How Long Is Long Enough?

Ask the Coach

I’ve heard conflicting information about long training runs for a 100-miler. Some feel that seven-plus hours or …

Illustration by Jeremy Collins

I’ve heard conflicting information about long training runs for a 100-miler. Some feel that seven-plus hours or 40- to 50-mile training runs are essential. Others say you don’t need more than four hours or 30 miles. For me, the benefits of longer runs seem to be attained at 30 miles and anything more just breaks down my body and leads to injury. What is your advice?

—Tim Long, Boulder, CO

If you read any marathon training book, you’ll see most programs don’t even have you break the 20-mile barrier in preparation for the 26.2-mile distance. Many recommend 18 miles as the longest long run. The logic behind a plan like this is that you receive diminishing returns as you get too close to race distance.

In training for a 100-miler, you could run 50 miles as a long run, but how long would it take to properly recover? Is the increased risk of injury worth the extra miles or time on your feet? How long is long enough is personal to the individual athlete. Someone who has just started running ultras with the goal of just finishing cannot, of course, handle the same long run distance as an experienced veteran.

But Karl Meltzer, who has thousands of miles under his belt and won more 100 milers than anyone, ever, is also a coach and a fan of quality over quantity. He says, “I don’t schedule runs longer than 20 miles when training for any 100-miler. I feel it’s too hard to recover in one evening to have an effective run the following day.” In short he favors building a mileage base with consistency over doing super-long runs to get “closer” to the 100-mile distance.

Ultimately if you have gradually extended your long run without injury, cranking out 30 or 40 miles could be the challenge you need, but not if it takes two weeks to recover.