I started riding in July of 2008 with no riding since my college years when it was the in thing to do. The first week back riding in July of 2008 I rode 3 rides of about 9 miles and one of 20 miles, the second week I rode 3 rides of 20 miles and one of 40 miles, third week was three rides of 30 and one of 60 miles, the forth week was two rides of 20 miles and one of 101 miles. The 101 miles was an unsupported solo ride that took 7 hours of ride time. I was not in great shape at the time but I did walk about 3 miles a day prior to starting to ride again. Now I know I can ride a century anytime as long as I am getting in at least two 20 mile hill filled fast rides per week. My age in 2008 was 56.