飛脚 / HIKYAKU

Know before you add — the margins of 'normal' and the science of where you stand

Wed, 03 Jun 2026 00:00:00 +0000

There’s a moment when you open the envelope from your annual checkup. A column of numbers, reference ranges, the words “no findings of note.” In most cases, that piece of paper is filed away in a drawer and never opened again until next year’s envelope arrives.

But are the margins of that paper really empty? Within the “acceptable range” called the reference value, where exactly do you stand? A number sitting at the upper edge and a number near the ideal both read as “normal” on paper — yet ten years from now, they cast different shadows on your body.

On balance — what an acupuncturist in Barcelona saw through me

Wed, 27 May 2026 00:00:00 +0000

My current job is customer support — heavily tilted toward digital.

The customers who contact us work digitally too, and of course the inquiries are digital. Looking at my work from above, what I do reduces to two things: chatting with a PC, or talking on the phone through a PC. Nothing physical is produced. And truthfully, neither is anything produced by the people contacting us.

Is HbA1c 5.4% 'normal'? — Why precision nutrition targets ≤ 5.3%

Wed, 20 May 2026 00:00:00 +0000

You get a health checkup. “HbA1c 5.5%, within normal range.” You relax. Head home.

That’s the correct clinical judgment. But from the perspective of precision nutrition, 5.5% has already entered “watch” territory.

Clinical standards versus precision nutrition ideals

Marker	Clinical medicine	Precision nutrition
HbA1c normal	Under 5.7%	5.0–5.3%
HbA1c pre-diabetic	5.7–6.4%	Caution above 5.4%
Fasting glucose normal	Under 100 mg/dL	80–90 mg/dL

This gap stems from different measuring sticks.

Clinical standards are designed to determine the presence or absence of disease. The line exists to judge “diabetic or not.” Below 5.7% means no diabetes — medically correct.

How sound reaches the body — speakers, the vagus nerve, and the parasympathetic system

Wed, 13 May 2026 00:00:00 +0000

When choosing a speaker, most people look at specs. Frequency range, output, driver materials. That’s valid. But let’s think a little deeper about what those specs ultimately affect.

Sound is vibration in air. The speaker’s diaphragm pushes air, and those waves reach the eardrum. So far, this is physics. But beyond the eardrum lies neuroscience.

From the eardrum to the vagus nerve

Sound waves vibrate the eardrum and are converted to electrical signals in the cochlea. These signals travel via the auditory nerve to the brainstem.

When does illness begin?

Wed, 06 May 2026 00:00:00 +0000

My grandmother died of colon cancer.

She was past eighty and still looked healthy. Calligraphy, knitting, an active daily life. But at some point she began saying things like “I have no appetite” and “food doesn’t taste good anymore.”

She visited her local clinic regularly. But those visits had become routine — like going to school or work. The doctor processed them accordingly. To be fair, my grandmother herself described her symptoms as “just a cold” or “tired from age,” so the doctor can’t be blamed.

Your afternoon coffee and the adenosine receptors

Wed, 22 Apr 2026 00:00:00 +0000

What decides when you drink your coffee?

“First thing in the morning.” Most people do this. But from the perspective of precision nutrition and circadian rhythm, that first cup is likely consumed during the least effective window of the day.

The morning cortisol peak

Immediately after waking, your body autonomously surges cortisol production. This is called the CAR (Cortisol Awakening Response). It peaks 30–45 minutes after waking and gradually declines over the next two hours.

For those it reaches — on starting this blog

Wed, 15 Apr 2026 00:00:00 +0000

Starting a blog, now of all times.

Maybe it’s countercultural.

There was always something about social media that didn’t sit right. Reading the algorithm, maximizing engagement, crafting posts designed to perform — I couldn’t do it. Or more honestly, I didn’t want to.

In an era where every means of expression has been democratized and anyone can publish freely, there’s a strange confinement to the content produced inside these platforms. Recommendation algorithms optimized for “virality,” and posts designed to match them. The result is a structure where what spreads matters more than what’s actually valuable.