Eventually, we all slow down; then we stop. For the best marathoners, researchers at Georgia State University have determined, the big slow begins around age 35, and the rate of decline is different for men and women. A Georgia State news release reports that the researchers, who reviewed 2001-2016 data from three of the largest U.S. marathons — Boston, Chicago and New York City, found that top male runners slow down at a rate of about two minutes per year beginning at age 35, and women slow at a rate of two minutes and 30 seconds per year, also beginning at the age of 35. For average runners–those who run in the middle of the pack, there is some good news. They don’t start to slow down until the age of 50, at which point both men and women slow at a rate of 2 minutes, 45 seconds a year. The study also found that runners between 25 to 34 years old had the fastest times, with overall champion males at 28.3 years old and overall champion females at 30.8 years old. The rate of decline from 35 to 74 years old is roughly linear, although female age group winners have a 27-second per year greater decline compared to male age group winners.