At the 2014 Twin Cities Marathon, 59-year-old Christine Kennedy of Los Gatos, California, ran an age-defying 2:59:39, a time many runners half her age only dream of. All forms of healing take longer, including recovery from hard workouts, something you can't ignore unless you want to spiral into an endless cycle of overtraining and injury. Accumulated wear and tear makes you less flexible. What is known is that age lowers VO 2 max and decreases muscle mass. The reasons for this decline are mixed and not terribly well-understood from a basic physiological level. The rate of decline gradually increases to about 0.7 percent per year (with slight variations among events and between men and women) throughout our 40s, 50s and 60s, according to the current (2010) version of the age-grading tables maintained by World Masters Athletics (available online through numerous age-grading calculators). It's a process that on average begins sometime in our 30s. And even those runners have to accept the fact that try as they might to keep fit and youthful, their bodies inexorably decline. You grow, mature, set PRs and (hopefully) break them again and again.īut there comes a time when the PR chase grows difficult, except for those who entered the sport later in life and are still relatively new to it. You can start as early as grade school and keep going as long as you can put one foot in front of the other. Running, it is often said, is a lifelong sport.