The Performance Bridge

Sleep-deprived executives exhibit a 1.5 SD drop in leadership scores and a 2.97pp increase in loan default decisions (Iowa Gambling Task). The prefrontal cortex — your brain's CEO — is the first to suffer from sleep debt.

Companies led by "fit" CEOs (Limbach & Sonnenburg, S&P 1500 study) have firm values 4-5% higher. The effect is strongest in high-stress, high-M&A environments — fitness buffers cognitive degradation under pressure.

NBER research proves that working 3-6 months longer equals 1% more savings for 30 years. UK Biobank data shows optimal habits extend healthy years by 9.45 years — potentially doubling terminal wealth.

The U.S. loses $411 billion annually from insufficient sleep (RAND Europe). Workers sleeping <6 hours lose 6+ productive days per year. Cortisol dysregulation from chronic stress degrades every knowledge worker metric.

Sharpe's Arithmetic proves that fee reduction is the only guaranteed way to improve expected returns. A 1% fee can consume 30% of lifetime gains. Most investors suffer from "fee blindness" — they don't know what they pay.

Sitting >8 hours/day increases mortality risk by 59% (Ekelund, Lancet, N=1M). LPL enzyme activity drops 90-95% within hours of inactivity. The top 10% most productive workers use a 52-min work / 17-min break rhythm (DeskTime). Movement snacks blunt postprandial glucose by 24-30%.

Coates (Cambridge) found morning testosterone predicts day's P&L with Cohen's d = 1.37. Sleep-deprived traders show elevated gain expectations with muted loss sensitivity (Venkatraman, Duke). The cortisol/testosterone ratio is the closest thing to a biological P&L predictor.