When to Start Running Again after a Marathon?
Marathon runners are certainly a unique bunch of people among an already-eccentric demographic. After spending 4 – 6 months of grueling training for a physically demanding race, a little bit of downtime is necessary, and certainly earned. Many runners struggle with taking a few days off; either out of fear they will lose fitness or simply because they don’t want to break a run streak.
When should you start running again post-marathon? The answer, as well as the variables that affect your body’s response to the long race, are discussed below.
What Happens to your Body during a Marathon?
Before determining how much time is appropriate to take off from running after completing a marathon, it is necessary to understand exactly what happens to the body during the course of 26.2 miles.
After spending 2.5 – 6+ hours on your feet, you will experience more than just muscular damage, chafing, and blisters. At the cellular level1, DNA is damaged due to oxidative stress that takes places in the body. This type of damage, where DNA base pairs do not repair themselves, has been shown to last upwards of one week after a marathon and is believed to contribute to poor immune function after the race.
Immediately following a marathon, inflammation and cardiac damage markers (i.e. c-reactive protein, interleukin-6, interleukin-10, troponin, N-terminal pro-brain natriuretic, and heart-type fatty acid binding protein) reach a peak2, but do not return to pre-race levels for three days, and sometimes longer.
Not surprisingly, muscular damage3 occurs after a marathon. One study looked at calf muscle samples from marathoners before and after a race. Researchers found evidence of muscular damage and inflammation before the marathon even began, most likely due to high-volume training. After the race, abnormalities such as disrupted sarcolemma, red blood cells in the muscle fibers, and contracture knots were prevalent and lasted at least 7-days post-run.
The effects of strenuous activity on the immune system4 are well-studied, and it has been shown by numerous researchers that endurance training can suppress the immune system. Specifically, after a marathon nasal mucociliary transit time is increased, leading the upper airway passages to lack protection. Marathon running is also well-known to increase inflammation, especially pro-inflammatory cytokines, which can compromise the release of anti-inflammatory cells that are necessary for proper immune function.
Based on the damage the body sustains after a marathon, a break from running is necessary in order to help the body repair the damage as quickly as possible. Exercising when inflammation markers are high can further suppress the immune system, disrupt the body’s natural mechanisms for reducing inflammation, and can potentially cause more damage to already worn-out muscles.
One Day for Every K?
A general rule of thumb that is often cited by running coaches is “one day for every k” or “one day for every mile,” meaning that runners may require 42 or 26 days of rest, respectively. While there is no scientific evidence to back up the notion that marathon recovery has a strict number of days assigned to it, there are a few factors that should be considered.
For instance, based on the studies cited above, pre-marathon biomarkers do not return to normal until at least 7 days after the race. In addition, many of these biomarkers (such as inflammation and muscle damage) are already elevated from the effects of heavy training, meaning additional rest is needed in order to reduce the elevated levels to those experienced during pre-marathon training. At a minimum, 7 – 10 days is necessary for overcoming the damage caused by the race, while an additional 3- 4 days is recommended for relieving stress caused by training.
It should be noted that each person will respond differently based on running experience, race-day conditions, and factors such as emotional stress. Even though you may not require 26 – 42 days of full rest, you should be aware that your body is still in recovery mode, even weeks after crossing the finish line. Therefore, once you return to running, it is important to continue your recovery with easy running and cross training as opposed to immediately jumping back into hard training.
Active versus Passive Recovery
There are two types of recovery that runners can engage in when taking down time: active and passive. While it is recommended that runners take at least a little bit of time off completely from running, those who become antsy can engage in active recovery. Light jogging, walking, yoga, or cross training activities (i.e. swimming and cycling) improve blood circulation and provide a healthy dose of endorphins while minimizing additional damage. Active recovery can begin as early as 3 – 5 days after a marathon, but should continue for 2 – 3 weeks after the race.
What the Pros Do
In need of motivation to stay off your feet? It may help to know that most elite marathoners take weeks of full rest after racing a marathon. Professional marathoners such as Desiree Linden, Shalane Flanagan, Kara Goucher, and Meb Keflezighi routinely take 1 – 3 weeks of total rest after completing the 26.2-mile distance, particularly if conditions were poor (such as the high heat during the 2016 Olympic Trials), or if the race was part of a long build up.
Listen to your Body
Even if the number of days you planned to take off have passed, you still may not be ready to resume running. Listen to the cues from your body. If you have any lingering pain, soreness, or swelling, give yourself more time. The majority of runners come down with an upper respiratory infection after a race, so if you are experiencing any symptoms such as headache, sore throat, congestion, fatigue, or cough, allow those symptoms to pass before resuming activity.
Lengthy dehydration is a side effect of racing a marathon, particularly if conditions were hot or humid, so make sure to wait until you feel your hydration levels are under control before heading out the door to run. Additionally, if you are experiencing any common symptoms of overtraining, such as restless sleep, irritability, decreased appetite, fatigue, or lack of motivation, take extra time away from the sport in order to mentally and physically reboot.
Wrapping it up
A break is just as important for mental and emotional health as it is for physical health, and one of the biggest mistakes a runner can make is returning to running without feeling fully ready. On the other hand, if your legs feel fresh, you can’t wait to get out the door, and you feel well-rested, you are likely ready to start hitting the pavement!
1. Tsai K., Hsu T. G., Hsu K. M., Cheng H., Liu T. Y., Hsu C. F., et al. . (2001). Oxidative DNA damage in human peripheral leukocytes induced by massive aerobic exercise. Free Radic. Biol. Med. 31, 1465–1472. 10.1016/S0891-5849(01)00729-8 Link
2. Scherr J, Braun S, Schuster T, Hartmann C, Moehlenkamp S, Wolfarth B, Pressler A, Halle M. 72-h kinetics of high-sensitive troponin T and inflammatory markers after marathon. Med Sci Sports Exercise 43: 1819–1827, 2011. Link
3. Hikida RS, Staron RS, et al. Muscle fiber necrosis associated with human marathon runners. J Neurol Sci. 1983 May;59(2):185-203. Link
4. MacKinnon LT, Special feature for the Olympics: effects of exercise on the immune system: overtraining effects on immunity and performance in athletes, Immunol Cell Biol. 2000 Oct;78(5):502-9. Link