Mental fatigue poses a significant threat to athletic performance, affecting areas such as decision-making, motor skills, strength, and endurance. Research indicates that even when physiological indicators remain unchanged, mental fatigue can lead to notable declines in both physical and cognitive performance. Therefore, it is essential to use a combination of objective and subjective measures to assess fatigue accurately. Relying solely on subjective indicators, like athlete feedback or visible signs of tiredness, can be misleading. Athletes may be experiencing more fatigue than can be seen with the naked eye. This can result in unknowingly giving athletes excessive training loads and inadvertently harming performance.

This guide presents simple protocols that utilize the Psychomotor Vigilance Task - Brief (PVT-B), Psychomotor Fatigue Threshold Test (PFTT), and the Rating of Mental Fatigue (RMF) Scale within the Soma Analytics platform. By implementing these tools, coaches and athletes can effectively monitor and manage mental fatigue to optimize performance.

Cognitive load refers to the mental effort required to perform a task. In the context of athletic training, it’s crucial to balance cognitive load to optimize performance. But how do we determine the right amount?

Without tracking mental fatigue, it’s challenging to know whether an athlete is being underloaded or overloaded. Without a clear protocol and the right testing tools, coaches and trainers might unknowingly push athletes too hard, or not push them hard enough. Leading to either over or under training. Overtraining occurs when the cognitive training exceeds an athlete’s capacity, potentially causing burnout or decreased performance. Conversely, cognitively under loading means the athlete isn’t being challenged enough to improve.

Mental fatigue is often silent—it doesn’t always show obvious signs but can significantly impair performance. Without monitoring mental fatigue at the beginning and end of each training session, you risk:

Underloading: If pre- and post-session performance metrics show no change, athletes might not be experiencing enough mental stress to drive improvement. This is like going through a workout without pushing yourself, leading to stagnant progress.

Overloading: Excessive cognitive load can accumulate, especially during intensive training periods. This can impair both mental and physical performance, jeopardizing an athlete’s readiness for competition.

Different training phases require different approaches to cognitive load:

Heavy Season: During periods with intense competition schedules, cognitive training loads might be lighter to maintain optimal performance. Monitoring ensures that any mental fatigue from physical training doesn’t accumulate to harmful levels.

Off-Season or Pre-Season: These phases are ideal for pushing harder, creating sufficient cognitive stress to promote adaptation and improvement. However, it’s essential to ensure athletes can recover adequately between sessions.

Both the PVT-B/PVT and PFTT are powerful tools designed to monitor mental fatigue, but their applications differ based on specific training objectives.

The PVT-B/PVT (Psychomotor Vigilance Task - Brief) is most effectively used when the primary goal is to monitor mental fatigue. This test is specifically designed to assess how mental fatigue affects cognitive alertness and reaction times. By administering the PVT-B/PVT, you can gain detailed insights into an athlete's mental fatigue levels and overall cognitive readiness, making it an essential tool for evaluating how well an athlete can maintain focus and respond to stimuli under conditions of mental strain.

Example of PVT-B in Action

In the video example below, you can see how challenging the training session was.

📍 At the Start (21:19) – Fresh & Focused

• Reaction Time: 356ms (quick responses).

• Accuracy: 100% (perfect focus).

• Variation: 13% (consistent performance).

• Lapses: 1 (minimal attention errors).

📍 At the End (22:30) – Mentally Fatigued

• Reaction Time: 372ms (slower responses).

• Accuracy: 100% (still perfect, but slowing down).

• Variation: 20% (less consistent reactions).

• Lapses: 4 (more frequent attention errors).

By monitoring PVT-B data, you can see that the session was challenging enough to induce mental fatigue. Ideally, you’d want to see PVT-B return to baseline levels by the next session. If pre-session values rise over the week, this may indicate the athlete needs more recovery time.

Keeping an eye on mental fatigue levels with the PVT-B is a quick and effective test. We recommend tracking PVT-B over at least a month to establish a normal baseline for your athletes and adjust training loads accordingly.

The PFTT (Psychomotor Fatigue Threshold Test) is best suited for identifying the precise moment an athlete crosses the psychomotor fatigue threshold during physical training. As physical intensity increases, cognitive performance initially improves, reaching a peak where the brain functions at its highest capacity. However, beyond this peak, cognitive functions, such as reaction time, begin to decline, even if the body continues to perform physically. The PFTT helps pinpoint this critical threshold, allowing coaches to optimize training programs. This might involve keeping the athlete within their optimal performance zone or deliberately pushing them beyond it to enhance their cognitive resilience. Research suggests that this threshold is not fixed and can be improved with consistent, targeted training.

Example of PFTT in Action

In the video below, you can see how the athlete’s performance changed over time during training.

📍 At the Start (10:38) – Strong Performance

• Reaction Time: 331ms (quick).

• Accuracy: 96% (very high).

• Variation: 15% (consistent performance).

• HRV: 100.70 (good).

• The athlete is performing well.

📍 Peak Performance (10:51) – Best Cognitive State

• Reaction Time: 310ms (fastest reaction time).

• Accuracy: 96% (still high).

• Variation: 14% (most stable performance).

• HRV: 104.61 (good).

• This is where the athlete is functioning at their highest capacity.

📍 Crossing the Fatigue Threshold (11:05) – Cognitive Decline Begins

• Reaction Time: 348ms (slower responses).

• Accuracy: 84% (dropped significantly).

• Variation: 22% (less consistent reactions).

• HRV: 67.75 (diminished).

• The athlete has crossed the Psychomotor Fatigue Threshold (PFT), meaning their brain is now struggling to keep up, even though their body can still perform.

Monitor Mental Fatigue: Use the PVT-B to assess mental fatigue after cognitive training sessions.

Readiness: Implement this test to evaluate an athlete's mental readiness and detect signs of mental fatigue.

Identify Psychomotor Fatigue Threshold: Use the PFTT to pinpoint the exact moment an athlete crosses the psychomotor fatigue threshold during physical training.

Optimize Training Programs: Best for determining when cognitive performance peaks and begins to decline as physical intensity rises. This allows you to maintain athletes at their optimal level or push them beyond it to enhance cognitive capacity.

The PVT-B task is a reliable tool for evaluating mental fatigue. By tracking key metrics, you can gain a comprehensive understanding of an athleteʼs cognitive state and tailor training or recovery strategies accordingly.

By understanding these metrics, you can fine-tune training programs, manage recovery, and help athletes maintain peak performance.

The PFTT helps identify the sweet spot for cognitive and physical performance by monitoring reaction times as physical intensity increases.

Understanding these phases helps coaches maintain athletes in their optimal zone or strategically push beyond it for targeted training benefits.

The RMF Scale, accessible on the Soma Analytics platform, is specifically designed to subjectively assess an athlete’s mental fatigue after they engage in cognitive tasks within Soma NPT. This scale enables athletes to self-report their level of tiredness, providing valuable insights that might not be fully captured by objective measurements alone.

The RMF Scale can be easily integrated into athletes’ training programs using the Soma Analytics plan builder. When an athlete completes a cognitive task within Soma NPT, they immediately complete the RMF Scale, and this data is automatically linked to that specific task. This integration allows coaches to view mental fatigue readings for each task performed during the training session, along with specific fatigue assessments such as the PVT-B and PFTT. This enhances the depth and accuracy of data collection and analysis.

Such detailed information is crucial as it helps identify specific stressors, enabling the adjustment of training programs to better align with an athlete’s capacity and recovery needs.

The RMF Scale quantifies mental fatigue, with higher scores indicating greater perceived mental fatigue by the athlete.

The Psychomotor Vigilance Test (PVT) and PVT-B both measure sustained attention and reaction time, but they differ in key aspects:

Duration:

• PVT: Available in 5-minute or 10-minute versions.

• PVT-B: A shorter 3-minute test.

Lapse Threshold:

• PVT: Responses slower than 500ms are considered lapses.

• PVT-B: A stricter threshold—responses slower than 355ms are lapses.

Interstimulus Interval (ISI) – Delay Between Stimuli:

• PVT: Longer ISI, meaning more time between reaction prompts.

• PVT-B: Shorter ISI, leading to a faster-paced test.

PVT-B is designed for quicker assessments with a higher cognitive load due to reduced response time, while the full PVT provides a more comprehensive evaluation of vigilance over a longer period.

What Is a Lapse?

Lapses are key indicators of mental fatigue in athletes. They represent moments when an athlete responds much slower than usual, often due to a lack of focus. When mental fatigue sets in, athletes tend to have slower reaction times, more variation in their responses, and a higher number of lapses. Therefore, tracking lapses helps measure mental fatigue. If the number of lapses increases, it’s a warning to pay closer attention to the athlete’s data.