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RiverMath

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Body and training

Composition, calories, pace, heart rate, sleep and a pregnancy due date.

BMI

Body mass index from weight and height, using the WHO bands for adults.

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Body fat

The US Navy circumference method. A tape-measure estimate, not a DEXA scan.

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Calories

Basal metabolic rate from Mifflin–St Jeor, then a TDEE estimate from activity.

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Ideal weight

Devine ideal body weight from sex and height. A reference, not a goal you must hit.

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Daily water

A litres-per-day estimate from body weight and activity minutes.

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Macros

Split a daily calorie target into grams of protein, carbohydrate and fat.

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Waist-to-hip ratio

Waist divided by hip, a tape measure, not a DEXA scan.

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Weight change

Weeks to a target weight from a daily surplus or deficit, at 7700 kcal per kilogram.

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Steps to distance

Kilometres and a calorie sketch from steps, height and weight.

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Running pace

From distance and finish time: pace per kilometre and average speed.

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Race predictor

An estimate for 5 km, 10 km, the half marathon and the marathon from a distance you have already raced.

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One-rep max

Estimate a one-rep max from a set you already lifted, using Epley.

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Heart-rate zones

Karvonen zones from age and resting heart rate. Max HR is 220 minus age.

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VO2 max (Cooper)

A VO2 max sketch from the metres you cover in twelve minutes.

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Sleep cycles

A wake time or bedtime from 90-minute cycles plus the minutes you need to fall asleep.

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Sleep debt

Hours short of the sleep you wanted, over a run of nights.

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Caffeine left

How much of a dose is still in you after a number of hours.

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Fasting window

Hours fasted and the eating window from two clock hours.

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FFMI

Lean mass from body-fat percent, then FFMI from height.

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Protein target

Daily protein from kilograms and grams per kilogram.

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Max heart rate

Two textbook HRmax sketches from age.

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Body surface area

Mosteller surface area from height and weight.

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Ovulation window

A fertile window and a due-date sketch from the last period and cycle length.

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Pregnancy

Due date, gestational age and a fertile window from the last period and cycle length.

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