Fitness & health, explained
Plain-English guides with the actual math and cited sources — no hype, no fluff. Each one pairs with a calculator so you can run your own numbers.
What Is a Healthy BMI? (And When BMI Misleads)
A healthy BMI sits between 18.5 and 24.9. Here are the full WHO/CDC ranges, the formula, and the cases where BMI gets it wrong.
Read guideHow to Calculate Your TDEE — and Actually Use It
Your TDEE is your BMR multiplied by an activity factor. Here's how to calculate it with Mifflin-St Jeor and turn it into real calorie targets.
Read guideHow Much Protein Do You Really Need Per Day?
The RDA is 0.8 g/kg, but active people building or keeping muscle need 1.6–2.2 g/kg. Here's how much protein you need and how to spread it out.
Read guideThe Navy Body Fat Method: How Accurate Is It?
The U.S. Navy body fat method estimates body fat from tape measurements within about 3-4% of DEXA. Here's how it works and where it fails.
Read guideHow to Estimate Your One-Rep Max Safely
Estimate your one-rep max from a lighter set using the Epley, Brzycki, or Lombardi formula, no maximal lift required. Here's how and how accurate it is.
Read guideMacros 101: How to Split Your Calories by Goal
Split your calories into macros by setting protein first by bodyweight, then fat, then carbs filling the rest. Here's the method and example splits by goal.
Read guideHow Big Should Your Calorie Deficit Be for Fat Loss?
A practical, evidence-based guide to sizing your calorie deficit for fat loss: 10-25% below TDEE, why aggressive cuts backfire, and protein's role.
Read guideHeart Rate Training Zones, Explained
What heart rate training zones mean, how to estimate max HR, the 5-zone model with a reference table, Karvonen reserve, and the 80/20 rule.
Read guideHow Much Water Should You Actually Drink?
The truth about hydration: why 8x8 is a myth, the National Academies adequate intake, bodyweight estimates, urine-color checks, and hyponatremia risk.
Read guide16:8 Intermittent Fasting: A Beginner's Guide
What 16:8 intermittent fasting actually is, how it compares to 18:6 and 5:2, what the evidence shows, who should avoid it, and practical tips.
Read guideSleep Cycles: Why Timing Your Wake-Up Matters
How the ~90-minute sleep cycle works, why waking between cycles feels easier, how to count back from your wake time, plus a go-to-bed table.
Read guideUnderstanding Your Fertile Window and Ovulation
How the menstrual cycle works, when ovulation really happens, the 6-day fertile window, and the signs that track it. Educational, not medical advice.
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