Why “Good Therapies” Sometimes Feel Inconsistent

Modern wellness is very focused on what to do:

•  ​Red light​ 
•  ​Cold therapy​ 
•  ​Vibration plates​ 
•  ​Sauna​ 
•  ​Hydrogen​ 
•  ​Exercise​ 

And here's something important to understand:

Many of these tools work even when timing isn’t ideal , and people absolutely still see benefits.

However - your biology doesn’t operate in a vacuum, and every single cell and organ system in your body has a circadian clock in front of it.....

Which means: Nearly every system involved in metabolism and recovery - cortisol, melatonin, mitochondrial respiration, glucose handling, autonomic tone, body temperature - follows a circadian rhythm coordinated by the suprachiasmatic nucleus (SCN) and peripheral clocks throughout the body.

So while poor timing doesn’t make a therapy “bad," better timing can make the same tool work more efficiently with your biology & nervous system.

That’s the lens of this article.....(keep reading for all the science & practical application)

Still time to shop before Christmas:  ​Updated gift guide​ - ​Gift Guide for Him​ & ​Regular Amazon Gift Guide for stocking stuffers​ 

🚨 Holiday sale is open now - ​Click here to save up to 60%​ . If you are a practitioner & want to sharpen your lens before the new year (and have a tax write off for your business) - ​Click here for the Leptin Master Plan​ & ​Check out the MyCircadianApp Practitioner Program​ 

 

Foundational Science: Why Timing Changes the Magnitude, Not the Validity (in other words - don't let perfect be the enemy of good)

Decades of circadian research consistently show:

• Mitochondrial respiration, redox state, and ATP production oscillate across the day.
• Cortisol naturally peaks in the morning and should decline into evening.
• Melatonin rises at night and is exquisitely sensitive to light, temperature, and sympathetic activation.
• Core body temperature peaks in late afternoon and must fall for sleep onset.

When inputs line up with these rhythms, the signal is amplified.

When they don’t, the signal isn’t erased - it’s just potentially less coherent.

This is one reason why two people can use the same tool and report totally different outcomes.

Core references:

 ​Panda S. The Circadian Code (2018)​ 

 ​Bass & Lazar. Circadian time signatures of fitness and disease.Science,​ 

 ​Zhang et al. Circadian clock regulation of metabolism.Cell, 2014​ 

 ​Czeisler et al. Circadian and sleep-dependent regulation of hormone release.JCEM​ 

 ​Vibration Plates​ & ​Rebounders,​ 

I have hyperlinked the exact brands that I personally use & recommend.

 ​Vibration therapy​ & ​Rebounding​ can both be beneficial at many times of day, especially for circulation, lymphatic movement, and muscle activation.

What research shows WBV activates:

• Muscle spindles

• Sympathetic nervous system

• Glucose uptake

• Mitochondrial biogenesis pathways (AMPK, PGC-1α)

Documented benefits include improvements in:

• Insulin sensitivity

• Neuromuscular signaling

• Balance

• Circulation

Key reviews:

•​ Rauch et al., Sports Med, 2010​ 

• ​Olivares et al., Int J Mol Sci, 2022​ 

• ​Lau et al., Diabetes Metab Res Rev​ 

Circadian optimization for ​vibration​ and ​rebounding​ (not requirement):

Because WBV & rebounding are both metabolically and neurologically activating, they tend to align best earlier in the day - morning to early afternoon when:

• cortisol is naturally higher

• sympathetic activation is appropriate

• body temperature is rising

For many people, using these tools late at night can:

• increase catecholamines

• delay melatonin onset

• fragment sleep

That doesn’t mean these tools “don't work, but it does mean that timing can change the outcome.

Now - the nuance.

Some people do find low-intensity vibration calming before bed. That doesn’t contradict the science, before ultimately - biology is state-dependent.

For individuals who are chronically stressed, tense, inflamed, or sympathetically dominant, gentle vibration can act as a regulatory input, similar to massage or rocking.

Same tool. Different nervous system. Different result.

Another quick note:

There’s a lot of online discussion claiming vibration “activates histamine” or “dysregulates the nervous system.”

In reality, responses to vibration - like exercise, sauna, or cold - are state-dependent.

People with mast cell disorders, severe histamine intolerance, or chronic inflammatory conditions may need to be more cautious with intensity and timing.

That doesn’t make vibration harmful - it makes individual physiology relevant.

Circadian-aligned is about matching the right stimulus to the right time of day for your biology.

If you want my personal protocol - ​click here to get access on Substack ​ 

Bottom line - If you want to optimize these, move them earlier, but if you don't have time in the morning - just try to keep it couple hours away from bedtime.

Exercise:

One of the most helpful papers I’ve read on circadian timing is a ​2019 Journal of Physiology study ​that mapped what’s called a phase–response curve for exercise.

In plain English: it asked…If you do the same workout at different times of day, does it shift your internal clock earlier or later?

Exercise is a time cue (a zeitgeber) - meaning it can act like a signal to your brain and body that says: this is when day happens.

In this study, researchers had adults do 1 hour of moderate exercise at one set time each day for 3 days (they tested multiple times across the 24-hour day). Then they tracked melatonin timing using urinary aMT6s (a reliable metabolite marker used to estimate melatonin rhythm timing).

Here’s the key takeaway:

• Exercise between ~7:00pm -10:00 pm tended to create larger phase delays (shifting the clock later)

• Exercise around ~7:00 am and ~1:00 - 4:00 pm tended to create larger phase advances (shifting the clock earlier & providing better sleep outcomes)

• Certain windows had minimal shifting & better sleep outcomes, suggesting timing matters if you’re trying to protect sleep/circadian rhythm

What that means for you:

If someone already struggles with “tired but wired,” insomnia, or delayed sleep… a hard workout in the evening can potentially nudge their clock later.

And if someone is trying to strengthen circadian rhythm, improve morning energy, or stabilize sleep timing, morning or early afternoon training tends to be the safest bet from a circadian perspective.

Important: this isn’t about being perfect.....working out & getting movement is almost always better than not.

Plenty of people exercise at night and do fine, and sometimes evening workouts are the only time life allows - AND the benefit of movement still matters. This is just the “mitochondria + circadian biology” lens: timing can change the outcome of sleep & recovery.

Important nuance:

Fasted morning workouts can backfire if you are already under a lot of stress, and I always recommend hydrating & eating 15g of protein + fat to stabilize blood sugar.

It's really not ideal to exercise before sunrise, but if that's the only time you have - I prefer mornings over evenings & recommend ​yellow blue blockers ​& covering your skin if under blue light (and then getting real sunlight and a more substantial breakfast when you are done).

Red Light Therapy (Photobiomodulation)

Photobiomodulation (PBM) is one of the most researched therapies in modern medicine, with over 10,000 peer-reviewed papers.

 ​Click here for my panel​ & I have also been LOVING ​this light ​(it's full of some beautiful red & infrared - use code SARAHK)

It influences:

• Cytochrome-c-oxidase

• ATP production

• Nitric oxide signaling

• Inflammatory pathways

Foundational researchers:

 ​Hamblin MR​ 

 ​Karu TI​ 

 ​Dr. Glenn Jeffery’s work ​suggests morning red/NIR light may pack a very powerful punch:

• Improving mitochondrial efficiency

• Supporting retinal-brain signaling

• Strengthening circadian entrainment

But here’s the key point:

 ​PBM can support sleep ​in some contexts and ​disrupt it in others,​ and there are actually some studies that show sleep improvement when done close to bedtime.

Timing, wavelength, dose, and individual sensitivity all matter, and I think we go back to the point I made about vibration therapy again: biology is state-dependent.

Morning or early day is generally the least disruptive & shows immense benefits for the mitochondria & eyesight (my personal favorite is right after sunrise).

Evening use isn’t “wrong” - it’s just more individual-dependent, and it's important to see how it impacts your sleep.

I personally have sleep disturbances if I try to do red light therapy too close to bedtime.

My husband - on the other hand - can do red light therapy right before bed and fall asleep within 5 minutes of getting in bed.

Cold Therapy

 ​Click here to get 40% off my cold therapy course​ 

Cold exposure:

• Activates sympathetic tone

• Increases norepinephrine

• Improves insulin sensitivity

• Enhances mitochondrial uncoupling

Key research:

 ​Tipton et al., J Physiol​ 

 ​Hanssen et al., Diabetes​ 

Best earlier in the day for most people.

Late-night cold can increase alertness and delay sleep - especially in wired-tired phenotypes.

If you want more practical application - I expanded on how I use cold therapy strategically (and give my cold therapy protocol) over on ​substack​ - as I am an H2 ​haplotype​ living on the 33rd latitude, and my mitochondria weren't necessarily meant to live this far south.

Sauna

 ​Click here for my sauna & save up to $2,200 with code SARAHK​ 

Heat exposure increases:

• Heat shock proteins

• Growth hormone

• Cardiovascular conditioning

Strong evidence:

 ​Laukkanen et al., JAMA Internal Medicine​ 

Most optimal circadian window:

Afternoon to early evening. Why?

Body temperature is naturally rising and peaks late afternoon

Your core body temperature follows a circadian rhythm:

• Lowest: ~4–6 am
• Rising: late morning → afternoon
• Peak: ~4–7 pm
• Decline: evening → night (required for sleep)

Sauna adds heat stress, and doing it while temperature is already rising or near peak means:

• Less physiological resistance
• Faster heat adaptation
• Stronger hormetic response (HSPs, circulation, mitochondrial signaling)

Doing sauna too late at night fights the required temperature drop needed for sleep, and Melatonin depends on the cool-down.

Now - sauna itself does not raise melatonin, but what helps melatonin:

• Post-heat cooling
• Temperature gradient (hot → cool → dark)

Early afternoon/evening sauna allows:

• Heat exposure
• Adequate time to cool down
• Melatonin to rise naturally later

Late-night sauna:

• Keeps core temp elevated too close to bedtime
• Blunts melatonin amplitude
• Can fragment sleep even if you “pass out”

The sweet spot (for most people)

1–6 pm, with an ideal target around 3–5 pm

If sauna is your only option at night:

• Keep sessions shorter
• Finish at least 2–3 hours before bed
• Emphasize post-sauna cooling (cool shower, cold air, dark room)

And if you can only do sauna in the morning - wait until after you have seen sunrise & been outside to reinforce your natural rhythm (remember: Temperature is a zeitgeber).

Hydrogen (Inhalation or Water)

 ​Click here for the hydrogen therapy I use ​(use code SARAHK for their holiday sale)

Hydrogen acts as a signaling molecule, not a blanket antioxidant.

There are over 2,000 studies on therapeutic hydrogen showing it can:

• Modulate inflammation

• Influence redox signaling

• Affect autonomic balance

Key reviews:

 ​Ohsawa et al., Nature Medicine​ 

 ​Ichihara et al., Medical Gas Research​ 

Circadian nuance:

 ​Hydrogen water​ tends to be gentler and more flexible with timing, while inhalation is more timing-sensitive. Something important to understand is that hydrogen doesn’t push the body toward sleep or energy - it supports redox normalization, and your circadian biology decides what that feels like in the moment.

 ​Hydrogen​ doesn’t act like a stimulant or a sedative - it acts as a redox signaling molecule. That means it doesn’t force the nervous system in one direction. It helps normalize mitochondrial and autonomic signaling, and your circadian state determines how that feels.

For most people, the most reliable window is late morning to early afternoon for inhalation (which acts quickly and systemically). Cortisol is naturally declining but still present, mitochondrial electron flow is high, and any energizing effect supports daytime physiology rather than interfering with sleep.

Some people feel calmer using ​hydrogen inhalation ​in the evening, particularly if nighttime cortisol is elevated and they feel “tired but wired.” Others feel more alert or even wired - not because hydrogen is stimulating, but because improving redox efficiency can increase alertness when circadian rhythms are already flattened.

My personal use: I expanded on my personal hydrogen protocols for myself, my daughter & my husband ​here​.

Magnesium baths:

 ​Click here for the magnesium soak I use​ 

A magnesium bath can be great before bed when it supports the natural drop in core body temperature that triggers sleep. The key is keeping the water warm, not excessively hot.

Excessive heat too close to bedtime can delay cooling and interfere with melatonin signaling, while a warm bath followed by a cool-down can enhance relaxation, parasympathetic tone, and sleep onset.

Science note: Sleep onset is driven by a decline in core body temperature and parasympathetic dominance, not heat itself.

Grounding:

(Grounding to the earth is always best - but ​this is the company I trust for grounding tools)​ 

Grounding works differently, as it’s helpful at any time of day by supporting circadian regulation rather than pushing stimulation or sedation.

By improving electrical balance and reducing excess sympathetic charge, grounding reinforces rhythmic signaling between the nervous system, the earth, and the circadian clock - making it one of the most universally tolerated tools across phenotypes and seasons.

Science note: Direct contact with the Earth can influence autonomic balance and circadian stability via electrical charge transfer.

Final Takeaway:

Circadian-aligned therapy is not about doing everything perfectly

It’s about:

• Direction over rigidity
• Timing over intensity
• Understanding your nervous system tone
• Respecting mitochondrial rhythms
• Allowing individual variability

Many tools work regardless, but some really do work better with timing.

I hope you found this helpful & informative (and not too overwhelming)!

Everything above is the reasoning behind why I approach these tools for myself & with clients, and if you want the HOW - ​click here​ to read over on subtack.

And if you love this sort of information, and want to apply it in your personal practice - ​click here for The Leptin Master Plan ​- specifically for advanced learners & practitioners.

 

 ​NEW PODCAST: Beyond Placebo - How Quantum Frequencies Interact with Your Biology (with Todd, LeelaQ)​ 

 ​FREE WEBINAR ON CIRCADIAN HEALTH - CLICK HERE TO WATCH THE REPLAY​ 

Please feel free to forward this to a friend or family member!

Enjoy my work & want to support me? (No pressure as this newsletter will remain free) Leave me a tip!

Reading this on the web or forwarded from a a friend? ​Click here to subscribe ​so you don't miss free informative content in the future.

Enjoy my work & want to support me? (No pressure as this newsletter will remain free) Leave me a tip!

$5.00 Sarah's tip jar Enjoy my work and want to support me? Leave me a tip! Thank you so much for your consideration ❤️ Send a tip

 

In Health🌞,

Sarah