📝 Blog

What TDEE actually means, how it's calculated, and why most online calculators overestimate your real daily calorie burn — plus how to calibrate it.

Full resting heart rate chart by age and fitness level, what raises or lowers it, and when a high or low number is actually worth worrying about.

BMI has well-documented flaws — it ignores muscle, fat distribution, and body type. Here's what the research says, and better alternatives to track.

Evidence-ranked interventions for lowering biological age — exercise, body composition, sleep, smoking, and stress — with realistic timelines for each.

Find out what a good VO₂max is for your age and sex. Complete ACSM norms tables, health risk categories, and how to improve your cardio fitness.

Research shows Mifflin-St Jeor is more accurate than Harris-Benedict. Here's what the science says and which formula your calculator should use.

Biological age vs chronological age: what it is, why it matters, and 4 ways to measure it — from free biomarker calculators to epigenetic DNA tests.

Four practical methods to estimate your VO₂max without a lab test: Uth formula, Cooper run, Rockport walk, and fitness trackers. Includes age norms.