Is male sexual stamina linked to fitness?

Actually, according to some research, exercising migh actually reduce sexual urges in men, while it tends to increase it in women.

If you are talking about physical stamina, as in the energy you have and how long you can "go on", then yes, exercise will increase your general phisical fittness, and stamina.

However, if you are talking about your libido, or sexual urges, then exercise has not much to do with it phisically. Psychologically, having a better body might give you more confidence, and that might result in more confidence in the bedroom as well.

I would say, if you are recovering from a car accident, and operations, then your body is still healing. The body is a very smart machine; it will conserve energy and prioritize resources used in the order of their importance. Therefore, it might reduce the amounts of hormones responsible for sexual urges and use the energy for healing.

Exercising, and being fit, will benefit you nevertheless, and contribute to your general health, which in turn will no doubt have a great impact on your sex life!

Being 29 by the way is by no way the end of a man's prime..on the contrary. You have many, many, many more years of great sex to come!