I can't tell from the posts whether kb exercises are cardio or muscle toning or both. Are different WOs geared different ways? And when I read about "swinging" the kbs my lower back starts to hurt just hearing about it. Do all the WOs involve "swinging"? Some illumination from the educated crowd, please?
I think KB's are an overall workout : they work strength (strength endurance), cardio and flexibility at the same time. Very efficient!
The swing can actually help improve muscle endurance of the lower back, and help with back problems if done correctly (and if there are no contraindications). Stuart McGill (sp?) is a back expert (who has written some rather technical books on the subject) and according to him, most people are lacking in lower back endurance, even those who have good lower back strength, and it is strength endurance that is most important for avoiding back injuries and pain.
The power of the swing comes from a hip snap (sounds a bit violent, but just think of a porno hip thrust...that's what it looks like on some people, like Mike Mahler!). The lower back is involved, but should be slightly arched to engage the muscles on the down swing.
When/if my lower back feels like it has had enough, that's the end of my workout session (I felt that way near the end of Lauren Brooks' workout--I haven't been doing KB's regularly for a while
--so I stopped).
Most workouts are total-body workouts. But some are more geared towards different goals. This Steve Cotter DVD
http://www.amazon.com/Kettlebell-St...ef=sr_1_2?ie=UTF8&s=dvd&qid=1225720918&sr=8-2 has workouts focusing on upper body, lower body, core and cardio (Though there are not 15 'workouts' as advertised. There are 15 'segments,' including the "introduction' to each workout and the separate warm-ups. The actual complete workouts are 1) upper body, 2) lower body, 3) cardio/circuit, 4-6) 3, 10-minute ab/core workouts, 7-8) 2 core/circuit workouts.