Stress Urinary Incontinence: Why You Leak When You Run, Laugh or Jump

If you’ve ever leaked urine while running, jumping, coughing, sneezing or laughing — you’re not broken, weak, or “past your prime”.

You’re experiencing stress urinary incontinence (SUI).
And despite how common it is, it’s still wildly misunderstood.

Let’s break down what SUI actually is and why it happens.

What is Stress Urinary Incontinence (SUI)?

Stress urinary incontinence is involuntary leakage of urine during physical effort or impact.

Common triggers include:

  • Running, jumping, hopping

  • Coughing or sneezing

  • Laughing

  • Lifting weights

  • High-impact exercise

Despite the name, this has nothing to do with emotional stress.
The “stress” refers to physical pressure — specifically intra-abdominal pressure — pushing down onto the bladder.

Many women first notice SUI:

  • During pregnancy

  • After childbirth (yes, even after a caesarean)

  • When returning to impact exercise

  • At certain points in their menstrual cycle

  • When training load or fatigue increases

The Pelvic “Plumbing”: How Continence Actually Works

Think of your pelvis as a layered support system, not a single muscle doing all the work.

Here’s what’s involved:

  • Bladder – stores urine

  • Urethra – the tube urine passes through

  • Urethral closure system – sphincter muscles + a soft tissue “seal” that keeps urine in

  • Pelvic floor muscles – provide active support and respond quickly to pressure

  • Fascia and connective tissue – a passive “hammock” behind the bladder and urethra

  • Nearby structures – vagina, uterus and rectum all sharing space and load

Leakage tends to occur when pressure hits suddenly and the system can’t keep the urethra closed in that moment.

The Core Concept: Pressure vs Closure

To understand SUI, you need to understand the relationship between two competing forces.

1. Pressure inside the bladder

Your bladder is excellent at stretching and holding urine with minimal pressure changes — until you cough, jump or land.

Those actions cause a rapid spike of downward pressure.

2. Pressure keeping the urethra closed

At rest, the urethra stays closed thanks to:

  • Urethral sphincter muscle tone

  • The soft tissue “seal” of the urethral lining

  • Blood flow that cushions the closure

  • Support from pelvic floor muscles

  • Firm backing from connective tissue (fascia)

Leakage occurs when bladder pressure exceeds closure pressure, even briefly.

The “Backstop” Analogy (Why Support Matters)

Imagine stepping on a garden hose.

  • Hose on a hard floor? It closes instantly.

  • Hose on a trampoline? It bends, sinks… and water keeps flowing.

In the pelvis, the urethra relies on firm support behind it to compress shut when pressure hits.

If the connective tissue support behaves more like a trampoline — too flexible, fatigued or under strain — the urethra doesn’t seal effectively, and leakage occurs.

Why SUI Can Happen After Birth — Even With a C-Section

Stress urinary incontinence is not just about vaginal birth.

Pregnancy alone can contribute due to:

  • Prolonged load on pelvic floor muscles and fascia

  • Hormonal changes affecting tissue elasticity

  • Changes in posture and breathing mechanics

  • Altered pressure strategies through the abdomen

  • Nerve and muscle changes that may only show up under higher loads later

A history of:

  • Instrumental birth (forceps)

  • Long pushing stage

  • Significant perineal tearing

…can also influence pelvic floor function over time.

And here’s the kicker:
You can feel completely fine in daily life, and only leak when you add impact, fatigue or intensity.

Why Leakage Might Start 10 Minutes Into a Run

This is one of the most common patterns we see.

It usually points to fatigue and load accumulation:

  • The pelvic floor and closure system cope initially

  • Repeated impact slows reaction time

  • Muscles fatigue

  • Breathing or bracing strategies change

  • Fascia comes under increasing strain

The system compensates… until it can’t.

That’s why leakage can feel:

  • Delayed

  • Inconsistent

  • Worse at the end of sessions

  • Absent on some days but not others

Why It Can Be Worse Before Your Period

Hormones matter — especially for connective tissue.

In the late luteal phase (the week before your period), hormonal shifts can make connective tissue:

  • More pliable

  • Slightly less stiff

  • Less effective as a firm backstop

If your support system becomes more “springy”, the urethra may not compress as effectively during impact — even if you’re otherwise dry the rest of the month.

Why Emptying Your Bladder Doesn’t Always Fix It

Two important truths:

  1. Your kidneys never stop making urine
    Even if you pee right before exercise, small volumes can still leak.

  2. Small leaks feel big
    Just a few teaspoons can soak underwear and feel dramatic — even though it’s a tiny fraction of bladder capacity.

Stress Incontinence vs Urgency (They’re Not the Same)

Many women experience a mix of symptoms.

Stress urinary incontinence

  • Leakage with cough, sneeze, running, lifting, jumping

Urgency

  • A sudden “I need to go now” sensation

  • You may or may not leak on the way

They involve different mechanisms — and both are treatable.

What a Pelvic Health Assessment Looks For

When assessing SUI, pelvic health physiotherapists usually explore two main contributors:

A) Tissue support and movement (the backstop)

  • How much do tissues move under pressure?

  • What happens in standing, coughing or impact-like tasks?

B) Closure system and muscle response

  • Can the urethral sphincters stop urine flow quickly?

  • Can pelvic floor muscles:

    • Contract and relax well?

    • Sustain endurance?

    • Respond fast to sudden pressure?

Because not all leaks are caused by the same thing, identifying the main driver is key to effective management.

A Helpful Concept Check: The Tampon Test

A tampon (used only as a temporary test, not a treatment) can sometimes act as an artificial backstop.

If leakage improves when running with a tampon in place, it suggests support behind the urethra is a significant factor. This can help guide options like:

  • Targeted pelvic floor rehab

  • Load management

  • Breathing and pressure strategies

  • Temporary support devices for higher-impact activities

Key Takeaways

  • Stress urinary incontinence is caused by a mismatch between pressure spikes and urethral closure/support

  • It often appears “suddenly” with increased impact, fatigue or hormonal shifts

  • Small leaks can feel big — but they’re still meaningful

  • Effective management usually combines:

    • Pelvic floor and sphincter strength, endurance and timing

    • Smarter pressure strategies during exercise

    • Load modification and return-to-impact planning

    • Sometimes temporary mechanical support

And most importantly:
Leaking is common — but it is not something you just have to live with.

Book a consultation today to get the support that you need.

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