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If you’ve missed days of cycling because of having COVID-19, you might be tempted to make up for lost time by rushing back into training. Not so fast, according to research that suggests doing so could significantly increase your injury risk.
For a study published in Sports Health, researchers surveyed runners who have completed a race or triathlon between July and September 2020. The participants were asked two key questions: whether they had had COVID (as determined by a positive test or a medical professional’s diagnosis) and whether, since March 2020, they had been injured badly enough to miss at least a week of exercise. All respondents were at least 18 years old and had raced at least once in 2019; 56.5 percent of them were women.
Of the nearly 2,000 respondents, 6.3 percent said they’d had COVID. Between March and September 2020, 30.9 percent of participants were injured, compared to 21.3 percent of the COVID-free participants. The takeaway: The athletes who had had COVID were 1.66 times more likely to get injured than the others.
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Why injury may spike
The study authors are quick to note that their data on both COVID infection and injury were self-reported by respondents. Also, the researchers didn’t measure the timing of infection and injury—such as whether injuries tended to occur a certain number of weeks after infection—so direct causation can’t be known.
Still, the study authors were struck by their findings. “I was not surprised there was a difference in injury rates [between infected and uninfected athletes], but I didn’t expect it to be as big of a difference as we found,” lead researcher Brett Toresdahl, M.D., of the Hospital for Special Surgery in New York City, told Runner’s World.
Why might athletes who have had COVID get injured more easily? After all, many cyclists regularly take time off, such as immediately after a big race, when they have some other illness, or simply when their non-cycling lives get too busy.
If otherwise healthy, a couple of weeks off doesn’t result in much deconditioning for most athletes, Toresdahl said. “However, illnesses can cause more significant decreases in strength and fitness. COVID-19 can cause more systemic effects than a typical cold, which may explain our findings in this study.”
In the study, 41.4 percent of those who had COVID reported moderate to severe symptoms. “These runners likely took several days—or weeks—off from running because of their symptoms,” Andrea Myers, a doctor of physical therapy who works with runners and other endurance athletes in Southbury, Connecticut, said. “Depending how long they took off from exercise, they may have lost strength, VO2 max, and/or lean body mass.”
As Myers points out, between illness and quarantine, the athletes with severe COVID could be considered akin to hospital patients confined to bed rest. Research has repeatedly documented the quick and significant loss in cardiovascular and muscular fitness from bed rest. In one study, VO2 max, a common measure of aerobic fitness, declined by 17 percent after just 10 days of bed rest. Moreover, some studies have suggested that bed rest causes a sharper VO2 max drop in fitter people than in less-fit people.
Caution after COVID
All that being the case, Toresdahl and Myers say that it makes sense that cyclists resuming training after having COVID could be more susceptible to injury. Because cyclists would be significantly less fit than possibly even a few weeks earlier, and they might use the difficulty they have in returning to cycling as motivation to push that much harder, thereby further increasing their injury risk.
In the study, there weren’t significant differences in types of injuries between the COVID and non-COVID athletes, suggesting that declines in overall aerobic, muscular, and skeletal strength were a key factor.
Toresdahl and Myers also agree that cyclists who have had COVID should return to cycling more conservatively than after other reasons for an extended break. An infographic published in the British Journal of Sports Medicine recommends not resuming any form of training until you’ve been symptom-free for seven days, even if your symptoms were mild or moderate. According to the infographic, start with no more than 15 minutes of light activity, like a low-intensity ride on your stationary bike, and take at least a week to gradually increase duration and intensity. Even if you remain symptom- and injury-free, wait at least two and a half weeks from when your symptoms started to resume full training, the infographic advises.
“It’s normal to have bumps along the road to recovery—if you have a day where you feel fatigued or sore, back off the following day, and then get back on track. Recovery is rarely linear, and setbacks are common. Injuries occur when we put too much pressure on ourselves and ignore what our bodies are telling us,” Myers says.
If your case of COVID required hospitalization or caused heart symptoms such as chest pain or racing heartbeat, Toresdahl advises consulting with your primary care or sports medicine physician before resuming cycling.
Scott is a veteran running, fitness, and health journalist who has held senior editorial positions at Runner’s World and Running Times. Much of his writing translates sport science research and elite best practices into practical guidance for everyday athletes. He is the author or coauthor of several running books, including Running Is My Therapy, Advanced Marathoning, and Meb for Mortals. Scott has also written about running for Slate, The Atlantic, the Washington Post, and other members of the sedentary media. His lifetime running odometer is past 110,000 miles, but he’s as much in love as ever.
