What is a High Fatigue Score on Training Peaks and Why Does It Feel Like Running a Marathon in Your Sleep?

What is a High Fatigue Score on Training Peaks and Why Does It Feel Like Running a Marathon in Your Sleep?

Training Peaks is a powerful tool for athletes and fitness enthusiasts to track their performance, plan workouts, and analyze data. One of the key metrics it provides is the Fatigue Score, also known as Acute Training Load (ATL). But what exactly does a high fatigue score mean, and why does it sometimes feel like you’re running a marathon in your sleep? Let’s dive into the details.


Understanding Fatigue Score on Training Peaks

The Fatigue Score on Training Peaks is a numerical representation of the short-term stress your body is under due to recent training. It’s calculated using your Training Stress Score (TSS), which measures the intensity and duration of your workouts. A high fatigue score indicates that your body is experiencing significant stress, which can be both a sign of progress and a warning signal.

How Fatigue Score is Calculated

  • Training Stress Score (TSS): Every workout is assigned a TSS based on its intensity and duration. For example, a long, hard run might have a TSS of 150, while an easy recovery ride might only be 30.
  • Acute Training Load (ATL): This is your Fatigue Score, calculated as a weighted average of your TSS over the past 7 days. It reflects how much stress your body is currently under.
  • Chronic Training Load (CTL): This represents your long-term fitness level, calculated as a weighted average of your TSS over the past 42 days.
  • Training Stress Balance (TSB): This is the difference between your CTL and ATL. A positive TSB means you’re well-rested, while a negative TSB indicates fatigue.

What Constitutes a High Fatigue Score?

A high fatigue score is relative and depends on your fitness level, training history, and goals. However, some general guidelines can help you interpret your score:

  • Low Fatigue (ATL < 30): You’re likely undertraining or in a recovery phase.
  • Moderate Fatigue (ATL 30-70): This is the sweet spot for most athletes, indicating consistent training without excessive stress.
  • High Fatigue (ATL > 70): Your body is under significant stress, which could lead to overtraining if not managed properly.

For elite athletes, a high fatigue score might be 100 or more, while beginners might feel overwhelmed at 50. The key is to understand your own thresholds and adjust your training accordingly.


The Science Behind Fatigue

Fatigue isn’t just a number; it’s a complex physiological response to training. Here’s what’s happening inside your body when your fatigue score is high:

  1. Muscle Damage: Intense workouts cause micro-tears in your muscle fibers, leading to soreness and reduced performance.
  2. Energy Depletion: Glycogen stores in your muscles and liver are depleted, leaving you feeling drained.
  3. Central Nervous System Fatigue: Your brain and nervous system are overworked, affecting coordination, focus, and motivation.
  4. Hormonal Imbalance: Prolonged stress can disrupt hormones like cortisol and testosterone, impacting recovery and performance.
  5. Immune Suppression: Overtraining can weaken your immune system, making you more susceptible to illness.

The Benefits of a High Fatigue Score

While a high fatigue score might sound alarming, it’s not always a bad thing. In fact, it’s often a sign that you’re pushing your limits and making progress. Here’s why:

  1. Adaptation: Stress is necessary for adaptation. By challenging your body, you stimulate improvements in strength, endurance, and efficiency.
  2. Peak Performance: Periods of high fatigue are often followed by tapering, where you reduce training load to allow your body to recover and perform at its best.
  3. Mental Toughness: Pushing through fatigue builds resilience and mental fortitude, which are crucial for race day.

The Risks of a High Fatigue Score

On the flip side, consistently high fatigue scores can lead to overtraining syndrome, a condition characterized by prolonged fatigue, decreased performance, and increased risk of injury. Here are some warning signs to watch for:

  1. Persistent Fatigue: Feeling tired all the time, even after rest.
  2. Decreased Performance: Struggling to hit your usual paces or power outputs.
  3. Mood Changes: Irritability, depression, or lack of motivation.
  4. Frequent Illness: Catching colds or infections more often than usual.
  5. Sleep Issues: Trouble falling asleep or staying asleep.

How to Manage a High Fatigue Score

If your fatigue score is consistently high, it’s time to take action. Here are some strategies to manage fatigue and prevent overtraining:

  1. Prioritize Recovery: Incorporate rest days, easy workouts, and active recovery into your training plan.
  2. Sleep Well: Aim for 7-9 hours of quality sleep per night to support recovery.
  3. Fuel Your Body: Eat a balanced diet rich in carbohydrates, protein, and healthy fats to replenish energy stores and repair muscles.
  4. Hydrate: Stay hydrated to support metabolic processes and reduce fatigue.
  5. Listen to Your Body: If you’re feeling unusually tired or sore, it’s okay to adjust your training or take an extra rest day.

The Role of Training Peaks in Fatigue Management

Training Peaks isn’t just a tool for tracking fatigue; it’s also a guide for managing it. Here’s how you can use the platform to stay on top of your fatigue levels:

  1. Monitor Trends: Keep an eye on your ATL, CTL, and TSB to understand how your fatigue is changing over time.
  2. Plan Tapering: Use the Performance Management Chart to plan tapering phases before key races or events.
  3. Adjust Workouts: If your fatigue score is too high, consider reducing the intensity or duration of upcoming workouts.
  4. Communicate with Your Coach: Share your data with your coach to get personalized advice and adjustments.

The Psychological Aspect of Fatigue

Fatigue isn’t just physical; it’s also mental. A high fatigue score can take a toll on your motivation and confidence. Here’s how to stay mentally strong:

  1. Set Realistic Goals: Break your training into manageable chunks and celebrate small victories along the way.
  2. Practice Mindfulness: Techniques like meditation and deep breathing can help you stay focused and calm.
  3. Stay Positive: Remind yourself why you started and visualize your success.
  4. Seek Support: Lean on friends, family, or a coach for encouragement and accountability.

The Bigger Picture: Balancing Fatigue and Fitness

Ultimately, fatigue is a natural part of the training process. The goal isn’t to avoid it entirely but to manage it effectively. By understanding your fatigue score and listening to your body, you can strike the right balance between pushing your limits and staying healthy.


FAQs

Q1: What’s the difference between Fatigue Score and TSS? A: Fatigue Score (ATL) is a measure of short-term training stress, while TSS is the stress score for an individual workout.

Q2: Can a high fatigue score improve my performance? A: Yes, but only if followed by adequate recovery. High fatigue stimulates adaptation, but without rest, it can lead to overtraining.

Q3: How often should I check my fatigue score? A: Regularly, but not obsessively. Weekly check-ins are usually sufficient to monitor trends.

Q4: What should I do if my fatigue score is too high? A: Prioritize recovery by reducing training load, getting more sleep, and focusing on nutrition.

Q5: Is fatigue score the same for all sports? A: No, fatigue scores vary depending on the sport, intensity, and individual factors. A high score for a cyclist might be different from that of a runner.


In conclusion, a high fatigue score on Training Peaks is both a challenge and an opportunity. By understanding what it means and how to manage it, you can turn fatigue into a powerful tool for achieving your fitness goals. So, the next time you feel like you’re running a marathon in your sleep, remember: it’s all part of the journey.