American’s 45-year running streak comes to an end, as Canadian Spafford’s 23-year mark runs on

American runner Mark Covert’s running streak will end today, exactly 45 years after the 62-year-old teacher laced up his shoes on July 23, 1968 to begin at least a mile of running every day. Covert’s streak, at 16,437 consecutive days, is the world’s second longest, according to the Streak Runners International. Former marathon world-record holder Ron Hill, 74, of the U.K., owns the world’s longest streak from December 1964. Covert says he’ll end his streak voluntarily after today’s run, citing a persistent injury in his right foot.

“It’s obviously been a lot of fun and I still enjoy it, otherwise I wouldn’t have done it or kept with it,” Covert tells ESPN.

Canadian run streaker Derrick Spafford says he’ll continue his 23-year streak for the foreseeable future. The Ontario running coach and longtime contributor to Canadian Running hasn’t missed a day of running since Christmas Day, 1989, and doesn’t plan to skip a run anytime soon.

“As a running coach I get asked about [my running streak] a lot,” Spafford says, “and I have to say that I’m usually better at offering advice about this, than taking my own advice. I have run through many illnesses and injuries during this time – some of which I would never suggest trying to run through.”

Spafford can think of many times when he’s been too sick to run and should have taken time off, the two worst examples being a bout of pneumonia with a very high fever, and a potentially deadly skin condition called Stevens-Johnson syndrome. In both cases, Spafford kept his workout to 20 minutes of very easy running, which is the minimum requirement he set to keep his streak alive.

When he was training for track and road races in the 1990s, Spafford recalls running intense interval workouts 2–3 times per week; even if he was fighting upper respiratory infections. “I would get over one illness and then get sick again a short while later,” he says. “Looking back on this now, I realize that this compromised my health at the time and certainly affected my race performances, too.”

For minor illnesses, though, Spafford thinks it’s often safe to run through. “If you just have a common cold with head congestion, an easy run can help substantially to clear your head and allow you to breathe much better,” he says. In those cases, Spafford keep the effort very light, and uses a heart rate monitor to insure he keeps the running easy.