Precision calculators for endurance athletes who want answers fast.

Build a sweat-matched electrolyte drink for pennies, instead of paying $1.50 a stick.

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Build a Maurten-style maltodextrin + fructose race fuel for pennies. Exact gram recipe, osmolarity check, and gut-training plan.

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Find your per-hour sweat sodium loss and replacement target by event, sweat profile, and climate, with a pre-race loading plan.

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Run a naked-weight sweat test to find your exact hourly fluid loss, then pipe it straight into your sodium and drink-mix plans.

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Find your exact daily baseline and per-hour race-day fluid target from your body weight, sweat rate, and conditions. Urine color check and overdrinking warning included.

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Dial in your in-race carbohydrate target in grams per hour, the glucose to fructose split, and an hour-by-hour feed plan for running or cycling.

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Build a goal-matched endurance pre-workout from bulk ingredients. Exact doses, two-window timing, and a fraction of the cost of a commercial tub.

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A no-bloat, hour-by-hour carb-loading countdown that saturates glycogen without the heavy legs and gut bombs.

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Predict your marathon from a recent race, corrected for weekly mileage so low-volume runners get a realistic time instead of an optimistic Riegel guess.

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A personalized, zone-by-zone gear checklist so you never forget the timing chip again.

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Turn one FTP number into a complete cycling power-zone training structure.

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Find all 5 training heart-rate zones, with your Zone 2 aerobic base front and center.

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Plan a day-by-day taper from your training load and see whether you will actually peak on race day, no TrainingPeaks subscription needed.

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Enter a recent race result to get your VDOT running fitness score and five personalised training zone paces, built on Jack Daniels' proven system.

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Find which phase of your cycle race day falls in, then get phase-specific adjustments to temperature, sodium, fueling, and hydration strategy.

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Find your oxygen-corrected power and pace before you blow up chasing sea-level numbers at Leadville or UTMB.

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Stop panicking about summer paces. Convert your goal pace for real temperature and dew point so easy stays easy.

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Build a day-by-day heat-acclimation protocol that times your plasma-volume gains to land exactly on race day.

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Switching to shorter cranks? Get the exact saddle-height bump and gearing change so your fit and leverage stay dialed.

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Dial in front and rear tire pressure for road, gravel, tri, and MTB from your weight, tire and rim width, casing, and surface.

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Find your speed at any wattage, then see exactly how many minutes aero wheels or losing weight saves you over your race distance.

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See the watts and the minutes each aero upgrade actually buys you, for your position, speed, wind, and event, before you spend a cent.

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