What is TSS and how can I use it? Follow

Training Stress Score (TSS)

Training places stress on your body, leading to positive adaptations when the right amount of stress and recovery are applied. If your workout generates too little stress, there will be no training adaptation. However, too much stress or insufficient recovery between rides can cause injury, illness, or prolonged recovery, negating your hard-earned progress.

TSS estimates the amount of stress placed on your body during a workout based on the intensity and duration of the exercise. For example, cycling at 100% FTP (Functional Threshold Power) for an hour equals a TSS of 100. Training for longer than an hour can result in a TSS greater than 100, even if the intensity is below FTP.

The formula used to calculate TSS for your ride is:

(# of seconds of the workout x Normalized Power x Intensity Factor) / (FTP x 3600) then x 100

TSS and your training

Now that you understand TSS, the big question is how to apply it to your classes. The answer depends on the class length and the variations in efforts above and below FTP.

For example, a rider performing a quasi-steady-state effort for an hour would have a TSS of 100. In contrast, a 60-minute steady-state class at 80% FTP would result in a TSS of 80.

By default, shorter rides will have a lower TSS. For instance, a 45-minute class at 100% FTP would have a TSS of 75, while the same class at 80% FTP would result in a TSS of 60.

However, these examples are unrealistic because indoor cycling classes typically last 45-60 minutes and include warm-up and cooldown periods. They also feature varying intensity intervals, including recovery.

Generally, a 60-minute indoor cycling class typically has a TSS of less than 85, while a 45-minute class usually falls below 65.

But not every ride should be that intense. The goal of training is to progressively increase intensity while overloading all systems to build strength over time.

Understanding TSS allows you to monitor this process more effectively and apply these principles to your training.

Our guidelines for 60-minute classes

Based on the information above, typical indoor cycling profiles, and our experience, we recommend the following TSS guidelines for 60-minute indoor cycling classes:

Base training: Aim for 55-65 TSS.

Medium to hard training: Aim for 65-70 TSS.

Hard training: Aim for 70-80 TSS.

Below are examples of workout profiles in these three categories

TSS 58 (note: 55-minute workout):

TSS 67 (note: 55-minute workout):

TSS 71 (note: 55-minute workout):

TSS 72

TSS 75

Considerations

Many riders tend to focus on a single ride, much like focusing on your diet for one day. Achieving your training goals in one session is great, but it's like dieting for a day and expecting long-term results—it’s the cumulative effort that counts.

While TSS is helpful for long-term training, here are some key considerations to keep in mind:

• Managing exercise volume can boost training efficiency and prevent overtraining. TSS is most valuable for determining the best combination of workouts and recovery over a 3-4 week mesocycle. Your daily TSS is less important unless it helps track accumulated stress over time.
  
  
• A high TSS doesn't equal high fitness. Subthreshold efforts over an hour can produce a higher TSS than a shorter, more intense ride.
  
  
• Comparing rides by TSS can be misleading. TSS doesn’t account for effort type, workout structure, or other physiological demands. For example, something as simple as a high cadence ride can increase the stress response if you ride outside your preferred cadence range.
  
  
• TSS only reflects stress from that specific activity. It doesn't account for other stressors like your job, sleep quality, biomechanical issues, inefficiencies, looming illness etc.
  
  
• Individual tolerance to training load varies. Your goal of achieving a higher TSS should fit within your overall training plan.