Been doing kettlebells for about 4 years after 35 years as a serious runner.Found Kettlercise about 3 years ago and have been doing their DVD's since. The new Lean in 14 DVD complexes are something else. Not only do they exercises and train your muscles but the complexes train your brain. When I first started doing them I ended up like a reef knot at the end but now I am nearly there. It also surprises me that I am better coordinated one one side more that the other. It might not be a problem to younger people but as you are getting older your coordination and balance suffers. I am 69 in a couple of months, so what I am saying is that if there are older people reading the forum, keep going and do the routines at your speed and to the best of your ability.