Mathematics · Allostatic load · Stress response
Mathematics · The fast clock
What the body does after an event.
A marathon, a birth, a night flight and a week of sepsis are not the same object as four years of financial strain. Each row here is an event whose study measured a biomarker, run on that study’s own window.
A theoretical model with illustrative parameters. The curves are the model’s memory of the event, not the laboratory values. Nothing here is fitted to those assays, and it says nothing about any individual.
- Measured
- Clock
- Source
- What the curve is not
Memory of the event
Fast exposure follows the event’s own time constant. Slow memory follows the longer sampling window. Where the abstract gave no half-life, that slow tail is the window, not a fitted scar.
Demand from this event
Everyday demand is left off this axis, so the pulse is the event alone. On the year-scale allostatic load page, load and capacity are what accumulate. They barely move across an afternoon.
The sixteen events
| Event | Biomarker the study measured | Clock | PMID |
|---|---|---|---|
| marathon race | Cytokine panel for 4 h after the finish; ECG and heart-rate variability through the race and at 3 min | On for 4 h, followed for 2 days | 9925898, 24832192 |
| first-marathon training year | Cardiac MRI across 12 months in previously sedentary adults | On for 12 months, followed for 17.9 months | 25281664 |
| eastward long-haul flight | Salivary cortisol rhythm after a stay across 5–8 time zones | On for 2 weeks, followed for 5.1 weeks | 33543430 |
| long-haul cabin duty | Urinary melatonin peak and actigraphy, before the trip and on the first recovery day | On for 36 h, followed for 8 days | 36081186 |
| childbirth | 76 routine labs, from 20 weeks before conception to 80 weeks after, in about 300,000 pregnancies | On for 3 months, followed for 16.4 months | 40138427 |
| sport concussion | Blood GFAP, NfL, total tau, UCH-L1, and white-matter MRI in the CARE Consortium | On for 7 days, followed for 2.3 months | 37328299 |
| away competitive match | Salivary cortisol and testosterone, compared by home and away venue | On for 2 h, followed for 24 h | 28438635 |
| pre-symptomatic respiratory infection | Wearable heart rate and steps | On for 10 days, followed for 5.7 weeks | 34845389 |
| hospital shift | Electrodermal activity, heart rate and skin temperature across about one week | On for 7 days, followed for 3 weeks | 35650267 |
| sauna bout | NT-proBNP and other cardiovascular markers, before, immediately after, and 30 min later | On for 30 min, followed for 6 h | 29971466 |
| cold-water immersion | Plasma noradrenaline during 1 h of head-out immersion at 14 °C | On for 1 h, followed for 7.2 h | 8891513 |
| academic examination | Salivary IgA and chromogranin A; cortisol did not change significantly | On for 1 h, followed for 7.2 h | 18724010 |
| Antarctic posting | Salivary cortisol, IgA, IgM and TGF-β at departure, after a month at sea, and after a month at Maitri | On for 8.6 weeks, followed for 6.6 months | 24082460 |
| burn injury | Serum cortisol, CRP and immunoglobulins after the burn | On for 3 weeks, followed for 3.9 months | 21991143 |
| major surgery | IL-6, which the review reports rising in proportion to tissue trauma | On for 24 h, followed for 3.4 weeks | 21464062 |
| sepsis | Procalcitonin and CRP across the first week | On for 7 days, followed for 7 weeks | 26367532 |
Events shorter than half a year stay out of the chronic pile-up term. The first-marathon training year sits on that boundary. The same stressor can also build capacity when the dose is moderate and there is time to recover: growth or scarring.
What is not on this pane
SoccerMon, CARE on FITBIR, nuMoM2b and the open wearable deposits are places a kernel could be estimated. They are not extra potencies. Away-match cortisol and the Antarctic salivary panel had no direction in the abstract extract, so those curves are clocks only. The concussion half-life was not in the abstract.