Please tell us your age. 50
1. What type of bikes do 50+ folks ride?
I have a Trek 7200 hybrid and a Lashout electric bike.
2. Do you take any special supplements/vitamins/minerals as you have grown older?
Just a multi-vitamin and extra calcium.
3. How much do you feel you have "slowed down" if any?
Actually, I feel better now than in previous years. My "slow down" was five years ago when I had some knee problems which were improved by strengthening leg muscles.
4. How long have you been biking? New, around a while, biked all your life?
I rode as a kid but only a few blocks at a time to play with friends. My husband bought me a Raleigh Talon mountain bike in the late 80s which I rode occasionally but for some reason, it didn't "take." Then in March of this year, my sister mentioned that she was starting to ride for exercise and the lightbulb went off in my head. I had never really found a sport or exercise that I enjoyed enough to keep at it. So I took the Raleigh in to get fixed up, stuffed it in the back of my convertible, and went riding at the veloway. I enjoyed it so much that I drove straight to the LBS and bought a rack. After a couple of months of that, my husband decided to get a bike. I was going to have slicks put on mine and see about getting a better fit when they told me my bike was too small for me. No wonder it was so uncomfortable! So I got the Trek. My husband and I both turned 50 this summer and these were our birthday presents. 
Funny thing is, my sister hasn't ridden in months!
5. What type of biking do you do? Long rides, touring, short rec rides, commute, tour, race?
I started with after-work rides at the veloway and then started a partial commute of 12 miles rt this summer. Beginning next week, I'll be doing a one-way 17-mile commute and eventually hope to do the full round trip. My husband and I occasionally ride together on the weekend.
6. How often do you bike? Your approximate annual mileage?
Four to five times per week, maybe 2000 miles?
7. Do you do any other type of physical activities - weight lifting, skiing, running, etc.?
I haven't done anything else once I started cycling. I need to get back to using the elliptical and home gym on days I don't ride. We enjoy skiing but usually only get to go once a year, if that.