I wanna say this without bragging, but just to give you a comparison scale. Me and my babe are 68 and 62, and have averaged 600 miles per month since last June, when we started paying attention. Recently we rode across Florida from Titusville to St Petersburg and back again, almost 500 miles over 12 days, one rest day per 5 days pedaling. The heat was debilitating the first week The overall fatigue was cumulative, and we're just feeling recovered after the ride and the long drive, a week after the end of our ride. Keep riding. It doesn't get easier, but you do go farther and you go a little faster, unless you're hauling luggage, but it's more fun, because you're riding more.