Question 1

How much should I drink during a marathon?

Accepted Answer

Most runners need 400–800ml of fluid per hour, but individual sweat rate varies enormously — from 0.5L to 2.5L per hour depending on temperature, intensity, and body size. The only accurate approach is to calculate your personal sweat rate from pre/post weigh-ins and build your drinking plan from that number, not a generic formula.

Question 2

Why do I get cramps when running?

Accepted Answer

Running cramps are most often caused by a combination of dehydration, sodium depletion, and muscle fatigue — not just one factor. Drinking large amounts of plain water without replacing electrolytes can actually make cramping worse. The fix is to start well-hydrated, replace sodium during long efforts, and match your fluid intake to your actual sweat rate.

Question 3

How many gels do I need for a marathon?

Accepted Answer

Plan for one gel (20–25g of carbohydrate) every 30–45 minutes from around mile 4 onwards — roughly 5–7 gels total. The right number depends on your finish time, body weight, and gut tolerance at race pace. Faster runners with trained guts can push toward 60–90g of carbs per hour; slower runners may take in less per hour but need more gels overall.

Question 4

When should I take my first gel in a race?

Accepted Answer

30–45 minutes in — before you feel tired or hungry. By the time you feel depleted, glycogen is already running low and mid-race recovery is much harder than maintaining fuel levels from the start. Practise gel timing on long training runs so your gut is ready on race day.

Question 5

How do I calculate my sweat rate?

Accepted Answer

Weigh yourself in kg immediately before and after a 60-minute effort without drinking. Every 1kg of body weight lost equals approximately 1 litre of sweat. Your sweat rate changes with temperature, intensity, and fitness level — it's worth testing across different conditions. Sweatr automates this calculation from your pre/post weigh-ins each session.

Question 6

Are Garmin calorie estimates accurate enough for fueling?

Accepted Answer

Directionally useful, but often off by 10–20% or more depending on GPS conditions, heart rate variability, and individual metabolism. Don't build a precise fueling plan from the number alone. Use it as a rough baseline and calibrate against how you actually feel and perform across multiple sessions.

Question 7

What should I eat the morning of a race?

Accepted Answer

A carbohydrate-heavy meal 2–3 hours before your start — oats, white toast, or rice work well for most athletes. Keep fat and fibre low to minimise GI risk. Add a small carb top-up (a banana or gel) 30–45 minutes before the start if your stomach tolerates it. Practise this routine on long training runs — race morning is not the time to try something new.

Question 8

What does HRV mean for runners?

Accepted Answer

Heart rate variability (HRV) measures the variation in time between heartbeats. Higher HRV generally signals good recovery; lower HRV indicates stress, fatigue, or under-recovery. Garmin and Apple Watch both track it nightly. Weekly trends matter far more than single readings — always compare against your own personal baseline, not a published target number.

Question 9

What wearables does Sweatr support?

Accepted Answer

Sweatr connects to Apple Watch and Strava. Your workout data syncs automatically — Sweatr uses it to personalise your hydration and fuelling plan based on your actual training load and history, not population averages.

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