Blog
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.
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.
Single leg balance test: The 10-second test that predicts mortality
Failing the single leg balance test is associated with 84% higher adjusted mortality risk. Learn age benchmarks, caveats, and 8 exercises to improve balance.
Grip strength and mortality: a practical biomarker of healthy aging
Grip strength is linked with mortality, disability, sarcopenia, and biological aging. Learn the evidence, age norms, testing protocol, and exercises.
30-second chair stand test: safe setup, scores, and longevity
Learn the 30-second chair stand test setup, non-slip safety tips, age norms, and what sit-to-stand scores reveal about strength, fall risk, and longevity.
Critical power: The endurance metric that predicts aging better than VO2 max
Critical power marks your highest sustainable intensity. Learn how CP, W', durability, and VO2 max shape endurance, aging, and training decisions.
Running economy: Why efficiency matters more than speed for longevity
Running economy measures how efficiently your body uses energy at a given pace. Learn why this metric predicts aging better than speed, and how to improve it at any age.
Lactate threshold: The true fitness indicator that predicts how you age
Learn what lactate threshold is, how it declines with age, and 7 proven strategies to improve it. The fitness marker that predicts endurance, longevity, and biological aging.
Best time to exercise for longevity: What circadian science says
Best time to exercise for longevity, covering the 11 AM-5 PM window, chronotype, sleep, HRV, metabolism, circadian training, and evening workouts.