You commented on one of my blogs about a 'resistaball' class I'm taking at the YMCA and asked me to let you know what I thought...
I really like it, it's a great workout! We don't use the ball 100% of the class, but for a large portion of it. It seems as though we are doing different exercises every week, so I don't get bored and use different muscles than I would at home (my shoulders look AWESOME right now!).
I think I've attended 3 of these classes now (I go to some other toning and also cardio classes, too). You work all the major muscle groups, using the ball, free weights, a medicine ball, a floor mat, etc. It's been really good so far. If you have the opportunity, I'd definitely try it out. Have fun! 2902 days ago