The First Rule of Running After Childbirth Is That There Is No Rule

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At first, I was a little disappointed with a new review of guidelines for resuming training after giving birth, published last month in the British Journal of Sports Medicine. The authors had screened 5,851 relevant studies, reviewed the full text of 602 of them, and extracted guidelines from 33 of them. Pooling all this information had produced the following definitive conclusion: “Few guidelines in the scientific literature on RTA (return to activity) and RTS (return to sport) postpartum exist, and most are vague and inconsistent.”

I’d been hoping for some simple numbers: a timeframe, or at least a roadmap with some key benchmarks. That’s the kind of guidance that could be really useful for women who have recently given birth or are planning to, I figured. But upon further reflection—and after exchanging emails with the review’s lead author, Jenna Schulz of Western University in Canada—I’ve reconsidered. Returning to sport after becoming a mother can be a complex and highly individual process, with potential traps that can snare even the most knowledgeable and well-supported athletes. We don’t need simple numbers; we need a better understanding of that complexity.

For starters, it’s worth acknowledging that there are a few numbers in Schulz’s review. A common theme in the various postpartum exercise guidelines she surveyed is that women can aim to do about 150 minutes of moderate to vigorous exercise (i.e. hit the standard exercise guidelines for adults) around six weeks after giving birth. But this timeframe doesn’t come from high-quality randomized trials. “I think some of it is opinion, but a lot of it is likely based on general tissue healing time,” Schulz says. If you break a bone or roll an ankle, the doctor will put you on the shelf for six to eight weeks; the guidelines seem to assume that recovering from childbirth will follow a similar trajectory.

But the experience of childbirth can vary dramatically between people, so even if that number turns out to be correct on average, it’s not necessarily a useful guide for individuals. In a 2018 Outside article, Megan Michelson recounted some of the varying experiences of elite athletes. Marathoner Paula Radcliffe started running 12 days after giving birth, and won the New York Marathon nine months later. Climber Beth Rodden, on the other hand, couldn’t tackle challenging routes for more than a year. “I was under the assumption that since I was an elite professional athlete, I would get back to normal quickly after birth,” Rodden said. “For me, the first few weeks after birth, I couldn’t walk around without extreme pain and pressure and feeling like my insides were going to fall out.”

Similarly, a study published last year (which I wrote about here) surveyed 42 elite distance runners about their experiences during and after pregnancy. On average, the women started cross training three weeks after giving birth, resumed running after six weeks, and had returned to 80 percent of pre-pregnancy training levels after 14 weeks. But if you look beyond the averages, there was enormous individual variability: the 80-percent threshold was 14 weeks with a standard deviation of 11 weeks.

That’s why Schulz cautioned me not to get too hung up on numbers: “My personal belief is instead on focusing on timelines, it should be focused on ability, i.e. do they have adequate strength, are they ready mentally, do they have the right social support, are they exhibiting any symptoms, are they eating enough, sleeping enough, etc.”

Meeting those thresholds isn’t always straightforward. Molly Huddle had a relatively successful run in New York earlier this month, in her first marathon since the birth of her daughter a year and a half earlier, placing ninth in 2:32:02. But her path to the race wasn’t smooth. In March, she suffered a femoral stress fracture—an injury that kept her from running until July, and that she suspects might have been linked to the added demands of breastfeeding.

In a direct sense, breastfeeding takes extra calories that could tip you toward relative energy deficiency in sport (REDs), which is associated with compromised bone health. But there’s also a more subtle link. Another new article in the British Journal of Sports Medicine highlights the “biopsychosocial overlap” of lactation and REDs: it can be hard to tell them apart. Both conditions can be associated with weight change, sleep disturbances, decreased libido, altered menstrual cycle, and other changes. As an elite endurance athlete, Huddle is hyper-attuned to the risks of REDs, but in a recent interview she speculated that she might have missed the warning signs because she was still breastfeeding.

It’s also worth emphasizing that it’s not just about physiology and physical healing. Two other new studies in the British Journal of Sports Medicine address some of the broader challenges of postpartum training: confronting stereotypes, working with coaching and trainers who don’t have experience with new mothers, dealing with postpartum depression, and—perhaps most crucially—finding time, energy, and childcare. It doesn’t really matter whether your ligaments are ready if you don’t have someone to take care of the baby while you train.

In other words, yes, we need more research on female athletes in general, and on new mothers in particular. But there are plenty of things we can do right now to help smooth the return to training after childbirth. For new mothers, that means recognizing that every return from pregnancy is different and there’s no default timeline. For the rest of us, a good start would be to see all the postpartum athletes around us, recognize the challenges they’re encountering, and celebrate their achievements.

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