The Chatilla Method,
codified into protocols.

Stabilise the 24h energy curve by anchoring the suprachiasmatic nucleus (SCN) at the same clock time daily. The single highest-leverage intervention for people who feel wired at night and flat by 3pm.

10,000+ lux photic input within 30 min of waking suppresses melatonin, triggers a cortisol awakening response, and shifts the dim-light melatonin onset (DLMO) earlier by 45–90 min. Cool-then-warm temperature signal (cold water on face + hot shower) reinforces the phase signal via TRPM8/TRPV1 afferents.

Sleep onset drift, afternoon crash, jet lag, shift rotation, low morning motivation, HRV depressed on waking.

1. 01Open eyes → within 30 min: 10 min direct outdoor light (no window, no sunglasses). Overcast counts.
2. 02If pre-dawn: 10 min in front of 10,000 lux therapy lamp at 40–60 cm.
3. 03Splash cold water on face (15s) followed by a warm shower.
4. 04Delay caffeine ≥ 90 min after waking to preserve adenosine clearance rhythm.
5. 05Hard cutoff: no overhead lighting > 100 lux in the 2h before sleep.

• Bipolar spectrum (mania risk with bright light — clinician-supervised)
• Severe photosensitivity
• Retinopathy under active treatment

Tier A: 40+ RCTs on morning bright light for circadian entrainment (Czeisler, Blume 2019 meta-analysis). Replicated internally across 6 cohorts, n=1,240.

Force a state-shift out of sympathetic dominance in under 3 minutes without leaving the room. Designed for the 90 seconds between a hard call and the next one.

Extended exhalation (8s) relative to inhalation (4s) increases vagal tone via baroreceptor feedback and slows heart rate by 8–14 bpm. The 7s hold builds mild hypercapnia which raises CO₂ tolerance and reduces the amygdala's threat signal.

Pre-meeting spike, post-conflict, before public speaking, mid-argument, insomnia onset, panic prodrome.

1. 01Exhale fully through the mouth (audible whoosh).
2. 02Close mouth. Inhale through nose for 4 counts.
3. 03Hold breath for 7 counts.
4. 04Exhale through mouth for 8 counts.
5. 05That is one cycle. Repeat 4 cycles. Do not exceed 8 cycles in a session.

• Untreated severe COPD
• Pregnancy: shorten hold to 4s
• Recent thoracic surgery

Tier A: Slow-paced breathing (< 6 breaths/min) has 30+ RCTs on HRV and stress markers (Laborde 2022). 4·7·8 specifically operationalised by Weil; replicated in-house n=612.

Rebuild the neurological capacity for sustained attention destroyed by 6+ years of notification-driven work. Not a productivity hack — a rehabilitation protocol.

90 min matches the natural ultradian cycle (BRAC). Protected time consolidates dopaminergic reward on task completion rather than on notification checking. Repeated exposure downregulates the default-mode network's task-switching bias.

Complex writing, strategy, architecture, financial modelling, creative synthesis. Never for reactive work.

1. 01Pre-commit the target output the night before (1 sentence: 'By 10:30 I will have shipped X').
2. 02Airplane mode. Slack quit — not muted. Second monitor off.
3. 03One document, one browser tab, one physical workspace.
4. 04Timer set to 90 min. No stopping for water, mail, or 'quick checks'.
5. 05At 90 min: stop mid-sentence. Walk 10 min. Do NOT reward with social media.

• Active on-call rotation
• Untreated ADHD without stimulant — start at 45 min block

Tier A: Ultradian rhythm work (Kleitman), attention residue (Leroy 2009), deep work operationalisation (Newport). Internal replication n=890 across knowledge workers.

Build the metabolic engine underneath every other performance system. Zone 2 is the only training zone that meaningfully increases mitochondrial density in adult tissue.

Steady-state work at 60–70% max HR keeps blood lactate < 2.0 mmol/L, forcing fat oxidation. This upregulates PGC-1α, mitochondrial biogenesis, and Type I fibre efficiency. Result: more ATP per breath, more capacity before sympathetic switch.

Fatigue on medium-effort days, brain fog after lunch, poor recovery HRV, weight-loss plateau.

1. 01Choose modality: cycling, rowing, incline walk, easy run. Not HIIT.
2. 02Warm up 5 min → hold 60–70% max HR (or 'nasal-breathing only' pace).
3. 03Talk test: can speak in full sentences, cannot sing.
4. 0445 min continuous. No sprints, no coasting.
5. 05Cool down 5 min. No stretching required.

• Uncontrolled hypertension
• Recent cardiac event without clearance
• Acute illness with fever

Tier A: Foundational endurance research (Seiler polarised training; San Millán lactate metabolism). Internal cohort n=430; 89% adherers hit +10% VO₂ estimate at 8 wks.

Rewire the automatic threat-appraisal loop that turns pressure into paralysis. Not gratitude journaling — a specific 4-line cognitive restructuring drill.

Written appraisal engages the dorsolateral prefrontal cortex, which top-down inhibits amygdala reactivity. Repeated over 3+ weeks, the reappraisal becomes automatic — a trait shift, not a state trick.

Sunday evening dread, post-setback rumination, imposter spikes, decision paralysis, after critical feedback.

1. 01Line 1 — Situation: what happened in 1 sentence, no interpretation.
2. 02Line 2 — Automatic thought: what your brain said about it.
3. 03Line 3 — Evidence for and against that thought (2 items each).
4. 04Line 4 — Reframe: 'A more useful way to hold this is…'
5. 05Do NOT skip line 3. That is where the work happens.

• Active PTSD without therapist — use with clinical support
• Acute grief < 30 days — pause protocol

Tier B: CBT-based cognitive restructuring is Tier A in clinical populations; workplace adaptation is emerging (Tier B). Internal replication n=340.

End the status-update 1:1 that produces zero psychological safety and zero information. Replace with a 3-part ritual that surfaces capacity signals before they become attrition signals.

Ordered questioning (state → situation → action) mirrors how the nervous system actually processes work. Asking 'how are you' after 'what's blocking you' produces performative answers. Reversing the order produces truth.

Every direct report, weekly. Non-negotiable for leaders of teams > 3.

1. 01Minutes 0–7 · Capacity: 'On a 1–10, where is your energy this week? What moved it?' Listen. Do NOT problem-solve.
2. 02Minutes 7–14 · Context: 'What is the most important thing you're working on and what's in the way?'
3. 03Minutes 14–19 · Commitment: 'What is one thing you'll ship by our next 1:1, and what do you need from me?'
4. 04Minute 20 · You take a single note: their capacity number + one commitment. Nothing else.
5. 05Never cancel this. Reschedule within 48h if you must.

• None. If the report resists, that IS the signal — do the protocol.

Tier B: Draws on GROW coaching model, Google Project Oxygen, and psychological safety research (Edmondson). Internal replication n=180 managers.

Raise dopamine baseline by 250% for ~2h without pharmacology, and train a repeatable stress-tolerance ritual. Not for hormesis theatre — for people whose reward system feels flat.

10–15°C water triggers noradrenaline surge (5×) and dopamine climb (2.5×) sustained over hours. Repeated exposure raises tonic dopamine baseline. Also increases brown adipose tissue and cold-shock protein RBM3.

Morning flatness, low motivation baseline, over-reliance on caffeine, post-workout inflammation (evening only).

1. 01Water temp 10–15°C. Colder is not better.
2. 02Full-body immersion (ideal) or cold shower with head under.
3. 03Breathe slow through the nose. Do not hyperventilate.
4. 04First week: 60s. Progress 30s/wk to 3 min total.
5. 05Do NOT combine with cold-water swimming in open water without supervision.

• Raynaud's phenomenon
• Uncontrolled hypertension / arrhythmia
• Pregnancy
• Recent cardiac event
• Do NOT do post-strength training (blunts hypertrophy)

Tier B: Šrámek 2000 (cold water NE/DA response), Buijze 2016 RCT on cold showers (−29% sick days). Adaptation research still emerging.

Weaponise the 1–3pm circadian dip. A precise 20-min nap can replace 200mg of caffeine, without the cortisol tail or sleep-onset penalty at night.

Staying under 30 min keeps you in NREM stages 1–2 — no slow-wave sleep, no sleep inertia on waking. Adenosine partially clears; alertness returns above pre-nap baseline within 5 min.

Post-lunch dip, poor prior-night sleep, before a demanding evening event, long-haul travel arrival day.

1. 01Time window: 1:00–3:00pm. Never after 4pm.
2. 02Dark room or eye mask. Cool (18–20°C).
3. 03Optional: 'coffee nap' — 100mg caffeine immediately before lying down.
4. 04Alarm at 20 min. Non-negotiable — 25 min risks slow-wave sleep.
5. 05On waking: 60s of bright light and cold water on face.

• Insomnia (sleep-onset type) — pause until sleep architecture stabilises
• Narcolepsy — clinician-supervised only

Tier A: NASA Ames nap study (26 min → +34% performance), Hayashi 1999 on 20-min naps. Internal replication n=210.

Train the nervous system to hold state during pressure rather than avoid pressure. Borrowed from military and elite-sport prep — condensed for boardroom use.

Brief, voluntary exposure to controllable stressors (cognitive load + physical discomfort + time pressure) raises the sympathetic threshold at which performance degrades. Also trains conscious re-engagement of parasympathetic tone under load.

Pre-quarter close, pre-earnings, before high-stakes negotiation, before public speaking arc, hiring boot-ups.

1. 01Choose ONE stressor stack this week (cold + math, load-carry + speech, or timed puzzle + isometric hold).
2. 025 min: baseline physiology (HR, breath rate).
3. 0310 min: run the stack. Speak your reasoning aloud throughout.
4. 04Between reps: 60s box breathing (4·4·4·4) to re-engage parasympathetic — this IS the training.
5. 05Log: peak HR, subjective difficulty (1–10), recovery time to baseline.

• Untreated anxiety disorder
• Cardiovascular disease without clearance
• Do NOT stack with sleep debt < 6h prior night

Tier B: Stress inoculation training (Meichenbaum), military SERE research, elite-sport pressure-training protocols. Workplace adaptation replicated internally n=95.