The Science of Running
How to Taper
ou’ve been logging big miles without interruption for, well, almost two years. Now it’s finally time to race (or at least we’re headed in that direction, as I write this). That means more training isn’t better any more. It’s time to cut back – or, in the running lingo, to taper your training. Here’s what the research says about how to balance the benefits of being fully rested with the downsides of losing fitness, plus a few other tapering details to keep in mind.
Back in 2007, researchers at the Université de Montréal combined the results of 27 tapering studies to come up with the perfect recipe for performance. Their recommendation, published in Medicine & Science in Sports & Exercise: a two-week taper during which total running distance was gradually reduced by 40 to 60 per cent, while the frequency and pace of runs remained unchanged.
In practice, the details will vary depending on the individual and the event. For example, a more recent study of British elite runners found that 5k and 10k runners tended to reduce their training by about 30 percent, while marathoners – who presumably racked up more training miles and as a result had more accumulated fatigue – cut their training by 50 percent. In general, the more you train, the longer and steeper your taper will likely be. There’s also plenty of room for individual variation, depending on how long it takes before you get that can’t-help-running-up-the-stairs feeling in your legs.
The key point, though, is not to taper primarily by running less often or more slowly. Maintaining pace and frequency will help preserve your fitness despite the reduced length of your runs. The benefits: more oxygencarrying red blood cells, lower stress-hormone levels and even slightly bigger muscles, all of which add up to a two- to four-per-cent improvement in race times, on average.
Taper your strength routine
There are plenty of good reasons for marathoners to do some strength training, including general health, longevity and, perhaps, injury prevention. It may also make you faster: numerous studies have found that strength training, particularly explosive plyometric exercise, enables you to run more efficiently, burning less energy to cover ground at a given pace. But these workouts need to be dialed back before a big race, too.
suggesting that the balance between increased fitness and accumulated fatigue tilts favourably in the direction of fitness for at least a few weeks after you stop your workouts.
It’s hard to give specific training guidelines based on this study, since we don’t know how performance changed in the first week or two after they stopped strength training. But it’s probably a safe bet that you should dial back the intensity of strength workouts a couple of weeks before the race and do nothing – or just a light maintenance workout or two – in the final week.
Taper your caffeine
This is a controversial one. Caffeine is one of the very few legal performance-enhancers that pretty much everyone agrees actually work. But how much of a boost do you get if you’re already so habituated to your daily dose that you need a couple of ventis just to feel normal? For decades, top marathoners have undergone a ritual purge, forswearing coffee for a week or more so they’ll feel the full benefits when they partake on the morning of the race.
The evidence on whether this ordeal is necessary remains hotly contested. A 2017 study from Brazilian researchers found that cyclists got a 3.3-per-cent boost from a dose of 6 mg of caffeine per kg of bodyweight, an hour before a 30-minute time trial. The key point: the size of the boost was essentially the same for heavy caffeine users as it was for people who rarely consumed any caffeine. That argues against the idea that the benefits of caffeine wear off if you drink coffee every day.
On the other hand, a 2019 Spanish study had subjects take a daily dose of either caffeine or a placebo for 20 straight days, while measuring their cycling performance every few days. Sure enough, the performance boost was biggest in the first few days of the study, and then gradually decreased. The caffeine never stopped working, but the results suggested that a few days of abstinence might produce a bigger boost on race day. Of course, you’ll have to weigh that against the mental anguish that might ensue.
Taper your mind
One last point to keep in mind: one of the unexpected pleasures of the taper is that you’ll suddenly find you have a bunch of free time, now that you’re running half as much as normal. It’s tempting to fill this time with all the chores and errands you’ve been neglecting for the past 12 weeks. Resist this urge, if at all possible.
Over the past decade, a remarkable body of research has emerged demonstrating the powerful effects of mental fatigue on physical performance. As little as 90 minutes of sustained focus on a computer-based cognitive task can have measurable effects on your endurance performance. What is a marathon, after all, other than a prolonged attempt to resist the overpowering urge to slow down? So don’t use the day before the race as an opportunity to finally refile a decade’s worth of taxes. If possible, don’t spend too much of that day in airports hustling to make connections, either. Relax, put your feet up and get ready to suffer.
Alex Hutchinson is a Toronto journalist specializing in the science of running and other endurance sports, and the author of Endure: Mind, Body, and the Curiously Elastic Limits of Human Performance (now in paperback).