I'm an old guy and being fit for surfing is important. There are some simple things that you can do to keep in reasonable shape. First, make a commitment to do some basic stretches and exercises everyday. My routine starts with arm and shoulder rotations. Followed by knee and back stretches. Finally, I do squats type exercises and push-ups.
The other things I do are fairly simple also. I stretch a lot and recently started using a foam roller. It's helping me regain and maintain flexibility. My diet is vegetarian. I feel healthy and strong as ever. The last thing was giving up beer. I don't miss it anymore. There was a time when I lived an unhealthy life. Now that I'm much older. I'm keeping fit the best ways I know how. I hope this helps anyone looking to have more fun in their sessions. Thanks for your support.