i did kickboxing for about 5 years and it is an amazing workout. The trainer that we worked with also had classes of Chinese Gung Fu, which is a lot of flexibility training. If you do join a class, i would suggest not going to every class during the first couple weeks ... otherwise you will be so sore and not want to go. But, once you've done it for about 3-4 weeks, you shouldn't have any trouble.