve aerobic capacity by 6 percent in a group of already fit NCAA Division I female soccer players, according to a report published by the Journal of Strength and Conditioning Research.
more
Researchers split the San Jose State University players into two groups. One group did 20-minute, high-intensity kettlebell workouts — 15 seconds of snatches (similar to the one-arm kettlebell swing but the kettlebell is brought overhead) followed by 15 seconds of rest — three times a week. The other group performed multiple free-weight and dynamic body-weight exercises, including ball-and-jump squats, situps and sprints, as part of a continuous circuit program for the same amount of time, also three times a week.
By the end of the four-week study, there was no significant change in the circuit trainers, but the kettlebell snatchers saw a 6 percent jump in their VO2 max, the amount of oxygen the body is able to use at maximum effort.
That's a win for anyone looking for a little variety in their cardio toolkit.
But researchers say the results are good news for those recovering from leg injuries, too.
"Athletes who have sustained a lower extremity injury that warrants little to no impact can perform this protocol as an alternative to maintain cardiovascular fitness," the study authors write. "The kettlebell snatch is a low impact, dynamic exercise that also provides sufficient resistance for muscle strengthening, in addition to enhancing cardiovascular fitness."
The findings build on an April 2014 study that found that 30 minutes of kettlebell training was just as good at improving cardiovascular health as vigorous uphill walking.
