Suppversity, that great blog that reviews sports related research, has a great short entry today on Kettlebells and Cardio… it’s near the bottom of the article… another subject is discussed at length first.
Here’s the bottom line:
Two similar groups of athletes were given 20 minute workouts designed to improve their “cardio”… either kettlebell snatches done in interval fashion (15 seconds on and 15 seconds rest and presumably changing hands!) or “circuit weight training”, each doing the workout three days per week.
ONLY the kettlebell group showed an increase in “VO2Max” (the measure used to show improved ability to process oxygen as proxy for “endurance”)! Their improved by 6%!
Why the difference?
Dr. Schwartz said years ago that “circuit weight training” was only effective at raising blood pressure. He believed it did NOT actually boost endurance at all! Depending on circuit design, the transition from one isolated muscle group to the next did not meet his requirements for “panaerobic” exercise. Relatively few muscles were involved in many parts of the circuit. Too few to produce improved endurance, though heart rates were increased.
The Kettlebell snatch, on the other hand, meets Dr. Schwartz’ requirement for “panaerobics” because large sets of muscle are used throughout the exercise from neck to toe.
Dr. Schwartz, and Heavyhanders who’ve studied him, would not be surprised at the results.