Endurance Tools
Explore our curated collection of calculators and guides related to Endurance. Use these scientific tools to optimize your performance and health.
Sweat Rate Calculator — Hydration Deficit & Fluid Needs
Calculate your personal sweat rate per hour, hydration deficit, and post-exercise fluid replacement target based on pre and post-exercise body weight.
Energy Availability Calculator — RED-S Risk Screening
Work out your energy availability in kcal per kg of fat-free mass and see whether you are fuelling enough to avoid Relative Energy Deficiency in Sport.
Ferritin Calculator — Iron Status Thresholds for Athletes
Read your ferritin result against the thresholds used for endurance athletes, which sit higher than standard reference ranges, with checks for inflammation and anaemia.
Menstrual Cycle Calculator for Athletes — Phase & Race Day Planner
Work out which cycle phase you are in today and which one your race falls in, with an honest read on what the training evidence does and does not support.
Gut Training Calculator — Build Carb Tolerance Before Race Day
Turn your current fuelling rate and your race target into a week-by-week progression, with the glucose and fructose split each step needs.
Heat Acclimation Calculator — Induction, Decay & Race Readiness
Track how far through a heat acclimation block you are, how much you have lost since your last heat session, and what will be left on race day.