Why Marathoners Need to Build Their Sprint Speed
A leading exercise physiologist suggests developing a top speed two times faster than your marathon pace for a “speed reserve.” Here’s how to improve yours.
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Marathoners generally don’t lose any sleep over how fast they can sprint, nor do they spend time developing their top-end speed. But Veronique Billat, a French exercise physiologist and author of The Science of the Marathon, argues that marathoners also need to have a sprint gear, even if they don’t use it in their races.
Part of what helps give marathoners the endurance they need, she says, can be described by a concept exercise physiologists call a “speed reserve.” During the race, marathoners are never running close to their all-out velocity. The more speed they have in reserve, the better and more efficiently they can run at the slower pace of the marathon. In fact, Billat says, the ideal marathoner should have about a 50 percent reserve—meaning a maximum sprint speed of about twice their marathon pace.
She isn’t talking about 100-meter–dash speed. If you do the math, you’ll find that marathon world record holder Eliud Kipchoge averaged 17.4 seconds each 100 meters while covering 26.2 miles in 2:01:39. Cut that in half, and you get 8.7 seconds. If Kipchoge could actually do that, we’d call him Eliud Bolt and give him records in both the marathon and the 100 meters. But by Billat’s standards, the 100 is a paced run, with even the world’s best performers hitting maximum speed fairly early on and then hanging on for dear life as fatigue gradually makes them slow. What she’s talking about is peak, instantaneous speed—the fastest pace you can reach after a brief, all-out acceleration.
To measure this, says Jonathan Edwards, a Florida-based researcher who has watched the process, Billat equipped runners with high-tech GPS monitors and accelerometers capable of capturing their movements as often as 50,000 times per second. Using that, he says, Billat could detect their top speed at the brief moment before it begins to decay. Her two-to-one ratio comes from testing and comparing this top speed with the race pace of sub-2:30 male marathoners.
Sadly, you can’t measure your top speed without the type of expensive laboratory equipment Billat uses. Furthermore, even if you could capture your absolute top speed, Billat’s ratio is meant to be more of a guideline than a rule, so you can’t predict your marathon time using it. The clear takeaway, however, is that in order to run your best marathon, it’s useful to be able to run really fast—if only very briefly—and it’s worth your while to spend some training time building that speed.
Recruit All Your Muscles
Physiologically, training your sprint speed helps build two processes that are important at longer distances. One is what exercise physiologists term neuromuscular recruitment, in which the brain learns to employ more muscle fibers and cycle them in and out of use as efficiently as possible.
The effect is something like building a ladder—you need a strong step at each level in order to climb to the next one. Bob Williams, a coach who trained under Bill Bowerman, says that to run a solid marathon, you have to be 10K or 5K fit. “You have to have the reserve to be able to make the rhythm of running your marathon pace feel really good,” he says. But to have that at the 5K or 10K distance, you need the reserve to be able to do a decent 3K. Williams points out that Kenny Moore, who placed fourth in the 1972 Olympic Marathon, could run close to four minutes for the mile.
If you think that’s ancient history, from a period before runners started specializing, think again. Sara Hall, who recently clocked a marathon finish of 2:20:32 and who earlier this month broke the American half-marathon record with a time of 67:15, once had a 1,500-meter time of 4:08.55 in her arsenal. Speed at the short distances builds efficiency that carries up the ladder to the longer ones.
Be a Better Lactate Shuttler
The type of training it takes to build a speed reserve also helps develop your lactate shuttle. Lactate shuttle is the process by which your body moves lactate from hard-working muscle cells in the lower body into your bloodstream, where it can be taken up by cells in the heart, brain, liver, and arms, sparing precious glycogen for use in the all-important legs.
There are many ways to boost this process, but Christine Brooks, a sports scientist at the University of Florida who develops coaching curricula for USA Track and Field (USATF), says it’s dependent on two transporter molecules in the cell membranes, called MCT1 and MCT4.
MCT1 allows cells to import lactate from the bloodstream in order to make their best use of it. It’s built by endurance running, Brooks says. MCT4 does the reverse: it strengthens the lactate shuttle by helping the hardest-working cells to export lactate into the blood and, in the process, reduces their fatigue. MCT4 is built by running fast enough that the muscle cells in your legs really want to get rid of the lactate accumulation.
Touch Top Speed
To train marathoners’ speed reserve, coaches tend not to worry about the exact pace but instead focus on getting runners to regularly hit their top gears.
“We believe in ‘touching speed’ throughout our training cycles,” says Mike Caldwell, coach of the ASICS Greenville Track Club-Elite. “Our marathon training is not too different than our regular distance training for 8K and upward, so incorporating some faster work is typical.”
Caldwell likes 100-meter strides—run fast but not all-out—a few times per week. Or he’ll tack on five to eight 200-meter cutdowns (each run progressively faster) after moderate-effort tempo runs.
As a coach of adults from beginners to Olympic Trials qualifiers, I use something similar. About once a week I’ll add two to six 200-meter repeats, run at a mile pace or a bit faster, to the end of a longer-interval workout. Or I’ll have runners do two to four 150-meter sprints, run at roughly an 800-meter pace, after a tempo-style workout.
Williams likes 30-meter flies, a sprinter drill that can benefit distance runners as well, in which you steadily accelerate for about 30 meters, hit maximum pace for 30 meters, and then decelerate gradually. He suggests three to four of them, resting for at least three minutes between each. “You have to have lots of recovery,” he says. And that’s not something you tack on at the end of another workout. You can do some easy miles, he says, “but that’s all the intensity you do that day.”
Scott Christensen, a USATF endurance instructor and distance coach, is also a fan of the flying-thirties workout. “It is good training for the speed, strength, flexibility, and coordination that define athleticism,” he says. You only need to do it once every two weeks, he adds, on a day when everything else is easy.
There is no magic formula for top-speed training. Find what works for you to feel fast without undue stress. Then time the result, or get a friend to do it for you, and track changes in your sprint speed—whether at 200’s, 150’s, 100’s, or 30–meter flies. Christensen recommends tracking your progression in both top-speed and marathon pace, noting how they correlate, and working to improve your speed reserve.
There are, however, a couple of caveats.
One is that this type of speedwork is still speedwork. When constructing a workout that includes top speed, you need to reduce the volume of the other parts in order not to overtax yourself. You can’t stick 200-meter repeats on at the end of a set of 1,200’s without dropping at least one of the 1,200’s to make room for them. Even four sets of 150 meters is taxing enough that it’s wise to reduce the rest of the workout’s volume by 1,000 meters or so.
Another is that, of course, the marathon remains an endurance event. Sprint work is useful to improve your speed reserve, but it’s no substitute for the endurance work that forms the heart of marathon training, and it should only be a fairly small fraction of your overall work.
And finally, masters runners shouldn’t expect to have the same amount of speed reserve as they did when they were younger. That’s because, as you age, your sprint speed fades faster than your endurance, shrinking your reserve, Brooks says. But that doesn’t mean masters runners should throw in the towel on speed. Rather, she says, they can and should continue to touch their top speed regularly, whatever pace that may be. “I’m 73,” Brooks says. “I know I can’t do what I used to do. Do the best you can.”