Abdominal Exercise and Diastasis Recti During Pregnancy
WHEN encourages caution around loaded abdominal exercises such as loaded flexion exercises during pregnancy. Recent research found these exercises did not significantly increase muscle separation. This is useful but it is not the whole picture.
The studies measured one thing. They did not measure pelvic floor load, intra-abdominal pressure, or how women felt in their bodies. The pregnant body is a whole system. One measurement cannot tell us whether an exercise is safe for that whole system.
WHEN supports women moving throughout pregnancy. This position is not about limiting exercise. It is about ensuring decisions are based on the full picture, not a partial reading of the evidence.
Full Position Statement
Background
Two recent randomised controlled trials published in the Journal of Physiotherapy examined whether abdominal exercises during pregnancy increase the separation of the abdominal muscles, known as diastasis recti abdominis (DRA). These are Cabral et al. (2025), a three-arm trial examining transversus abdominis and rectus abdominis activation exercises in healthy primigravida women, and Theodorsen et al. (2024), an exploratory trial examining combined abdominal and pelvic floor muscle training in women with confirmed DRA. Both studies found that the exercises examined did not significantly change the inter-recti distance (IRD) when measured by ultrasound. These findings are being widely discussed across allied health and fitness communities. Some are interpreting the results as evidence that loaded rectus work, including loaded flexion exercises, is safe during pregnancy.
WHEN does not support this interpretation.
WHEN Position on Abdominal Exercise in Pregnancy
WHEN welcomes these studies and the contribution they make to the evidence base. Understanding what does and does not affect inter-recti distance during pregnancy is genuinely useful, and this research moves that conversation forward. It is important to note that the authors themselves do not claim their findings mean all abdominal exercise is safe during pregnancy. These studies were designed to answer a specific question about IRD. They were not designed to assess the safety of loaded rectus work as a broad category of exercise, and they should not be interpreted that way.
IRD is one piece of a much larger picture. Our approach has always been to look at the whole woman, not just a single measurement. The pregnant body is a complex, interconnected system and we believe exercise guidance during pregnancy needs to reflect that complexity rather than rest on one outcome alone.
Our position rests on eight considerations:
- Inter-recti distance is one measure of one structural change
Both studies measured IRD, the width of the linea alba. Pregnancy exercise influences far more than this single dimension, including intra-abdominal pressure, pelvic floor loading, trunk stability, fascial integrity and movement comfort. A narrow measure cannot answer a broad question about safety.
- IRD width isnot the same as abdominal wall function
Two women can have identical IRD measurements but very different abdominal wall function. Tension in the linea alba, fascial quality and neuromuscular control all determine how well the abdominal wall is working. Width alone does not capture this, and function is what matters clinically.
- Pelvic floor function was not adequately assessed
Cabral et al. (2025) included a self-reported symptom questionnaire. Theodorsen et al. (2024) did not measure pelvic floor outcomes at all. Neither study measured objective pelvic floor function, including muscle strength, structural support, or pressure transmission during movement.
Self-reported pelvic floor symptoms are notoriously unreliable. Women consistently underreport dysfunction because there is no shared understanding of what incontinence actually means. A woman who leaks urine when she sneezes is experiencing urinary incontinence, but most women do not classify it that way. The stigma around pelvic floor dysfunction means women normalise symptoms rather than report them. This makes self-report a poor tool for measuring pelvic floor impact and means the questionnaire data in these studies likely underestimates the true picture.
The pelvic floor is not a passive structure. Under loaded rectus work, it absorbs increased intra-abdominal pressure. That load was not measured objectively in either study. Beyond urinary incontinence, loaded rectus work and increased intra-abdominal pressure during pregnancy may also have implications for pelvic organ support. This was not measured in either study and warrants further investigation.
- The exercises were tightly supervised and controlled
Both studies used supervised, moderate-intensity exercise in controlled clinical environments. In Cabral et al. (2025), sessions were conducted in groups of five at a university clinical facility by a physiotherapist with nine years of experience in women’s health, with intensity carefully controlled throughout. In Theodorsen et al. (2024), the loaded flexion was performed as sit-ups in slings under the supervision of a physiotherapist with 24 years of clinical experience in women’s health. This is not how abdominal exercises are typically performed in group fitness classes, online programs or home settings. The conditions that produced the findings do not reflect real-world practice, where form, load and supervision vary significantly.
- Study populations were narrow
Participants were generally healthy with specific inclusion criteria. Women with previous births, abdominal surgery, higher BMI, or existing pelvic floor dysfunction were largely excluded. These are the populations most commonly seeking guidance in clinical and fitness settings, and they were not represented.
While Theodorsen et al. (2024) did include women with existing DRA, finding no significant change in IRD in that group does not mean no impact occurred. It means the gap did not get measurably wider under supervised, controlled, moderate intensity conditions. Impact on pelvic floor function, linea alba quality, intra-abdominal pressure management and the woman’s functional capacity was not measured. The right population was included. The outcome measures were too narrow to detect the full picture.
- Diastasis changes naturally during pregnancy regardless of exercise
Both studies showed IRD increased in all groups during pregnancy. This is a normal physiological adaptation to accommodate the growing uterus. The baby has to go somewhere, and the abdominal wall separation is part of how the body makes space. Exercise was unlikely to prevent this structural change, which makes the null finding less informative than it appears.
- Long-term outcomes were not examined
The studies report outcomes to six weeks postpartum at most. We do not know whether different exercise approaches during pregnancy influence postpartum abdominal wall recovery, pelvic floor health, or longer-term musculoskeletal outcomes. Absence of short-term impact is not evidence of long-term safety.
- Absence of evidence is not evidence of absence
Conducting randomised controlled trials that deliberately expose pregnant women to potentially harmful exercise in order to measure impact is ethically problematic. This means certain questions will never be answered by the research design some demand. The absence of an RCT confirming impact does not mean impact does not occur. Where evidence is limited for ethical reasons, the precautionary principle applies. This is standard practice across pregnancy care and women’s health, and it underpins many current pregnancy exercise guidelines globally.
The abdominal canister, comprising the diaphragm, abdominal wall, pelvic floor and deep spinal muscles, functions as an integrated pressure system. This is not a contested model. It is the foundation of allied health, exercise and rehabilitation practice globally, supported by decades of biomechanical research. Our position is built on that foundation.
What the Research Does Not Address
There is a dimension entirely absent from both studies: the woman’s physical experience. In practice, women commonly describe discomfort, downward pressure, heaviness and a sense of instability during and after loaded rectus work in pregnancy. These are not incidental complaints. They are signals from a body under load, and they deserve to be treated as clinical information.
In the absence of research that measures the woman’s experience, clinical observation is a recognised and legitimate form of evidence. It is how many clinical patterns are first identified before formal research follows. Dismissing what women consistently report because it has not yet been formally studied is precisely the pattern that has left women’s health under-researched for decades. We name it here not as proof of impact but as a signal that warrants investigation.
WHEN supports women moving throughout pregnancy. This position is not about limiting exercise. It is about ensuring that women and the allied health and fitness professionals working with them make decisions based on the full picture, not a partial reading of the evidence. Telling a woman loaded rectus work is safe because IRD did not change in a 12-week supervised study is not respecting her autonomy. Women who understand the full system, not just the gap measurement, are better placed to make decisions about their own bodies.
WHEN's Recommendation
WHEN supports a whole-body approach to abdominal exercise during pregnancy. Our focus is on coordinated function of the abdominal wall, pelvic floor, breathing and connective tissues, taking into account the increasing demands on the body as pregnancy progresses. At this stage of the evidence, we would encourage caution around loaded rectus work as a routine part of antenatal exercise.
It is worth being clear about what the evidence actually shows. These studies found that IRD did not significantly change under specific, supervised conditions over 12 weeks. That is a valuable finding. It does not, however, constitute a finding that loaded rectus work is broadly safe during pregnancy. Safety is a much larger claim than a single outcome measure can support.
WHEN’s position is grounded in the full body of available knowledge, including biomechanical principles, clinical observation, and an honest acknowledgement of what the current research can and cannot tell us. Reasoning carefully in the presence of incomplete evidence is not a weakness. It is what responsible clinical practice looks like.
This statement will be reviewed and updated as new evidence emerges. It should be read alongside WHEN’s broader exercise and pregnancy guidelines, which address the full scope of movement during pregnancy. Nothing in this statement contradicts or supersedes those guidelines.
A Note on Scope
This is a position statement, not a clinical guideline. Its purpose is to articulate where WHEN stands on the current evidence and what we believe the evidence does and does not support. Specific practical guidance on exercise selection, load, trimester and individual assessment belongs in clinical guidelines, developed by qualified professionals working with individual women.
References and Supporting Documents
Full citations for the two randomised controlled trials referenced in this statement, and the broader evidence base underpinning WHEN’s position, are provided in the following three accompanying documents prepared for the Clinical Governance Committee:
- Backing Document: Diastasis Recti Abdominis in Pregnancy and Postpartum — summarises the current research evidence on DRA, including definition, prevalence, measurement limitations, exercise evidence, and the distinction between pregnancy and postpartum populations.
- Critical Appraisal: Cabral et al. (2025) — a balanced appraisal of the first trial, identifying what the study does and does not show and the gaps relevant to clinical practice guidance.
- Critical Appraisal: Theodorsen et al. (2024) — a balanced appraisal of the second trial, identifying what the study does and does not show and the gaps relevant to clinical practice guidance.
