Blog
Recovery between workouts: what science says about rest days
Learn why recovery is when real fitness gains happen, how many rest days you need by training type, and how to use HRV, sleep, and nutrition to recover faster between workouts.
Sleep and longevity: the complete science-based guide
How sleep affects biological aging, lifespan, and healthspan. A comprehensive guide covering sleep stages, the U-curve of sleep duration, circadian biology, and evidence-based optimization strategies.
How accurate is sleep tracking on your wearable? What validation studies reveal
Are Apple Watch and wearable sleep trackers accurate? We analyze polysomnography validation studies to show what your device gets right — and wrong.
Chronic stress and epigenetic aging: how trauma writes into DNA
Chronic stress is linked with faster epigenetic aging through cortisol, inflammation, and DNA methylation. Learn what trauma studies show and what can help.
Blue light and circadian disruption: How screens are aging you at night
Blue light at night can suppress melatonin, shift circadian timing, disrupt sleep, and affect metabolic health. Learn the evidence and fixes.
Heart rate recovery after 60 seconds: The deep dive into autonomic aging
New research shows that the first 10-60 seconds after exercise reveal your autonomic age. Learn what each recovery window means, why vagal tone declines, and advanced strategies to improve HRR.
Cortisol awakening response: What your morning stress spike reveals about aging
The cortisol awakening response shows how morning cortisol rises after waking. Learn normal CAR patterns, testing limits, stress links, and practical habits.
Progesterone, sleep, and aging: The forgotten hormone
Progesterone declines years before menopause, disrupting sleep and accelerating aging. Learn how this neurosteroid works, why 60% of perimenopausal women can't sleep, and what helps.
Sleep and memory: How your brain consolidates memories at night
Discover how sleep supports memory consolidation — and why age-related sleep changes can impair this process. Learn strategies to improve sleep for better memory and cognitive health.