I'm a 53 year old Masters lifter and I'll weigh in with my observations, for what they're worth. Due to a number of factors, I believe training as you get older becomes more individualized. Let me explain. I'm always interested in reading about training methods of other masters lifters. I've noted some train near max, up to 5 - 6 times a week, others 2 - 3 times a week never exceeding 80 - 85% of max. There is no one right way to get results. Often times these people have found what works for them, and that is your goal too. Find what works for you. This isn't always easy to do and often involves a lot of trail and error. Just because someone else your age can train 5x a week at a high intensity, doesn't mean you can. Know what your body can handle. I've found that the worst thing is going too hard for too long and getting injured. That often results in missed training time and losing much of your hard fought gains. Time missed to injuries when you're young might be a couple of days, whereas, the same injury in your 40 - 50+, might take several weeks. In this regard, getting old sucks. Having said this, your body will adapt over time to heavier work loads. Just because you're having trouble recovering now from training 3x a week, doesn't mean you won't be able to get there at current intensities. My suggestion would be to keep training at 3 days a week but to dial the intensity back a little on one or two of the days, until your body adapts and then add a little more intensity. When in doubt, always do less. It's better to leave a workout with something left in the tank, than to have pushed it too far. Good luck.