Zumba is great! I'm the most unfit person ever, get out of breath going up the stairs at home lol.
I was kind of roped into this as it was an ex work colleague who is going Zumba intruction part time and i was worried about going as i'm 15 stones, knees and ankles hurt along with my back ( nothing major just due to the weight) but you can go at your own pace and some steps you can do at a gentler pace or be more energetic, i felt great. My class was £5 per session, and not to convenient to get to and i have brought a DVD of Amazon which i am using. Don't regret it one bit! Just make sure you start easy and week on week put that extra bit in and warm up and cool down.