They are great for core strength and all around strength really! They are just so versitle and have so many possibilities, a really great workout tool for strength or conditioning or fat loss or whatever you want. I started with a 15lb KB to try and get the hang of the various movements, some of them are a bit tricky to get used to, so I used the 15lb one to pratice my form with it then I got this 35lb one just recently. I had the 35lb one for a couple months but havent used it as much as I would like to, in the future I would like to add it in on cardio days or end workouts with a KB circuit for fat loss. There are tons of links with instructional videos and sample programs online. I have a couple of ebooks on the kettlebook that might be usefull if your interested. I would get a small weight one at first and then just look for videos on youtube of technique and form and pratice before you jump into heavier ones.