Health Guides

Evidence-based articles on nutrition, fitness, sleep, and body composition — paired with free calculators so you can apply what you learn to your own numbers.

All Health Articles — 10 Guides

Nutrition & Body
What Is BMI and What Are Its Limitations?
BMI is a useful screening tool, not a diagnosis. What the number means, 6 evidence-based limitations, and better alternatives like waist-to-height ratio.
7 min read
Nutrition & Body
How to Calculate Your Macros for Any Goal
5-step framework: TDEE → calorie target → protein → fat → carbs. With a worked example for weight loss, muscle gain, and maintenance.
8 min read
Hydration
How Much Water Should I Drink Per Day?
The 8-glasses rule explained, the weight-based formula (0.5–1.0 oz/lb), and how activity, climate, and food affect your daily hydration needs.
7 min read
Nutrition & Weight
Intermittent Fasting Guide: Protocols, Benefits & How to Start
16:8, 5:2, OMAD, and Eat-Stop-Eat compared. The science on weight loss, muscle preservation, and who should avoid IF.
9 min read
Weight Loss
How to Lose Weight with a Calorie Deficit
How to calculate TDEE, set the right deficit size (300–500 kcal/day), and why protein and resistance training prevent muscle loss.
8 min read
Fitness & Performance
VO2 Max Explained: What It Is, Why It Matters, How to Improve It
VO2 max is a stronger mortality predictor than smoking or hypertension. Norms by age and sex, how to test it, and HIIT protocols to raise it.
8 min read
Fitness & Performance
Heart Rate Zones Guide: Training Smart at the Right Intensity
The 5 zones, what each does physiologically, and why the 80/20 rule (Zone 2 + HIIT) beats "gray zone" moderate training.
7 min read
Nutrition & Muscle
How Much Protein Do I Need Per Day?
The RDA prevents deficiency; active adults need 0.7–1.0g/lb. Targets by goal, best sources by leucine content, and protein timing guidance.
7 min read
Sleep & Recovery
Sleep Calculator Guide: How Much Sleep Do You Really Need?
Sleep cycles (90 min each), bedtime calculation tables, the real cost of chronic 6-hour nights, and evidence-based sleep hygiene tips.
7 min read
Nutrition & Weight
Keto Diet Macros: How to Calculate Them for Ketosis
Standard 70/20/5 ratio, step-by-step personalized macro calculation, SKD vs. TKD vs. CKD variants, and the keto adaptation timeline.
8 min read

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How to Use These Health Guides

Health decisions benefit from numbers, not just general advice. These articles are written to give you both the evidence and the calculation framework so you can apply the guidance to your specific situation. Each article explains the underlying science, provides worked examples with real numbers, and links to a calculator so you can run your own scenario without wading through textbook formulas.

The nutrition guides are built around the concept of energy balance — calories in versus calories out — with protein intake and activity level as the key levers. Understanding your TDEE (Total Daily Energy Expenditure) is the starting point for weight loss, muscle gain, or maintenance. The macro guide builds directly on TDEE to show how to split that calorie target across protein, fat, and carbohydrate in ratios appropriate for your goal.

The fitness articles cover VO2 max, heart rate zones, and running pace — metrics that matter far more to long-term health outcomes than most people realize. VO2 max is one of the strongest predictors of all-cause mortality, outperforming traditional risk factors like blood pressure or BMI in several large studies. The heart rate zones guide explains why most recreational exercisers train at the wrong intensity and how the 80/20 approach (Zone 2 plus HIIT) produces better results than constant moderate-intensity work.

All health content references published research and widely accepted clinical guidelines. None of this is medical advice — consult a licensed healthcare provider for diagnosis, treatment, or medical decisions. These articles are educational tools to help you understand your body and make more informed lifestyle choices.