Blog
Sleep apnea: The silent condition that can accelerate biological aging
Untreated sleep apnea is linked to higher mortality risk and faster biological-aging signals. Learn the warning signs, how it damages your body at the cellular level, and evidence-based treatment options.
Training readiness score: How to know if your body is ready to train
Learn what a training readiness score is, how it's calculated from HRV, sleep, and recovery data, and how to use it to train smarter every day.
How many active calories should you burn per day?
Learn how many active calories you should burn daily for health, weight loss, and fitness goals. Understand BMR, TDEE, NEAT, and how to track your energy output.
Body temperature and sleep: How the circadian curve controls your rest
Learn how body temperature shapes sleep, why the circadian cooling curve matters, and which room, bath, and light habits support deeper rest.
Chronotypes and longevity: Are night owls really dying sooner?
Learn how chronotype, sleep timing, and social jetlag affect longevity risk, why night owls are not doomed, and how to align sleep, light, and recovery.
Flights climbed meaning: what Apple Watch really counts
Flights climbed meaning: one flight is about 10 ft (3 m) of elevation. Learn what Apple Watch counts, why stairs matter, and daily targets you can use.
Sleep debt: Can you actually pay it back? What science says
Is sleep debt real, and can you catch up on lost sleep? Learn what current research says about recovery sleep, weekend catch-up, health risk, and timing.
Training load curve: How to train smarter without overtraining
Learn what training load is, how the training load curve works, and how to use ATL, CTL, and TSB to optimize your workouts and prevent injuries.
Training load focus: How to balance your workout intensity zones
Learn what training load focus is, how to balance low aerobic, high aerobic, and anaerobic training for optimal fitness, and why intensity distribution matters.