I'm 62 and just waiting to get my recently broken arm loosened up a bit more so I can get back in the water and continue my tech training. I'd recommend taking the Nitrox course for the review on gas laws, etc., as much as anything else. Using it won't hurt, it might help. The fatigue issue is being debated, but since fatigue is often mentioned as being a symptom of sub-clinical DCS, there might be something to it. In any event, this is a good excuse to get back in the gym and get into better shape, which will be good in lots of ways.