There are a lot of online training schedules for all kinds of people available online. I'd ask on the Training & Nutrition group about that.

The first few times I went out, I was totally out of gas. I got stronger as time went on and I also changed my eating habits over the winter because I started xc-skiing again and I had to change what and when I was eating or I'd just completely bonk. Eating and drinking fluids are two things that I've had to become far more disciplined at. I've had to forget about what I could get away with in my teens.

The "Little Engine That Could" or "The Big Engine That Can't" can get a lot stronger but it takes time. ..er more time than that.. must have something to do with age.