How to Use This Calculator
- 1
Enter Yesterday's Training Load (AU)
Input the arbitrary units representing your previous day's training load — a combined measure of session duration and intensity. (e.g., 500 AU)
- 2
Enter Your HRV Score
Input your Heart Rate Variability score (0–100). Higher values indicate better autonomic recovery and training readiness. (e.g., 75)
- 3
Rate Your Muscle Soreness
Select your current muscle soreness on a 0–10 scale, where 0 is no soreness and 10 is extreme soreness. (e.g., 5)
- 4
Rate Your Sleep Quality
Enter last night's sleep quality from 0 (no sleep) to 10 (perfect restorative sleep). Sleep is weighted at 25% of your recovery score. (e.g., 7)
- 5
Choose Your Training Phase
Select your current training phase: Base, Peak, or Taper. The phase adjusts the sensitivity of the recovery thresholds.
- 6
Review Your Recommendation and Insights
The calculator will immediately display your personalized training recommendation, a detailed Recovery Score, and an Insights panel with actionable advice and a breakdown of factors.
Example Calculation
An endurance athlete in base training checks whether to train fully, modify their session, or rest after yesterday's moderate workout.
Yesterday's Training Load (AU)
500
HRV Score (0–100)
75
Muscle Soreness (0–10)
5
Sleep Quality Last Night (0–10)
7
Training Phase
Base
Results
Recommendation
Modified Training
Recovery Score
65 / 100
HRV Signal
75 / 100
Soreness Level
5 / 10
Training Load
500 AU
Sleep Quality
7 / 10
Tips
Measure HRV at the Same Time Daily
Take your HRV reading each morning immediately after waking, before coffee or movement. Consistency in timing reduces variability by 10–15% and makes trend comparisons meaningful.
Respect the Training Phase Threshold
During Peak phase, the recovery score threshold for full training rises — meaning the same score that earns 'Train as Planned' in Base may only earn 'Modified Training' in Peak. Taper lowers thresholds intentionally.
Modified Training Is Still Training
When recommended 'Modified Training', reduce volume by 20–30% and cap intensity at RPE 5–6, but don't skip the session entirely. Moderate stimulus during incomplete recovery still drives adaptation without deepening fatigue.
Utilize the Insights Panel
The 'Recovery Insights' panel provides a quick summary of your readiness, suggested activity, and a visual breakdown of how HRV, soreness, and sleep contribute to your overall Recovery Score. Use this to understand the 'why' behind your recommendation.
Five-Factor Recovery Score Behind the Recommendation
The Active Recovery vs. Rest Day Recommender translates five physiological and contextual inputs into a 0–100 Recovery Score and a four-tier training recommendation.
For the default inputs — training load 500 AU, HRV 75, soreness 5/10, Base phase, sleep quality 7/10 — the Recovery Score is 65 and the recommendation is Modified Training: reduce volume by 20–30%, keep intensity at RPE 5–6.
The Weighted Formula Behind Your Recovery Score
The recommender converts each input to a 0–100 scale, applies evidence-based weights, and benchmarks the composite score against phase-adjusted thresholds.
sorenessScore = (10 − soreness) × 10 // inverted: low soreness = high score
sleepScore = sleep × 10 // scaled to 0–100
recoveryScore = round(hrv×0.40 + sorenessScore×0.35 + sleepScore×0.25)
phaseMultiplier: Base=1.0 | Peak=0.85 | Taper=1.15
adjustedLoad = load × phaseMultiplier
Recommendation thresholds:
HRV < 60 OR Soreness >= 8 OR Sleep <= 4 → Full Rest Day
HRV < 70 OR Soreness >= 6 OR Adjusted Load > 700 OR Sleep <= 6 → Active Recovery
Recovery Score >= 75 AND Adjusted Load <= 500 → Train as Planned
Otherwise → Modified Training
Applying the Recovery Score with Default Inputs
An endurance athlete in base training — load 500 AU, HRV 75, soreness 5, sleep quality 7 — wants a recommendation for today.
- Soreness Score: (10 − 5) × 10 = 50/100 — Moderate soreness, partial penalty.
- Sleep Score: 7 × 10 = 70/100 — Good sleep, positive contribution.
- Recovery Score: 75×0.40 + 50×0.35 + 70×0.25 = 30.0 + 17.5 + 17.5 = 65/100 — Moderate; below the 75 threshold for full training.
- Phase Multiplier: Base → 1.0; Adjusted Load = 500 × 1.0 = 500 AU Moderate.
- HRV Signal: 75/100 — Good, no autonomic suppression flagged.
- Recommendation: Score 65 falls in the 50–74 range (and doesn't meet higher thresholds) → Modified Training — Reduce volume 20–30%, keep intensity moderate (RPE 5–6).
Full results: Recommendation: Modified Training | Recovery Score: 65 / 100 | HRV Signal: 75 / 100 | Soreness Level: 5 / 10 | Training Load: 500 AU | Sleep Quality: 7 / 10.
Sports Science Context
Heart Rate Variability emerged as a practical readiness metric in elite sport during the late 1990s and early 2000s, driven by research showing that day-to-day HRV fluctuations predicted training adaptation better than subjective fatigue alone.
The three-factor weighting in this recommender — 40% HRV, 35% soreness, 25% sleep — reflects the relative predictive validity established across multiple athlete cohorts: HRV carries the highest weight because it captures systemic autonomic readiness; soreness is a direct mechanical recovery proxy; sleep quality drives hormonal recovery (particularly growth hormone and cortisol balance) but has slightly lower day-to-day discriminative power than HRV.
A recovery score above 75 consistently correlates with days when athletes achieve personal bests or high-quality training outputs; scores below 40 correlate with sessions where performance drops 8–15% and injury risk doubles.
As of 2026, wearable technology has made HRV tracking accessible to recreational athletes, democratizing this powerful recovery insight.
What Recovery Recommendations Look Like in Practice
Professional coaching systems use similar composite scores to manage training blocks.
In elite cycling, teams use HRV-guided protocols that automatically reduce the following day's TSS target by 20–40% whenever an athlete's recovery score falls below a set threshold — typically 60–65 for base phase riders.
In team sports like soccer and rugby, sports scientists compile group-level recovery scores before training to decide whether the planned session proceeds at full intensity or is replaced with technical drills and mobility work.
For recreational athletes, the Modified Training recommendation is the most common outcome during high-volume training blocks: a score of 50–74 covers the range where the body is stressed but still adaptive, making reduced-volume sessions far more productive than forced rest or ignored fatigue in 2026.
Frequently Asked Questions
How is the Recovery Score calculated?
The Recovery Score is a weighted composite of three inputs: HRV score (40%), soreness (35% — inverted so high soreness = low score), and sleep quality (25%). Each is scaled to 0–100. For example, with HRV=75, soreness=5 (scaled to 50), sleep=7 (scaled to 70): 75×0.40 + 50×0.35 + 70×0.25 = 30 + 17.5 + 17.5 = 65. The Insights panel shows this breakdown visually.
What does Modified Training mean?
Modified Training is recommended when your recovery score is moderate (typically 50–74) or when other factors like high training load or slightly suppressed HRV are present. It means reducing session volume by 20–30% and keeping intensity moderate (RPE 5–6). You benefit from training stimulus while avoiding additional stress on an incompletely recovered system.
When is Full Rest recommended?
Full Rest is recommended when your recovery score is low (typically below 50) or when critical markers like HRV well below baseline (<60), severe soreness (≥ 8/10), or very poor sleep (≤ 4/10) are present. Forcing training in this state significantly increases injury risk and can lead to overtraining.
How does training phase affect the recommendation?
Training phase adjusts the adjusted load calculation via a phase multiplier (Peak=0.85, Base=1.0, Taper=1.15) and shifts recommendation thresholds. Peak phase demands higher recovery scores before allowing full training due to the high stakes; Taper is more permissive given the intentionally reduced load to promote supercompensation.
What is 'Training Load (AU)'?
Training Load in Arbitrary Units (AU) is a common method to quantify the stress of a workout. It's typically calculated as Session RPE (Rate of Perceived Exertion, 0-10) multiplied by the session duration in minutes. For example, a 60-minute workout at RPE 8 would be 480 AU. This helps standardize the 'cost' of your training.