Training Status: How Your Fatigue Level Determines Progress or Overload
You’re training diligently – but do you know how much strain your body is currently under? That’s exactly where the fatigue level comes into play. It helps you identify whether you’re training optimally, overreaching, or perhaps even doing too little.
What Is the Fatigue Level?
The fatigue level describes the ratio between your short-term training load (Acute Training Load or ATL) and your long-term training load (Chronic Training Load or CTL). Simply put, it shows how much your current training stresses your body compared to your usual training baseline.
It’s calculated by dividing ATL by CTL.
A value of 1.0 means you’re currently training at the same level as your average over the past weeks. If the value is above or below that, it tells you a lot about your current training status.
What Do the Values Mean?
Your fatigue level, expressed as a value between 0 and 2, reflects your body’s current load status. The optimal range – the so-called “sweet spot” – lies between 0.8 and 1.3.
Fig. 1.: Chronic & acute Workload Ratio (Windt & Gabbett, 2017)
⬇️ Detraining (<0.8)
If your fatigue level is below 0.8, your body is in a very well-rested state. This means you’ve done significantly less training compared to previous weeks. Your fitness decreases during this time, but your form may increase slightly. This could happen during tapering, the off-season, or an extended illness. Learn more about the effects of longer training breaks in the blog article on detraining.
🛌 Recovery (0.8 – 1.0)
If your fatigue level is between 0.8 and 1.0, it indicates a light recovery phase. These phases are crucial because fitness cannot be increased continuously. Your body needs these breaks to rest and adapt to training stimuli. In the figure, this recovery is represented by the blue line.
✅ Productive (1.0 – 1.3)
With a fatigue level between 1.0 and 1.3, you’re maintaining or even improving your current fitness level. Your body is being challenged, but it’s in the ideal range to increase performance.
⚠️ Overreaching (1.3 – 1.5)
If your fatigue level lies between 1.3 and 1.5, it means you’re currently training a bit too much. In Figure 3, this is marked with the yellow line. This can happen if a session turns out longer or harder than planned. You shouldn’t stay in this “overreaching” zone for too long, as it increases the risk of overload or injury.
⚠️ Overtraining (1.5 or higher)
If your value is above 1.5, a rest day is essential. In this case, you’ve trained too much recently, and your body wasn’t adequately prepared for that load. Two scenarios could lead to this:
You’ve only recently started training and don’t yet have a consistent training history. This means Enduco doesn’t know you well enough yet. It takes about three weeks for Enduco to properly assess your training load and give you a realistic fatigue score. In the meantime, just make sure you don’t ramp up your volume too quickly.
You’ve just completed a long and intense race. In this case, the value may spike to around 1.5. However, Enduco specifically prepares you to handle race efforts well.
Fig. 3: Fatigue level over 3 months in the analysis tab.
Why Is the Fatigue Level So Important?
Your fatigue level is a key indicator for preventing injuries, managing progress effectively, and avoiding overtraining. Ambitious athletes often push themselves too hard. The fatigue level gives you a clear signal of when your body needs rest – or when it’s ready to push harder.
Conclusion
The fatigue level is your personal compass for training. It tells you when to push – and when less is more. That way, you train not just harder, but above all, smarter.
Sources:
Williams, S., West, S., Cross, M. J., & Stokes, K. A. (2017). Better way to determine the acute: chronic workload ratio? British Journal of Sports Medicine, 51(3), 209–210.
Windt, J., & Gabbett, T. J. (2017). How do training and competition workloads relate to injury? The workload—injury aetiology model. British Journal of Sports Medicine, 51(5), 428–435.