I think I would have a heart attack doing those just by u guys talking abou it.
I have hard enough time doing the drills in my kickboxing class and I thought I was in shape WRONG.
We do 2,2min rounds of jump roping with 30 second rests,2 rounds of shadow boxing for 2 mins each. Then we do 3 minute round of punches/kicks then do 1min abs or some other form of cardio/strengthening rinse and repeat for 45 mins or so..I'm freaking tired after the jump ropes
I'm actually enjoying doing kickboxing just wish I would of done it years ago having hard time with my foot work...