When you grow into your 50s and beyond, know that you still have your best running days ahead of you. Now, before those doubts begin swirling in your brain, just look at the numbers for proof of that 50+ running claim. Recently, Runner's World analysed intriguing run distance data from some of the most popular run tracking platforms – and one of the biggest takeaways? On average, 50+ runners run the most mileage of any age group.