I am a big believer in leg strength training rides. I learned the importance of leg strength on my first trip to the mountains for some training rides. I had always concentrated my training on aerobic endurance with lower resistance and high cadence. But I found out that in order to be able to rely on your aerobic endurance to get you up hills you have to have sufficient gearing for the given climbs. In other words, put on the right climbs, you may eventually run out of gears to maintain a high cadence. At that point all you have left is your leg strength to grind your way up.

You said that at your age you are too old to get back to your high school weight. Out of curiosity, how old are you and how over weight do you think you are? Losing weight will help tremendously with your climbing ability. I am 40 and over the last few years, I have dropped my weight to below my high school weight. I still have some weight I could lose and probably will over the next couple of months. Losing weight will probably be more about motivation than age. I would think if you're active enough to ride regularly you are probably active enough to facilitate weight loss.