Somewhere around 2:47 a.m., your nervous system throws a wild internal rave — all lights, noise, and false alarms — and drags you out of deep sleep to negotiate with the toilet.

Again.

This isn’t aging.
This isn’t weak willpower.
And it’s usually not a bladder problem.

It’s a systems failure — fluid timing, kidney handling, nervous system tone, and sleep depth all colliding like drunk bats in a phone booth.

The good news: most cases don’t need pills, patches, or a urologist with a prescription pad twitching in his pocket. You need you to stop doing a few things and start doing a few boring, effective ones.

Let’s get clinical. Then let’s get weird.

Evening Fluid Restriction (The Boring One That Actually Works)

This is the part nobody wants to hear, which is usually how you know it’s true.

Reducing fluid intake in the hours before bed is a first-line clinical recommendation for nocturia, not influencer folklore or sleep-hygiene Pinterest nonsense (Hashim & Abrams, 2008; Weiss et al., 2011).

The common mistake is obsessing over how much fluid you drink instead of when you drink it.

What the data actually show is simple: the closer your last drink is to bedtime, the more likely you are to wake up and pee.

Shorter fluid-to-bed intervals are associated with higher nocturia frequency (Yasuda et al., 2017).

This is why conservative urology guidelines push evening fluid restriction before medication ever enters the conversation (Hashim & Abrams, 2008).

No hacks. No gadgets. Just timing.

In practice, stopping fluids about three hours before bed, front-loading hydration earlier in the day, and modestly increasing sodium intake at dinner often reduces nighttime urination dramatically.

For a surprising number of people, this alone ends the nightly bathroom pilgrimage.

Glycerol: The Strange, Effective, “Why the Hell Does This Work?” Option

Now we leave polite society.

Glycerol sounds like something you’d use to preserve a reptile in a jar, but physiologically it’s been studied in humans for decades.

The key point is not controversial: glycerol increases fluid retention and reduces urine output compared to water alone.

This phenomenon is known as glycerol-induced hyperhydration and has been repeatedly demonstrated in controlled human studies (Freund et al., 1995; Goulet, 2007).

Mechanistically, glycerol raises osmotic pressure and pulls water into tissues — intracellular and extracellular — instead of letting it slosh around in circulation waiting to be filtered out by the kidneys. The result is lower urine volume over several hours (Freund et al., 1995; van Rosendal & Noakes, 2010).

Important honesty clause: there are no trials testing glycerol specifically for nocturia...

...but the renal effects are well documented - at least in my M3 1-1 clients and follow up to consult calls.

This is applied physiology, not moon magic.

In practice, one tablespoon of glycerol taken about 30–60 minutes before bed, tested for several nights, often reduces nighttime awakenings — not because urine production stops, but because fluid stops ending up in the wrong place at the wrong time.

Hat tip to Coach Rob Regish for this one.

Make sure if you do this, use food grade glycerol. I use the NOW brand version. Plus it is dirt cheap to boot.

Down-Regulation, Sleep Depth, and the Nervous System Trap

This is where people get led astray by oversimplified nervous system slogans.

Here’s the part that gets butchered online: parasympathetic activation directly triggers bladder emptying, while sympathetic tone supports bladder storage.

So no — “just turn on your parasympathetic nervous system” is not a direct anti-peeing strategy. Anyone saying otherwise skipped neurophysiology.

But that’s not the whole story.

Healthy sleep is defined by parasympathetic dominance paired with low sympathetic arousal.

When sympathetic tone stays elevated at night — stress, cortisol, mental overdrive — sleep becomes lighter, arousal thresholds drop, and minor bodily sensations get promoted to emergency alerts.

Including bladder signals.

This is why sleep disturbance and nocturia chase each other in circles (Weiss et al., 2011).

Autonomic imbalance also shows up repeatedly in lower urinary tract symptom frameworks, where sensory signaling and inhibition are dysregulated (Van Kerrebroeck et al., 2002).

Down-regulation does not stop urine production.
It stops unnecessary awakenings.

Clinically, the most common report is blunt and revealing:
​“I still had urine in my bladder — I just didn’t wake up for it.”

That distinction matters.

Anything that reduces evening hyper-arousal and deepens sleep can help: slow breathing with extended exhales, easy walks that don’t turn into performance art, and parasympathetic-leaning recovery work.

I personally love tools like the Shiftwave chair because it reduce nervous system hyper-vigilance and raises the threshold for waking up to every internal whisper.

Longer or deeper evening Shiftwave sessions aimed at down-regulation consistently align with fewer nighttime awakenings in real humans.

Again, you don't need a super fancy device per se, just do some longer exhales, short easy walk, chill, or some form of down regulation.

Putting It All Together (The Non-Sexy Experiment)

If nighttime urination is wrecking your sleep, try this for five to seven nights:

Stop fluids three hours before bed.
Add a touch more sodium at dinner.
Down-regulate aggressively in the evening — breathing, walking, or Shiftwave if you have one.
Optionally, add one tablespoon of glycerol before bed.

Track awakenings, urgency, and sleep quality.

Low risk. High signal.

Final Reality Check

No, there are no massive randomized trials isolating each of these variables...

..but every intervention here is mechanistically sound, supported by human data or clinical guidelines, used in real practice, and unlikely to interfere with anything else you’re doing.

This is what applied physiology looks like when it’s sober, armed, and unsentimental.

Complex stacked physiology made simple.

Sleep well,

Much love,

Dr MIke
PS - I have been using the Shiftwave chair now for almost 4 months and I love it for down regulation - which I am not the best with overall. Check out the full podcast I did with Dr Jeff there if you missed it HERE.
​Note- I am an affiliate for Shiftwave.

References

Freund, B. J., Montain, S. J., Young, A. J., Sawka, M. N., DeLuca, J. P., Pandolf, K. B., & Valeri, C. R. (1995). Glycerol hyperhydration: Hormonal, renal, and vascular fluid responses to glycerol ingestion. Journal of Applied Physiology, 79(6), 2069–2077.

Goulet, E. D. B. (2007). A meta-analysis of the effects of glycerol-induced hyperhydration on fluid retention and endurance performance. International Journal of Sport Nutrition and Exercise Metabolism, 17(4), 391–410.

van Rosendal, S. P., & Noakes, T. D. (2010). Guidelines for glycerol use in hyperhydration and rehydration. Sports Medicine, 40(5), 405–424.

Hashim, H., & Abrams, P. (2008). Nocturia: A guide to assessment and management. BMJ, 336(7634), 102–106.

Weiss, J. P., Blaivas, J. G., Bliwise, D. L., Dmochowski, R. R., & Rosenberg, M. T. (2011). Nocturia: Consequences, classification, and management. International Journal of Clinical Practice, 65(5), 491–498.

Yasuda, K., Nakai, Y., Tanaka, H., et al. (2017). Association between fluid intake before bedtime and nocturia in community-dwelling adults. International Journal of Urology, 24(9), 668–673.

Van Kerrebroeck, P., Abrams, P., Chaikin, D., et al. (2002). The standardisation of terminology in nocturia. Neurourology and Urodynamics, 21(2), 179–183.

_____________________

Mike T Nelson CISSN, CSCS, MSME, PhD
Associate Professor, Carrick Institute
Owner, Extreme Human Performance, LLC
Editorial Board Member, STRONG Fitness Mag
​​Mike T Nelson is a Ph.D. and not a physician or registered dietitian. The contents of this email should not be taken as medical advice. It is not intended to diagnose, treat, cure, or prevent any health problem - nor is it intended to replace the advice of a physician. Always consult your physician or qualified health professional on any matters regarding your health.

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