Gotta say that I'm more worse for the wear at 50 than I was 10 years ago even.
At 40, I had been a competitive mountain biker for about 15 years. Had shattered my elbow when I was 39 and was off the bike for a long time, but still competitive when I started riding again and medalled in a few races the year I turned 40. I used to do a LOT of XC skiing int the winter after messing up my knees doing freestyle DH skiing in my youth.
But between 40 and 50, I've:
- broken 5 ribs in a bike accident, permanent loss of sensation on my thighs from a L2-L3 spinal compression
- severed nerve and tendon in left index finger - surgery saved the finger, but lost range of motion and utility; had to curtail my weight training for a very long time as I couldn't pick anything up in my left hand for months.
- lower back injury; kept me off the bike and out of the gym for a hear; ongoing sciatica if I'm not careful.
- Achilles tendon injury; sports related and ended my winter activity of curling 2-3x per week. That was two years ago and I'm just now able to walk with almost no pain.
I guess my thinking was that I could do all the stuff I could do with the same intensity that I could when I was in my 20s and 30s. But all this has conspired to reduce my athleticism and intense activity levels to almost zero. Food and booze intake has increased as well. The sedentary lifestyle has added a good 60-70lbs on my frame. Fighting weight for me was 195-200lbs. Haven't seen that for a long time. Even going on a spirited recreational bike ride with my buddies is out of the question, I'm so far gone. I think my lack of fitness is why I'm dealing with pneumonia right now instead of just a 2-3 day flu.
That said, I do a lot of off-road motorcycling and regularly work around my cottage (building stuff, clearing bush, chopping wood, swimming, kayaking, snowshoeing, etc) so I'm not a complete lump. It's gotten to the point that I'm considering dusting off the golf clubs and having that be my main "sports" activity!
So, all I can say is - keep active and try not to hurt yourself in your 40s! You're not in your 20s anymore you know....