Quick Answer
A bulging or heaviness feeling after a run, especially in the postpartum months, is common and does not automatically mean you have a significant prolapse. Research on postpartum exercise has found that starting general exercise early does not raise the risk of prolapse, and when prolapse is found in women training at high intensity, it is usually the mildest grade. What one sensation during a run cannot tell you is exactly what is happening in your body, since a symptom that only appears under exertion can be missed on a standard resting exam. Track when it happens and arrange an assessment, ideally one that can reproduce the feeling.
Something I hear often from women a few months into postnatal recovery is a version of the same story. The baby is a bit older, running feels like getting a piece of themselves back, and then halfway through a short, easy run, there it is. A pulling, dragging or bulging feeling low in the pelvis that was not there yesterday. The run gets cut short, the phone comes out, and the search starts: is this prolapse.
I want to answer that honestly rather than reassure you out of habit. A new sensation like this deserves a proper answer, not a guess in either direction.
A Bulge That Only Shows Up When You Run Is More Common Than It Feels
If you are picturing yourself as an outlier here, you are not. A 2026 study out of Cardiff Metropolitan University recruited postpartum runners who were already reporting pelvic floor symptoms during running, specifically to understand what was happening to their pelvis and their confidence while they ran (Donnelly et al., Frontiers in Sports and Active Living, 2026). It was a small, exploratory study, thirteen women, so it is early evidence rather than a settled answer. But the fact that researchers are actively studying exactly this pattern, bulging and heaviness symptoms that show up specifically during postpartum running, tells you something useful on its own: this is a real, recognised experience, not something unusual about your body.
That study also measured something worth naming directly, how much fear of experiencing symptoms affects a woman’s running. Fear is a completely reasonable response to a new sensation, but it is not the same thing as evidence that something has gone wrong.
Why a Bulge During Exercise Does Not Automatically Mean a Significant Prolapse
Here is the part that tends to get skipped in the worry spiral. A 2025 study compared women doing CrossFit against women doing other high-intensity training and measured prolapse directly using the clinical POP-Q scale, alongside the symptoms women reported themselves (Arbieto et al., Sports Health, 2025). Around four in ten women in both groups had some degree of prolapse on examination, and the most common finding by far, in both groups, was the mildest grade. High-intensity training did not push women towards more severe prolapse than any other demanding sport.
There is an even more direct answer for your actual question, which is about starting exercise again after birth specifically. A Norwegian cohort study followed women from six weeks postpartum, comparing those who had already returned to regular exercise with those who had not, then checked both groups again at twelve months for pelvic floor symptoms and prolapse (Tennfjord, Engh & Bø, Physical Therapy, 2020). Starting general exercise early made no measurable difference to prolapse or incontinence a year on. The researchers’ own conclusion was that first-time mothers should be encouraged to start exercising in the early postpartum weeks, not discouraged from it.
Getting back to running has not been shown to cause prolapse. A bulging sensation during a run is a symptom worth understanding properly, not evidence that movement itself is the problem. If you want the fuller picture of what prolapse actually is, how it is graded and what tends to help, my full guide to pelvic organ prolapse covers that in depth.
Your Pelvic Floor Is Still Settling at This Stage
Think of the tissue supporting your pelvic organs right now a bit like a trampoline that has just had its mat and springs replaced after years of heavy use. The frame is sound, but new springs need time and gradual loading to find their proper tension again. Put a hard, sudden bounce on it before that happens and it can feel like it is giving more than it actually is, even though nothing has failed.
That picture lines up with what a longitudinal study of pelvic organ support actually found. Researchers tracked first-time mothers with pelvic ultrasound from pregnancy through to a year after birth and found that most measures of pelvic organ support, after shifting during pregnancy and again around delivery, had recovered back towards their starting point by twelve months, particularly after vaginal birth (Reimers et al., BJOG, 2016). At five months, you are still inside that recovery window, not at the end of it.
This is a useful way to picture why exertion can feel different right now, but it cannot tell you whether one particular sensation reflects an established prolapse or tissue that is simply still finding its full strength. Only an assessment can tell you that.
What to Notice Before Your Next Run
None of the following is a diagnosis. It is the kind of pattern that genuinely helps a clinician, and it is worth noting down rather than trying to remember afterwards:
- Whether the feeling happens every run, or only occasionally
- Roughly when in the run it starts, early on or only after distance builds
- Whether it eases within a few minutes of stopping, or lingers for hours
- Whether it comes with leaking, dragging, pelvic pain, or a visible or palpable bulge
- Whether your bladder or bowel felt full beforehand, since a full bladder can itself create a temporary sense of pressure
Tracking this for even a week or two tells a clinician far more than “it felt like something was bulging” on its own.
Why a Standing or Post-Run Assessment Matters
If you are worried an assessment will miss what you actually feel because you will be lying flat on a couch, that worry has real clinical backing, and the guidance is explicit about it. NICE recommends that if a woman’s prolapse symptoms are not explained by a standard examination, the clinician should consider repeating that examination with her standing or squatting, or at a different time (NICE guideline NG123). The same guidance is clear that diagnosis is based on your history and a physical examination, not routine scans or imaging.
It is worth saying this plainly at your appointment rather than assuming it will come up on its own: tell your GP or pelvic health physiotherapist exactly when the feeling shows up, and ask whether it is possible to reproduce it, for example by standing, bearing down, or examining you shortly after activity rather than only at rest.
What Can Help While You Get This Checked
If an assessment does find a mild, symptomatic prolapse, NICE guidance sets out a clear first option, not surgery, but a supervised programme of pelvic floor muscle training lasting at least sixteen weeks for stage one or stage two prolapse (NICE guideline NG123). That is a genuinely encouraging starting point if this is where you land.
In my experience teaching Hypopressives, the breath and pressure-management coordination it builds supports exactly that kind of work. I am not going to tell you it has been tested against a running-specific bulge, because it has not, and I would rather be straight about that than oversell it. But the women I teach who have been properly assessed and told they have a mild, exertion-related prolapse often find that learning to manage intra-abdominal pressure well, rather than bracing hard or holding their breath through effort, changes how impact feels in daily movement, running included. It is support alongside assessment, not a substitute for it.
When to Seek Assessment
This guide is educational and cannot diagnose what you are feeling. The NHS’s own guidance on pelvic organ prolapse lists a lump or bulge in or around the vagina, heaviness, and leaking during exercise as reasons to see a GP, and the same applies here. Arrange an assessment with a GP or pelvic health physiotherapist if a bulging or heaviness feeling is new, keeps happening with the same activity, does not settle within a short time of resting, or comes with leaking, pelvic pain, a visible or palpable bulge, or any difficulty fully emptying your bladder or bowel. None of these on their own is an emergency, but all of them are a genuine reason to get checked rather than wait and see.
If you would like to understand what a structured, criteria-based return to running actually looks like before your next attempt, my full guide to returning to running postnatally walks through the readiness test postnatal physiotherapists actually use. You are welcome to start a free 14-day trial if you would like to learn Hypopressives properly from the beginning while you wait for your appointment.
Sources
- Donnelly GM, Coltman CE, Straker R, von Lieres Und Wilkau H, Brantner CL, Moore IS. Pelvic Compression Garments Alter Running Biomechanics, Perceived Support, and Fear of Symptoms in Postpartum Women With Pelvic Floor Dysfunction. Frontiers in Sports and Active Living, 2026.
- Arbieto ERM, Fukuda FS, Da Roza T, da Luz SCT. Pelvic Organ Prolapse Among Female CrossFitters and Non-CrossFitters: A Cross-Sectional Study. Sports Health, 2025.
- Tennfjord MK, Engh ME, Bø K. The Influence of Early Exercise Postpartum on Pelvic Floor Muscle Function and Prevalence of Pelvic Floor Dysfunction 12 Months Postpartum. Physical Therapy, 2020.
- Reimers C, Staer-Jensen J, Siafarikas F, Saltyte-Benth J, Bø K, Ellström Engh M. Change in Pelvic Organ Support During Pregnancy and the First Year Postpartum: A Longitudinal Study. BJOG, 2016.
- NICE. Urinary Incontinence and Pelvic Organ Prolapse in Women: Management (NG123).
- NHS. Pelvic Organ Prolapse.
