Welcome to the forum red90. Living life at a slower pace than you would like at your age must be frustrating, it is even if you're older. I think you can spend some of the time developing skills you might not have otherwise considered. I'm thinking of practical things like crafts, woodworking, pottery or similar, things that aren't too taxing on the brain but absorbing. I would totally avoid contact sport as and just walk and cycle or swim for exercise. Taking things easy you will recover quicker.