I'm only 47, but I have a couple guiding principles that have been helpful so far. The first is to stay flexible. I've been a runner, hiker, bicyclist, climber,

I'm only 47, but I have a couple guiding principles that have been helpful so far. The first is to stay flexible. I've been a runner, hiker, bicyclist, climber, kayaker etc all my life. I've gone in and out of shape depending on what's happening in my life. The only times I've really struggled physically have been when I let my muscles get really tight. Three weeks of steady stretching has done more than anything to make me feel better physically. If I can't run for some reason, maintaining flexibility makes it much easier to pick up any of these activities again. The second is to find some new, significant challenge in each decade of life. Learning new things keeps us humble and alive. In my twenties I focused on teaching and long-distance bicycle travel. In my thirties I moved to Alaska and began doing mountain rescue work. In my forties I wrote a book, changed careers, and learned to drive a boat on the ocean. Each of these new experiences made me feel like I was 20 again, taking me far outside my comfort zone. In future decades I hope to learn a musical instrument well, and travel internationally. I'd also like to take another long bicycle trip and live without a motor for an extended period again. There is great joy in growing old; it's much better than the alternative. :)