FUEL WELL. TRAIN SUSTAINABLY.

Know what remains.

Estimate your energy availability after training and explore what a well-fueled day might look like.

EA = (intake − net exercise expenditure) ÷ fat-free mass
Understand the number. Explore a fuel plan. Support consistent training.

01 / CALCULATE

Your energy, at a glance.

All values describe the same 24-hour period.

Enter your details

Body weight kgBody fat % Enter fat-free mass directly insteadTotal energy intake kcal/day, including exercise fuelExercise energy expenditure kcal/day

My device reports gross exercise calories

Use exercise expenditure above resting expenditure, not all-day calories. If you tick gross, enter exercise duration below to approximate resting energy during exercise.

EA reference to explore kcal/kg FFM/day

45Research reference, not a personal prescription

Enter valid, nonnegative values and a positive fat-free mass.

ESTIMATED ENERGY AVAILABILITY

—

kcal / kg fat-free mass / day

0304560+

Enter your details to see your energy availability.

Fat-free mass—

Net exercise expenditure—

Energy after exercise—

Intake at selected EA reference—

162 kcal above entered intake.

This is an estimate, not a diagnosis of LEA or RED-S. Higher EA does not rule out RED-S.

02 / PUT IT ON YOUR PLATE

Fuel your day.

Build your day

Plan energy from

Training sessions

Sessions shape meal timing and training fuel. Their durations do not estimate exercise expenditure; enter combined net exercise calories above.

Illustrative meal plan

Daily energy used for plan—

Session carbohydrates—

Estimated meals & snacks—

Example food combinations and calories are approximate. Portion sizes are illustrative, not a tailored dietary prescription. During-session fuel is counted inside your daily total, not added on top. Avoid treating a single-day calculation as a clinical target.

03 / UNDERSTAND THE NUMBER

Understand the science.

What does EA measure?

EA is dietary energy left after exercise, divided by fat-free mass. It differs from energy balance: everyday movement and resting metabolism aren't subtracted from this formula.

Low EA and RED-S

Prolonged or severe low energy availability can contribute to Relative Energy Deficiency in Sport (RED-S), affecting recovery, bone health, immunity and other body systems. Evaluation considers symptoms and health history—not this number alone.

References, not verdicts

Values near 30 and 45 kcal/kg FFM/day largely originate from research in women. Reliable cutoffs, especially for men, aren't established. Neither number diagnoses or excludes RED-S.

Further reading: 2023 IOC REDs consensus statement · Carbohydrate intake during exercise — Jeukendrup (2014).