Docs/Methodology

How your targets are calculated: Our nutrition engine

We do not use a one-size-fits-all formula. Every target you see is calculated fresh each day based on who you are, how hard you trained, and what kind of session it was. This page explains exactly how that works.

Your baseline: BMR and activity level

Everything starts with your Basal Metabolic Rate, the number of calories your body burns just to keep you alive. We calculate this using the Mifflin-St Jeor equation, which is the most validated formula for active adults and takes your weight, height, age, and sex into account.

That baseline is then multiplied by a Physical Activity Level (PAL) factor based on how active you are outside of your training. A desk worker doing one training session a day has a different energy need to someone who is on their feet all day before even getting on the bike. You set this during onboarding and can update it any time in your profile.

The result of BMR x PAL is your Total Daily Energy Expenditure (TDEE). That is the foundation everything else is built on.

Training load adjustment

On days when you have a training session, your calorie target goes up. How much it goes up depends on how hard the session is.

  • Light (under 200 kcal burned): +350 kcal

  • Moderate (200-500 kcal): +600 kcal

  • Hard (500-900 kcal): +1,000 kcal

  • Very Hard (900-1,400 kcal): +1,500 kcal

  • Race (over 1,400 kcal): +2,200 kcal

If you have planned a session in advance, the app uses that session's estimated calorie burn to set the load category before you even start. Once you complete the session and it syncs from your device, the load is recalculated based on what actually happened.

For cycling sessions where you have a power meter, we use the actual kilojoule output to calculate calorie burn rather than a flat-rate estimate.

How your macro split is set

Once we know your calorie target for the day, we work out how those calories should be split between protein, carbohydrate, and fat. This is not fixed. It shifts based on three things: how hard you trained, what kind of sport it was, and your biological sex.

Training intensity and carbohydrate demand

The harder the endurance session, the more carbohydrate-forward your split becomes. On a rest day, carbs sit around 40%. On a race day, they can climb to 65%. This reflects the well-established physiology that glycogen is the primary fuel at high intensities, and needs to be both available during the effort and replaced afterwards.

Sport type: endurance, strength, and mixed

Endurance sports (cycling, running, swimming, rowing, triathlon) use the carbohydrate-forward approach above.

Strength and resistance training (gym sessions, weight training, crossfit, HIIT) flips the balance. The primary adaptation signal is muscle protein synthesis, not glycogen replenishment. On a hard gym day, protein sits around 30-35% of calories rather than the 20% you would see on a hard bike ride. Supported by research from Phillips and Van Loon (2011) and the ISSN position stand on protein and exercise.

Mixed and intermittent sports (tennis, padel, team sports, skiing) sit between the two. The split lands around 27% protein and 47-50% carbohydrate on a moderate to hard day, in line with IOC consensus guidelines for intermittent sport athletes.

Female athlete adjustments

Research by Tarnopolsky et al. and Horton et al. has consistently shown that females oxidise significantly less glycogen and significantly more fat than males at the same relative submaximal intensity. Oestrogen promotes lipid oxidation and glycogen sparing at submaximal workloads. The fat percentage in the split has a higher floor for female athletes, particularly at rest and lower intensities. At race-level intensities the difference narrows considerably.

Menstrual cycle adjustments

If you are using cycle tracking, your calorie target shifts slightly based on where you are in your cycle. The luteal phase raises resting metabolic rate by roughly 100-150 kcal per day due to elevated progesterone. Cadence Fuel adds a small upward adjustment during this window to reflect that real increase.

On-bike fuelling

Calories consumed during a ride are tracked separately from your daily meal budget. The macro split for on-bike fuelling is deliberately carbohydrate-forward at around 85% carbs. During sustained exercise, fat and protein slow gastric emptying and can cause GI distress. The target is exogenous carbohydrate oxidation at 60-90 grams per hour for efforts over 75 minutes.

Rest days

On a rest day your calorie target is simply your TDEE, with no training load adjustment. The macro split shifts to roughly 30% protein, 40% carbs, and 30% fat. Rest days are when muscle repair happens, so protein stays elevated.

Hydration targets

Your daily water target is calculated from body weight (35 ml per kg as a base) with an additional allowance on training days based on load. These figures align with ACSM fluid replacement guidelines. If you have done a sweat test in Cadence Fuel, those results are used to personalise your in-ride hydration recommendations further.

A note on estimates

All of this is based on well-established population-level science, but your body is not average. Targets are a starting point. If you are consistently hungry on rest days, your TDEE estimate might be low. Use the numbers as a guide, track how you respond, and adjust from there.

The goal of Cadence Fuel is not to make you track obsessively. It is to give you accurate, sport-specific numbers so that when you do pay attention to your nutrition, you are working with information that actually reflects your life as an athlete.