Training Stress Score (TSS) Guide: Track Workout Difficulty
Training Stress Score combines intensity and duration into a single metric. Learn what TSS means, how to track weekly totals, and use it to avoid overtraining.
Training Stress Score (TSS) is one of the most powerful metrics for understanding how hard your body actually worked — but Strava buries it deep in the settings. TSS combines intensity and duration into a single number: a 30-minute hard interval session might be 75 TSS, while an easy 2-hour run might be 45 TSS. Here's how to track it, why it matters, and how to use it to avoid burnout and plan smarter training.
Training Stress Score Essentials
- •TSS is effort + duration — A 10-minute hard interval workouts differently than 60 minutes easy
- •100 TSS ≈ one hour at threshold effort — Use this as a mental benchmark
- •Weekly totals reveal overtraining risk — 150 TSS/week is sustainable; 250+/week risks burnout
- •Garmin and power meters calculate TSS automatically — If you don't have data, estimated TSS is better than nothing
Training Stress Score Reference Table
Here's what different workouts typically score in TSS. Note that your specific number depends on your FTP (functional threshold power), fitness level, and the sport:
| Workout Type | Duration | Typical TSS | Recovery Time |
|---|---|---|---|
| Recovery Run | 30-45 min | 20-35 | None (active recovery) |
| Easy Run | 45-60 min | 35-50 | None (base building) |
| Long Run (Easy Pace) | 90-120 min | 80-120 | 1-2 days |
| Tempo Run | 40-50 min | 65-85 | 1 day |
| VO2 Max Intervals | 45-60 min | 80-110 | 2 days |
| Race (5K-10K) | 20-45 min | 90-140 | 2-3 days |
| Hard Cycling (Sustained Effort) | 60 min | 100-120 | 1-2 days |
📊 Note: TSS is sport-specific. Cycling power data gives precise TSS; running estimates are less accurate without a power meter. Strava estimates running TSS from pace, heart rate, and estimated FTP.
Weekly TSS: How Much Is Too Much?
Your weekly Training Stress Score is the best indicator of whether you're adapting or overtraining. Here's what different ranges mean:
✅ 100-150 TSS/Week (Sustainable Base Building)
This is the "sweet spot" for long-term fitness gains. You're getting enough volume to adapt without excessive fatigue. Recovery feels manageable, and you can handle consistent training for months. Good for building aerobic base or maintaining fitness during off-season.
⚡ 150-250 TSS/Week (Build or Peak Phase)
This is where race-specific training happens. You're adding intensity (threshold, VO2 max work) and volume to prepare for a goal race. Sustainable for 6-12 weeks, but requires solid recovery practices. After this phase, you need 1-2 weeks of reduced TSS to recover.
⚠️ 250+ TSS/Week (High Risk)
Elite athletes and well-trained athletes can handle this during peak training blocks, but it's unsustainable long-term. Above 300 TSS/week significantly increases injury and burnout risk. This is a competition phase, not a lifestyle. Recover aggressively.
How to See Your TSS on Strava
For Cyclists (Power Meter or Smart Trainer)
- 1. Sync your device: Make sure your power meter or trainer (Wahoo, TrainerRoad, etc.) is connected to Strava via Bluetooth or USB cable.
- 2. Check activity details: After uploading to Strava, open the activity and scroll to "Power." TSS appears in the Trainer Road data if you synced from TrainerRoad, or as "Normalized Power" and "Intensity Factor" if using Garmin or Zwift.
- 3. Use Garmin Connect: If you have a Garmin power-enabled device, Garmin Connect calculates TSS and syncs to Strava via the mobile app. Check Garmin Connect first, then verify it shows on the Strava activity.
For Runners (Garmin or Grit X)
- 1. Use a Garmin watch: Garmin watches calculate Training Stress Score automatically. Look for "Training Stress Score" in the Garmin Connect app after the run uploads.
- 2. Check Garmin Connect first: Garmin's own app shows TSS more reliably than Strava. Open Garmin Connect, find your run, and scroll to "Training Stress Score."
- 3. Sync to Strava: Garmin automatically syncs to Strava. The TSS metric may appear in Strava's expanded activity details or in the description if you use ActivityStat to auto-populate descriptions.
For Apple Watch / No Power Data
- 1. Use a TSS calculator: Search "Strava TSS calculator" or use tools like Training Peaks. Input your pace, heart rate, and duration; the calculator estimates TSS based on your FTP.
- 2. Manual entry: You can manually add TSS data in apps like Training Peaks, then sync back to Strava, though this is less common.
- 3. Estimated TSS: Strava estimates TSS from pace and heart rate if you set your FTP correctly in settings. Go to Settings → Fitness → Threshold to ensure your FTP is accurate.
How to Use TSS to Plan Smarter Training
1. Track Weekly Totals
At the end of each week, add up your TSS. If it's consistently above 250+, you're in a high-intensity block. Plan an easier week after 4-6 weeks to prevent burnout.
2. Balance Hard Days with Easy Days
High-TSS workouts (tempo, VO2 max) need recovery. If you did a 90 TSS workout today, tomorrow should be 30-40 TSS (easy run or rest). This pattern is called "polarized training."
3. Progressive Overload
Increase weekly TSS by 10% every 2-3 weeks during build phases. This gives your body time to adapt without shocking it. Don't jump from 120 to 200 TSS in one week.
4. Recognize Plateau Warning Signs
If your pace hasn't improved despite increasing TSS for 4+ weeks, you're likely overtraining or undereating. Drop TSS back 20-30% for a deload week to recover.
Track TSS Trends Automatically
ActivityStat pulls your TSS data (if available from your device) and tracks it over time on your activity dashboard. See your weekly totals, identify patterns, and adjust training accordingly:
Week 1: 145 TSS | Week 2: 165 TSS | Week 3: 180 TSS → Deload Week: 95 TSS
FAQ
Is TSS accurate for running?
Running TSS estimates are less accurate than cycling TSS (which uses power data). Strava estimates based on pace and heart rate. For the most accurate TSS, use a Garmin watch with metabolic stress calculations.
Why does my TSS seem low compared to how hard I felt?
If your FTP is set too high in Strava settings, TSS will underestimate. Go to Settings → Fitness → Threshold Power and double-check your FTP is accurate (usually 90% of your best 20-minute effort).
Is 250+ TSS per week dangerous?
Not if you're trained and recovering well, but it's the threshold where overtraining risk increases significantly. Monitor for signs: persistent fatigue, elevated resting heart rate, motivation loss, and illness frequency.
How does TSS compare to other metrics like TRIMP or Suffer Score?
TSS is cycling-specific and uses power data. TRIMP (TRaining IMPulse) is for runners using heart rate. Strava Suffer Score is proprietary and similar to TSS. All three measure training load; TSS is most scientific.
Should I use TSS to determine how much to race?
Absolutely. High-TSS races (especially marathons and half-marathons) need 2-3 weeks of recovery beforehand. If you race at 150 TSS, don't do another race until your weekly TSS is back to base levels.
Track Your Training Load. Avoid Burnout.
TSS is the most objective way to measure how hard your training is. Use weekly totals to balance intensity and recovery, and watch your fitness improve without hitting the wall.
Start Free Trial →Frequently Asked Questions
What does 100 TSS mean?
100 TSS ≈ one hour at threshold effort. Use this as a mental benchmark. A 30-minute hard interval workout might be 75 TSS; an easy 2-hour run might be 45 TSS.
How much TSS per week is too much?
100-150 TSS/week is sustainable base building. 150-250 TSS/week is fine for 6-12 weeks (race prep). 250+ TSS/week significantly increases injury and burnout risk.
Is TSS accurate for running?
Running TSS is estimated based on pace and heart rate. Less accurate than cycling power-based TSS, but still useful for tracking trends. For most accurate data, use a Garmin watch.
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