The typical professional runner runs twice a day almost every day. The typical recreational runner runs twice a day never! Why not? Obviously, some just don’t have the time, or at least don’t think they do, whereas others simply have no interest in “doubling,” as it’s known. Many just assume that only professional runners can handle or benefit from running twice a day.
Although it’s certainly not for everyone, doubling can be a safe and efficient way to increase fitness and performance, even for middle- and back-of-the-pack runners.
The Benefits of Doubling
It’s easy to assume that professional runners can handle doubles simply due to their innate running talent, but this is false. Exercise scientists use the term trainability to refer to an athlete’s capacity to gain aerobic fitness in response to training. The genes that confer trainability are completely distinct from those that underlie built-in fitness, and they’re a lot more common.
In one study, scientists created a system for scoring trainability based on how many of the relevant genes an individual had, then scored a population of 456 nonathletes. While there was a high degree of inter-individual variation, a significantly greater number of subjects (52) had the highest possible score than the lowest (36). In other words, more of us are highly trainable than not.
The average self-described amateur runner logs about 40-50km per week. Because, in most cases, this number does not represent the maximally effective volume of training for that individual, it’s safe to say that most runners could get fitter if they ran more. The specific benefits of higher mileage include increased aerobic capacity, improved running economy, and leaner body composition.
There are two ways to increase running volume: run longer and run more often. Of these, running more often is slightly gentler on the body. For example, a 10km run in the morning followed by a 10km run in the evening will generate less tissue damage and inflammation than a single 20km run. This is why most professional runners double routinely instead of completing one longer training session each day.
Making Doubling Doable
If you think that doubling is crazy for a runner like you, it’s probably because you assume it has to be done in a certain way—namely, the professional way. But it doesn’t. Let’s deconstruct the various perceived requirements of doubling and then reassess whether the practice truly is crazy for a runner like you.
You don’t have to double every day!
True, most pros run twice a day almost every day, but that doesn’t mean you have to. In fact, you shouldn’t make any sudden leaps in training frequency. If you’re currently running 4 times per week, then try 5 (via 1 double day). Doubling just once per week will result in a meaningful increase in training volume that will in turn elevate your fitness and performance.
If 5 runs per week feels like your limit, then stop there. Otherwise, try adding a second double elsewhere in the week, and so on, until you’re running as often as you care to or can comfortably handle. The ideal time to double is on the afternoon or evening of a hard morning workout. Doubling on easy days is less optimal because it reduces the contrast between hard and easy days. But there’s no harm in slotting in your easy runs wherever they fit best in your schedule and seeing how your body responds. As long as you don’t find yourself falling behind on recovery and performing poorly in key workouts, you’re good to go.
You don’t have to do double runs all year
You can use doubling for those times when you are trying to get as fit as possible for an important race. Just be sure to ease back into the practice each time and not pick up where you left off many months before.
Your second run of the day doesn’t have to be long (or fast).
Even the pros seldom go farther than 10km in their second run of the day, and those miles are almost always very easy. And while it is the norm to do the bigger run in the morning and the lighter one in the afternoon, reversing this order works fine for runners who need to save their bigger run for the afternoon for practical reasons.
Your second workout doesn’t have to be a run.
There’s no rule that says your second workout of the day has to be a run. If you’re concerned about injuries, add low or zero impact cardio sessions on a bike or elliptical trainer instead. Much of the fitness you gain from these activities will transfer over to your running.
Article Credit – Matt Fitzgerald, www.trainingpeaks.com/blog/doubling-for-mortals