Training Stress Score (TSS) Calculator
Informational calculator for rowing logs: estimate TSS and Intensity Factor, compare sessions, and plan weekly load.
Workout Data
FTP (Functional Threshold Power)
2k to FTP uses a fixed estimate factor (0.88). Use it as a planning baseline and refine with ongoing logs.
Enter Workout Data
Enter duration or distance plus watts or split, then add FTP to calculate Training Stress Score for your training log.
Rowing TSS Calculator: The Complete Guide to Training Stress Score
Use TSS as a session-load estimate for erg logs. Compare workouts, review consistency over time, and support planning decisions.
How to Calculate Training Stress Score (TSS) on a Concept2 Erg
Training Stress Score (TSS) is a workload estimate based on workout duration and intensity relative to your Functional Threshold Power (FTP). Originally created for cycling, TSS has been adapted for rowing and ergometer training, sometimes called "rTSS" or rowing TSS.
A TSS of 100 represents the stress of a one-hour workout at your FTP—essentially, your maximum sustainable effort for 60 minutes on the Concept2 or other rowing ergometer. By tracking ergometer stress score, you can consistently compare session load and plan recovery windows.
For rowers, TSS is particularly valuable because it accounts for both the duration of your erg sessions and the intensity at which you're working, giving you a single number to compare vastly different workouts— whether it's a 90-minute steady-state row or a brutal 8×500m interval session.
Note: TSS is a workload estimate, while calories represent energy-use estimates. This page uses a Concept2-style calories-per-hour estimate scaled by workout duration.
How TSS is Calculated
TSS Formula:
TSS = (Duration × NP × IF) ÷ (FTP × 3600) × 100
Where: Duration is in seconds, NP = Normalized Power, IF = Intensity Factor, FTP = Functional Threshold Power
Intensity Factor (IF):
IF = NP ÷ FTP
IF of 1.0 means you're at threshold. IF > 1.0 means above threshold.
Normalized Power (NP):
NP = ⁴√(avg of 30s rolling avg⁴)
For steady-state rowing, NP ≈ Average Power. For intervals, NP > Avg Power.
Example Calculation:
60-minute steady-state row at 200W with FTP of 220W:
- • NP = 200W (steady-state, so NP ≈ Avg Power)
- • IF = 200 ÷ 220 = 0.91
- • TSS = (3600 × 200 × 0.91) ÷ (220 × 3600) × 100 = 83
Result: A 60-minute row at 91% of FTP produces a TSS of 83—a moderate training load.
Understanding Intensity Factor (IF)
Intensity Factor (IF) tells you how hard a workout was relative to your threshold. It's the ratio of your Normalized Power to your FTP. Here's what different IF values mean:
TSS Guidelines & Recovery
Single Workout TSS
Weekly TSS Targets
Performance Management: CTL, ATL, and TSB
TSS is the foundation for the Performance Management Chart (PMC), which tracks three key metrics over time to help you balance training load with recovery:
CTL (Fitness)
Chronic Training Load
42-day exponentially weighted average of daily TSS. Represents your "fitness" or training base.
ATL (Fatigue)
Acute Training Load
7-day exponentially weighted average of daily TSS. Represents your recent "fatigue" level.
TSB (Form)
Training Stress Balance
CTL − ATL. Positive values often align with fresher days, while negative values usually reflect accumulated load.
Frequently Asked Questions
What is a good TSS for a rowing workout?
It depends on your goals and training phase. For a typical training session, 50-150 TSS is common. Easy recovery rows might be 30-50 TSS, while hard interval sessions can reach 100-150+ TSS. A 2000m race effort typically generates 40-60 TSS despite being short.
How do I find my FTP for rowing?
The most common methods are: (1) 20-minute test: Row as hard as you can for 20 minutes, then multiply average power by 0.95. (2) 2000m test: Use your 2k average power multiplied by 0.88. (3) Use our FTP-Row Estimator tool for guided testing protocols.
Calculate your FTP →Should I use Normalized Power or Average Power?
For steady-state rows, Average Power is fine (NP ≈ Avg Power). For interval workouts with significant power variation, use Normalized Power to better capture the metabolic cost. NP is typically 5-15% higher than Average Power for intervals and better reflects the true metabolic demand.
How much weekly TSS should I accumulate?
This varies by athlete and training phase. Recreational rowers might accumulate 300-400 weekly TSS, while competitive athletes often reach 600-800+. Build gradually (no more than 10% increase per week) and include recovery weeks every 3-4 weeks.
Can TSS be used for on-water rowing?
Yes, but you need power data from a SpeedCoach or similar device. Without power, you can estimate TSS using heart rate-based methods (hrTSS), though this is less accurate than power-based TSS.
Related Rowing Tools
FTP-Row Estimator
Calculate your Functional Threshold Power
Heart Rate Zones
Calculate HR-based training zones
VO₂max Estimator
Estimate your aerobic capacity
Power Curve Builder
Build your power-duration profile
Critical Power Calculator
Determine CP and W' values
Rowing Performance
Comprehensive performance analysis
Scientific References
• Concept2 pace-power conversion reference:Concept2 Watts Calculator
• Concept2 calorie and MET formula notes:Concept2 Help Center
• Coggan and Allen framework overview:TrainingPeaks TSS guide
• Rowing power relevance context:Egan-Shuttler et al. (PubMed)
• 2000m determinants context:Ingham et al. (PubMed)
Understanding TSS
TSS = (Duration in seconds × Normalized Power × IF) / (FTP × 3600) × 100. A one-hour all-out effort at FTP equals exactly 100 TSS. Guidelines: under 150 TSS/day is manageable for most rowers; 150-300 requires planned recovery; above 300 is race-day territory. Weekly TSS between 300-700 is typical for well-trained club rowers.
Formula details: Methodology.
Related Tools
- FTP Calculator — you need FTP to calculate TSS
- Heart Rate Zones — use alongside TSS for dual monitoring
- Session Comparator — compare TSS across workouts
Standards & Guides
- Training Zones Explained — full guide to zone-based rowing
- How to Improve Your 2K Time — manage TSS through a training block
- 5000m Rowing Standards — endurance benchmarks by age and ability