Omgosh...if you are out of shape or trying to get back into the groove of things don't undermine doing a light workout. My roommate and I went to a one-on-one session with a kickboxing instructor and let me tell you...I'm sore as crape lol. It was only 45 minutes but I was sweatinggggg, honey lol. He made us do 20 pushups and my upperbody must have been pushing because that's where I am mostly sore. He also made us run in place while he was talking. That means NO BREAKS. Lol. He did let us get some water because it was our first time. I plan to keep this up though. I had a great time and got a good workout in!
So get out there and just do something...anything lol