There are many claims regarding the number of calories burned during a kettlebell interval class.
A study was conducted by the American Council on Exercise and Dr. John Porcari, leader of the study, said this. “So they were burning at least 20.2 calories per minute, which is off the charts. That’s equivalent to running a 6-minute mile pace. The only other thing I could find that burns that many calories is crosscountry skiing up hill at a fast pace.” So in a 30 minute interval class (3 min sets with 1 min rest), that equates to 424.2 calories! But isn't the immediate calories used during a session doesn't end when the session is finished-the calories continue to burn long afterwards due to an increase in metabolism.
You can read the extract at: http://www.acefitness.org/getfit/studies/kettlebells012010.pdf
By the way, the press on diagram 7-form could be better! The first person who emails the studio with how the form could be improved will receive an organic cotton retro yoga T Shirt.