biohacks
No Overhead Light After Sunset
After sunset, switch off overhead ceiling lights and use only low-mounted warm lamps. Overhead light enters the eye at the same angle as midday sun and tells the circadian system it is still daytime. Zero-cost, evidence: medium.
Vagus Nerve Humming — 3 min
Three minutes of long, low-pitched humming on the exhale stimulates the vagus nerve via the larynx and ear. Vagal stimulation, parasympathetic activation, a focus reset.
Time-Restricted Eating — 14:10 Window
Eat within a 10-hour window each day, fast for 14 hours. Gentler than 16:8 and easier to hold long-term, especially for women and high-training-volume athletes. Same mechanism, lower disruption risk.
Red Light Therapy 10 min
Ten minutes of 630–850 nm red / near-infrared light on bare skin from a 100–200 mW/cm² device, 3–5x/week. Modest skin and possible mitochondrial benefit; evidence stronger for skin than systemic.
Zone 2 + Lactate Test Calibration
Run or cycle 45 minutes at Zone 2, then finger-prick a lactate meter once a month — staying ≤2.0 mmol/L confirms the zone; skip it and most people drift into Zone 3.
Morning Sun — No Sunglasses, 10 Min
Skip sunglasses for the first 10 minutes of outdoor light each morning — eye-level light exposure, not the clock, is what anchors the circadian rhythm.
Sauna 4×20 min/week at 80 °C
Four 20-minute sauna sessions per week at 80–90 °C: heat-shock proteins, lower blood pressure, and cohort data on reduced cardiovascular mortality. Highest evidence-level heat protocol.
HRV — Morning Tracking
Sixty seconds of HRV on waking, tracked as a 7-day rolling average — an objective early signal of accumulated stress and under-recovery before performance drops.
CO2 Tolerance Test — Monthly
After a normal exhale, hold and time the first strong urge to inhale: under 20 s low, 20–40 s average, over 40 s high. Track monthly.
Glucose Spike Walking Rule
Walk 10–15 min within 30 min of any meal you expect to spike glucose. Consistently the largest free intervention for postprandial glucose.
Caffeine Cutoff 8 Hours Before Sleep
No caffeine within 8 hours of sleep. Its 5–6 h half-life means an afternoon coffee still occupies adenosine receptors at bedtime.
Bright-Light Box — Winter Mornings
A 10,000-lux light box for 20–30 min within an hour of waking is the best-supported intervention for winter seasonal mood dips.