Glutamine is going to help to a certain level for sure; Benefits being immune system function, helpng to prevent muscle breakdown during strenuous levels of exercise, protein synthesis, and improved recovery w/ muscle soreness. BCAAs are really great to also incorporate as well- both pre and post training. You may find yourself needing to be more diligent in post-exercise stretching as this can really reduce soreness and help keep your muscles in shape.

A great supplement for overall mens health and specifically those over 35 is the OptiMale RX from Dr. Richard Cohen  (helps restore key hormone levels naturally).  I always recc. this to any guy who wants to see marked improvements in physical well-being and performance.

Creatine powder (2-3 grams) before you run may be something else to look at- a proven great supplement which assists in both aerobic activity and in weight training. Many different brands out there to choose from- It can be stacked w/ your glutamine powder as well...

Best of luck.