The study aimed to develop insight into musculoskeletal pain experienced by women when running during pregnancy. Informed by a diverse cohort of women who ran during any part of their pregnancy, the study findings offer novel insights that may be of interest to those who wish to run themselves or practitioners aiming to facilitate and support running during pregnancy.

Many women aim to continue running during pregnancy; however, participation has been reported to decrease as pregnancy progresses, with only 31% of competitive runners continuing to run during their third trimester [6]. The women surveyed in the current study reduced their mean running distance compared to pre-pregnancy by 23%, 36% and 45% from the first to third trimester, respectively. This progressive reduction in training volume throughout pregnancy is consistent with that documented elsewhere in pregnant elite runners (45%, 50% and 70%), when considering their mean pre-pregnancy running volumes (elite: 114 km/week vs diverse survey cohort: 23.5 km/week) [27]. Progressive decreases in frequency, intensity and time of cardiovascular and resistance training exercise of 49%, 72% and 80% across trimesters have been previously documented [28]. Guidelines for physical activity during pregnancy encourage the accumulation of physical activity over a minimum of 3 days [4], which was the average number of runs our participants completed pre-pregnancy, and across the two first trimesters of pregnancy in those who continued to run. As reported in this survey, women do continue to run throughout their pregnancy, and in many cases (n = 223, 7.2%), women run up to the week they give birth. Healthcare professionals may support pregnant women who wish to run during their pregnancy by managing their expectations of running volume, and noting that a reduction in running distance and frequency is common as pregnancy progresses.

Despite running shorter distances and less often compared to pre-pregnancy, 86% of the studied cohort reported experiencing pain while running during pregnancy. Pain was most prevalent at the pelvis/SIJ, lower back, abdomen, breast and hip (prevalence at each listed site ≥ 39.5%), with the most prevalent severe pain experienced at the pelvis/SIJ. It is of note that the sites of greatest pain prevalence are within body regions that undergo the greatest anatomical changes during pregnancy. As pain is one of the main perceived barriers to training during pregnancy [28], regions of substantial structural change require greater attention to support women’s ability to continue running through pregnancy. Further investigation of the usefulness of interventions such as working with a physiotherapist or other health professional, the type of breast support and the use of belly banding for pain reduction during running is warranted.

Importantly, pain during pregnancy has been identified as a risk factor for pain in postpartum runners [29], demonstrating potential long-term consequences of high during-pregnancy prevalence rates. Musculoskeletal pain prevalence rates during pregnancy from the current study (86%) aligned with postpartum runners studied previously (84%) [30]. In contrast to our current study findings, which exposed proximal body sites to be of most concern for pain, distal sites, specifically the lower limbs, have been found to be the regions of greatest musculoskeletal pain in a postpartum cohort [30]. Further research investigating the relationship between during-pregnancy pain and postpartum pain is needed to progress current understanding to support women’s engagement with running during this time of substantial physical change.

Approximately 40% of surveyed women experienced breast pain when running during pregnancy. A novel finding of the current study was that women who had a previous child were at significantly lower odds of experiencing breast pain while running during their subsequent pregnancies. During pregnancy, the breasts undergo structural changes [31], becoming larger and often warranting a revision of breast support [32]. During pregnancy, a complete remodelling of breast tissues occurs that does not return to the pre-pregnancy state post-lactation [31], likely accounting for the reduced odds of experiencing breast pain in subsequent pregnancies. Ensuring adequate breast support during running, particularly for women in their first pregnancies, may help reduce instances of pain, as has been found for women with larger breasts [32]. Providing targeted recommendations to pregnant runners regarding breast support is challenging given the absence of research on breast biomechanics of pregnant women [33]. Further research into breast biomechanics while running during pregnancy is required to inform practices. The experience of breast pain may not only limit running during pregnancy, but it is also a perceived barrier to returning to running postpartum [28].

Although having a previous child reduced the risk of experiencing breast pain, the odds of experiencing pain at the pelvis/SIJ, hip, knee and lower back were greater (OR ≥ 1.26) for those who had previous children. Previous findings have demonstrated altered gait mechanics postpartum compared with nulliparous controls [34]. Our observations of increased odds of running pain while pregnant with successive pregnancies may therefore, in part, be a consequence of altered running gait mechanics. Associations have additionally been evidenced between altered gait mechanics and pain in nulliparous populations [35, 36]. Although it is challenging to conduct longitudinal studies in pregnant women, analysis of running gait mechanics and pain experienced across successive pregnancies would provide valuable insight to inform approaches for pain prevention.

Those with any recurring pre-pregnancy injuries had over two times more risk of experiencing lower-limb pain during pregnancy, specifically at the knee, ankle and calf. Our findings align with research from nulliparous populations, which reports previous injury as a main running-related injury risk factor [19, 37], with running injuries predominantly located in the lower limbs [13]. Although to a lesser extent, previous recurring injuries also played a role in increasing the odds of experiencing pain at the hip, pelvis/SIJ, foot, breast, abdominal region and lower back during pregnancy in the women surveyed. Details of pre-pregnancy injury, and the extent to which the runners had recovered from those injuries prior to running during pregnancy, were not measured within the current study. These factors are important to further investigate to progress current understanding of factors associated with pre-pregnancy running-related injury [38].

Women who stopped running earlier in their pregnancy presented with greater odds of pelvic/SIJ and breast pain, suggesting pain experienced at these sites was the greatest musculoskeletal barrier to continuing to run during pregnancy. Efforts to introduce pain prevention, reduction and management strategies (e.g. gait training to reduce joint loads [37] and improved breast support [32]) should place emphasis on the pelvis and breasts. Those with more pre-pregnancy running experience were additionally at greater risk of pelvic/SIJ pain, whereas those with less running experience before becoming pregnant were more likely to experience knee pain while running during their pregnancy. As within a nulliparous population, less experienced runners tend to have a greater rate of lower-limb injuries [39]. For novice runners, a progressive running approach is recommended to allow anatomical adjustments to running stresses [38]. Sharing this information with women who are trying to become pregnant, or who are early in their pregnancy, may support them to be able to continue to run during pregnancy, should they wish to.

A prominent strength of this study was the international cohort of women who shared their pre- and during-pregnancy running experiences. Our study cohort had a broad range of ages (34 ± 3.9 years; 22–52 years) and running experience (8.6 ± 6.0 years; 0.5–35 years), albeit with a high proportion of experienced runners (72.5%). Data were collected from December 2021 to March 2022; subsequently, many of the participants will have reported on pregnancies during the coronavirus disease 2019 (COVID-19) period. It is likely that restrictions on events, outdoor activity, gym access, etc. will have disrupted the typical running behaviour of many participants. Like all studies involving the recruitment of volunteers, the study was subject to non-response bias, which could have impacted the degree to which the samples accurately represent the wider population of women who ran during pregnancy.

The current study was retrospective, and the ability to recall pain along with other running habits and personal details (e.g. pre-pregnancy injury) was likely impacted by the passage of time. While the recall period was purposely limited to 5 years, with a cohort mean of 1.9 years, it is likely that the accuracy of responses was impacted by the retrospective nature of the study and the length of the recall period. To limit recall bias, future prospective studies are recommended that follow guidelines [40] on methodology for recording overuse symptoms, including pain, in sports.

An additional limitation of the current study was the lack of data collected on pre-pregnancy pain and during-pregnancy injury. The decision to focus on during-pregnancy pain was purposeful, as outlined previously; however, additional data on whether pain translated to an injury during pregnancy would have been of additional interest. Similarly, the decision to include pre-pregnancy injury as a personal risk factor was made in line with previous research; however, knowledge of pre-pregnancy pain during running would have also been of interest to expand the current analysis. The relationship between pain and injury in running requires more attention in future research.

The current survey did not encompass all musculoskeletal issues experienced by women who run during pregnancy. It is well understood that pelvic health issues often play a significant role in women’s physical experiences during pregnancy. Incontinence and pelvic floor issues were not considered within the current article; however, research in the respective areas is important to contribute to the knowledge supporting women who wish to run during pregnancy.