Fitness Fatigue Balance
Update caller-calibrated fitness and fatigue states from a daily training load.
Description
A fitness–fatigue update retains part of each prior state and adds a load-scaled contribution.
A fitness–fatigue update retains part of each prior state and adds a load-scaled contribution. The state coefficients are supplied calibration parameters.1
Update caller-calibrated fitness and fatigue states from a daily training load.
When to use Fitness Fatigue Balance
Use this tool to update caller-calibrated fitness and fatigue states from a daily training load.
Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
How to use Fitness Fatigue Balance and understand its results
- Prepare the measured movement, timing, load or preassigned score requested. Keep protocols, units, paired measurements and caller-selected thresholds consistent.
- Enter previousFitness, previousFatigue, todayTrainingLoad, fitnessRetention, fatigueRetention, fitnessLoadGain, fatigueLoadGain using the field table and calculation rules, then run the tool.
- Read fitness, fatigue, trainingStressBalance. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| previousFitness | Previous fitness | number | Required |
| previousFatigue | Previous fatigue | number | Required |
| todayTrainingLoad | Today training load | number | Required |
| fitnessRetention | Fitness retention | number | Required |
| fatigueRetention | Fatigue retention | number | Required |
| fitnessLoadGain | Fitness load gain | number | Required |
| fatigueLoadGain | Fatigue load gain | number | Required |
Enter nonnegative states/load/gains and retention factors 0–1. Return both new states and signed balance.
fitness=priorFitness×retention+load×gain; fatigue similarly; balance=fitness−fatigue Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| fitness | Fitness | number |
| fatigue | Fatigue | number |
| trainingStressBalance | Training stress balance | number |
{
"input": {
"previousFitness": 100,
"previousFatigue": 80,
"todayTrainingLoad": 20,
"fitnessRetention": 0.95,
"fatigueRetention": 0.8,
"fitnessLoadGain": 0.1,
"fatigueLoadGain": 0.2
},
"output": {
"fitness": 97,
"fatigue": 68,
"trainingStressBalance": 29
}
}Limitations and assumptions
No coefficient fitting, multiday history or objective readiness prediction is performed.
Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Session RPE Training Load: Calculate session-RPE training load in arbitrary units. For a complementary task, use HRV Rolling Baseline: Compare current HRV with the prior seven-day mean and caller tolerance.
References
-
Fitness Fatigue Balance — tool.io
Similar or alternative tools
- Session RPE Training Load
Calculate session-RPE training load in arbitrary units.
- HRV Rolling Baseline
Compare current HRV with the prior seven-day mean and caller tolerance.