Race time predictors use the Riegel formula to project a marathon or half marathon time from a recent 5K. Here's the real math, why big jumps drift, and how fall marathon training season should read the number.
VO2 max has become the wearable world's favorite longevity metric. Here's how it's actually calculated, why your watch's estimate can be off by 10 points, and a real worked example.
Zone 2 training is everywhere right now, but most people doing it aren't actually in zone 2. Here's the real heart rate math, a worked example, and how to calculate your own zones.
Your pool pace per 100m almost never survives open water. Here's the real swim pace math, why open water runs slower, and how to set splits you can hit.
Your treadmill's 'Fat Burn' mode is misleading you. Learn how heart rate zones actually work, the Karvonen formula vs 220-minus-age, and how to train zones 1–5 for real results.
Most people pick their 16:8 fasting window by feel. Here's how to calculate your ideal eating window based on your sleep schedule, TDEE, and lifestyle — and why the difference matters.
Your one rep max unlocks every serious strength programme. Learn the Epley formula, how to estimate your 1RM safely, and how to use training percentages to actually build strength.
The '1 gram per pound' rule is everywhere — but the research says something different. Learn exactly how much protein you need based on your goal, weight, and activity level.
The problem isn't how long you sleep — it's when your alarm fires. Learn the 90-minute sleep cycle formula, how to calculate your perfect bedtime, and why timing changes everything.
Learn how pace, distance, and finish time connect, how to find your easy pace, and how to use heart rate zones and calorie data to run smarter — not just harder.