FAQ
Frequently asked questions
What is Run TSS (rTSS)?
Run TSS quantifies the training stress of a run session using duration and intensity relative to your threshold pace. The formula is rTSS = Duration (hours) × IF² × 100, where IF is threshold pace divided by actual pace.
How is Run TSS different from Bike TSS?
The formula structure is the same, but run TSS uses pace instead of power. Bike TSS uses Normalized Power / FTP for intensity, while run TSS uses threshold pace / actual pace. Equal TSS numbers do not mean equal recovery cost — running carries more impact stress per point.
What is a good rTSS for a training session?
A typical age-group triathlete run session produces 30-80 rTSS. Sessions above 100 are hard key workouts. Long runs may reach 120-200 rTSS. Weekly totals of 200-400 across 3-5 sessions are common.
How do I find my threshold pace?
Threshold pace is roughly the fastest pace you could sustain for one hour. Use the VDOT Calculator with a recent race result, or use a 30-minute time trial and add 5-10 seconds per km to the average pace.
Evidence
References
- Running Training Stress Score (rTSS) Explained
TrainingPeaks
- Training Stress Scores (TSS) Explained
TrainingPeaks
- Load monitoring and training stress in endurance sport
PubMed Central
This calculator provides estimates based on published exercise science research. Individual responses vary. These outputs are not a substitute for coaching, medical clearance, or your own experience. Always listen to your body and consult a qualified professional before making significant changes to your training.
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