On April 13, 2008, Ryan Hall finished 5th in the London Marathon with a time of 2:06:17—the fastest marathon time ever recorded by an American-born runner. Just 14 weeks later Hall ran the Beijing Olympic Marathon, finishing a disappointing 10th. Now, top-10 in the Olympic Marathon is not bad, but Hall knew he could have done better.
After the Games, Hall confessed that his pre-Olympic training had gone poorly. He just couldn’t match the times he was accustomed to posting in key workouts, and the more he fell short the more he tried to force his training, and the more he forced it the worse he felt. In the immediate aftermath of Beijing, Hall wasn’t sure exactly why he had not been his usual self in the summer of 2008, but eventually he figured it out. “Looking back on it,” he said in a recent interview on runnersworld.com, “I think I never let my body totally recover from London so I never made the physical gains that I needed to.”
Many years ago, when asked how long one should wait after running a marathon before running another one, the great Bill Rodgers said, “Until you’ve forgotten it.” Ryan Hall probably defied this wisdom! Seriously, though, it’s not that Hall felt he ran London too close to Beijing. Rather, he determined that he simply did not rest long enough after London. Even though he would have had less time to train specifically for Beijing if he had rested longer after London, his training and the Olympic Marathon itself probably would have gone better, as his body would have been better able to handle the training he planned to do.
I’m not aware of much scientific research on the physiological changes that occur in the body during a rest period that follows a major training ramp-up and peak race. Undoubtedly it involves a deeper level of muscle and joint tissue healing and a more complete resetting of the endocrine and immune systems than occurs during a garden-variety rest week within a training cycle. An Austrian study found that blood levels of antioxidant enzymes remained significantly reduced, while biomarkers of muscle damage and inflammation remained significantly elevated, in triathletes nearly three weeks after they had crossed an Ironman finish line. I would imagine that such abnormalities could be found in runners for at least a couple of weeks after they complete a high-workload training cycle culminating in a peak race.
Whatever happens, it is quite certain that the body requires a prolonged rest between training cycles to perform at least as well in the next peak race as it did in the previous one. It is a phenomenon that every runner experiences. A runner can no more expect to train progressively year-round than a cornfield can expect to produce corn spring, summer, fall and winter.
So, are there any rules concerning how long a runner should rest between training cycles? Not really. But it is possible to formulate such a rule, and I will do just that a bit later in this post. In the place of rules, there are only customs based on the collective experience of generations of runners across the world. Most professional and high-level competitive runners rest two to four weeks after completing a training cycle.
Generally, the greater your training load is within a training cycle, the longer you should rest afterward. Also, the longer your peak race is, the longer you should rest. A runner who peaks at 45 miles per week for a 10K might need only 10 days of rest to “reset” his body and be ready for the next ramp-up. A runner who peaks at 120 miles per week for a marathon is more likely to need at least three weeks of rest.
Rest is relative, and does not refer strictly to complete cessation of running. A transition period between training cycles should begin with at least a day or two of running avoidance. When and how you resume running depends on how much recovery your body needs coming off the last peak and how soon you’d like to peak again. If you really pushed your body hard in the last training cycle, you should not rush your return to running and should start very gently when you do resume running. On the other hand, you don’t want to wait too long, lest you sacrifice too much running fitness and give up all of those hard-earned tissue adaptations to repetitive impact that keep you from getting injured.
TrainingPeaks WKO+ software presents a simple means to strike the right balance between rest and fitness preservation in the transition period between training cycles. In my experience with this program, it is necessary to let go of approximately 20 percent of peak fitness to recover sufficiently to begin another ramp-up. Fitness is represented by the chronic training stress (CTL) variable. Thus, it is necessary to allow your race-day CTL to drop by roughly 20 percent in the post-race period before you begin building it once more in preparation for the next peak.
There’s no need to let you CTL drop more than 20 percent, and doing so will only increase the training burden you must take on to peak again. So 20 percent is pretty much a magic number. Your fitness should drop no less and no more (approximately) between training cycles.
What I like about this magic number is that it allows a lot of flexibility in terms of how long your transition period is and how you train within it. If you want to make a “quick turnaround” between training cycles, you can take more complete rest and resuming running very lightly so that your CTL drops 20 percent quickly. If you wish to take more time between training cycles, you can allow your CTL to drop either quickly or slowly and then train enough to preserve 80 percent of your peak fitness until it’s time to ramp up again.