Mental FatigueNCT07323810
Monitoring the Effect of Mental Fatigue on Physical Performance Using Wearable Sensors and Physiological Parameters
A study testing Mental Fatigue in people with Mental Fatigue, run by Vrije Universiteit Brussel at 1 site in Belgium.
Trial summary
Mental fatigue (MF) negatively affects both cognitive and physical performance, increasing the risk of errors in high-stakes environments such as sports and surgery. Traditional methods to assess MF rely on subjective self-report scales, which are prone to bias, or on complex brain measurements (e.g. Read more about this study
- Who is it for?
- Ages 18 to 35 yearsHealthy volunteers can take part
- Conditions the study is for
- Mental Fatigue
- What is being tested?
- Mental Fatigue
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteBelgium
- Study dates
- 3 Dec 2025to Sep 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 35 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy (no neurological, cardiovascular or musculoskeletal disorders of any kind)
- Male or female
- No prior knowledge of the concept of MF
- No medication
- Non-smoker
- 18-35 years of age
- Experienced runners: (≥15km/week and/or ≥2u/week during the last 6 months)
Who cannot join
- Injuries in the past 6 months, affecting running performance
- Suffering from a chronic health condition (could be neurological, cardiovascular, internal or musculoskeletal)
- Participating in any concomitant care or research trials
- History of suffering from any mental/psychiatric disorders
- Use of medication
- Use of caffeine and heavy efforts 24 hours prior each trial
- Suffering from colour vision deficiencies
- Not eating a standardized meal, the morning of each trial and the evening before each trial
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Belgium1 site, 1 recruiting
- Recruiting
Brussels Labo voor Inspanning en Topsport
Brussels, 1050
Emilie Schampheleer, Msc, 26292222 ext. +32, emilie.schampheleer@vub.be
About this study
Mental fatigue (MF) negatively affects both cognitive and physical performance, increasing the risk of errors in high-stakes environments such as sports and surgery. Traditional methods to assess MF rely on subjective self-report scales, which are prone to bias, or on complex brain measurements (e.g. EEG) that are impractical outside laboratory settings. This study aims to develop a real-time, objective monitoring method for MF using wearable physiological sensors. The study will recruit healthy, trained runners (18-35 years old) who will complete both an MF-inducing cognitive task (Stroop test) and a control condition (watching a documentary) in a randomized, counterbalanced, crossover design. Heart rate variability, respiration rate, and pupil metrics will be continuously recorded using wearable devices. Machine learning models will be used to predict MF-level as well as the effect of MF on physical performance (5-km time trial on a treadmill) using the physiological data as input.
- Conditions
- Mental Fatigue
- Being tested
- Mental Fatigue
- Keywords
- Fatigue, Performance, Physiology, Wearables
- Medical subject headings
- Mental Fatigue, Fatigue
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Mental FatigueBehavioural
Mental fatigue (MF) is a psychobiological state characterized by feelings of tiredness and/or a measurable decline in performance following prolonged or intense cognitive activity.
| Study group | Role | What they receive |
|---|---|---|
| Mental Fatigue Condition | Experimental | The mental fatigue task will involve a modified Stroop test, adapted from previous research. Words will appear on the screen in 34-point font for 1000 milliseconds, with the inter-stimulus interval personalized based on each participant's Stroop max test performance. Stroop task duration will be 60 minutes for every participant. Participants will be instructed to respond as quickly and accurately as possible. Receives: Behavioral: Mental Fatigue |
| Control condition | No intervention | The control task will consist of watching a pre-approved, emotionally neutral 60-minute documentary. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Heart rate variability time-domain parameters
Root mean square of successive differences [RMSSD], standard deviation of normal-to-normal intervals [SDNN] in milliseconds.
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Heart rate variability frequency-domain parameters
Low-frequency (LF), High-frequency (HF) in milliseconds squared (ms²) and Low/high-frequency ratio [LF/HF]
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Respiration rate
Respiration rate (RR) will be measured as the number of breaths per minute (breaths/min)
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Pupil diameter
Pupil diameter (PD) will be measured in millimeters (mm) as an index of autonomic nervous system activity.
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Blinking rate
Blinking rate (BR) will be measured as the number of spontaneous blinks per minute (blinks/min)
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Eyelid opening
Eyelid opening (EO) will be measured as the vertical distance between the upper and lower eyelid in millimeters (mm).
Measured: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Cognitive Performance Accuracy
Cognitive performance will be evaluated using a Go/No-Go task. The task begins with a general instruction screen, followed by the simultaneous presentation of two types of stimuli: a Go or No-Go signal and a left or right directional indicator. This results in four possible combinations: GoRight, GoLeft, NoGoRight, and NoGoLeft. When a Go signal appears, participants must respond by pressing the arrow key corresponding to the left or right direction. In contrast, when a No-Go signal is displayed, participants must withhold any response, regardless of the directional cue. This paradigm is designed to assess attention, response inhibition, working memory, and executive functions, all of which are known to be negatively affected by MF. Accuracy in percentage (%) of correct answers on this Go/No-Go task as well as accuracy during the Stroop intervention task will be measured.
Measured: At baseline (pre-intervention), during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day (approximately 70 minutes total).
Cognitive Performance Reaction Time
Cognitive performance will be evaluated using a Go/No-Go task. The task begins with a general instruction screen, followed by the simultaneous presentation of two types of stimuli: a Go or No-Go signal and a left or right directional indicator. This results in four possible combinations: GoRight, GoLeft, NoGoRight, and NoGoLeft. When a Go signal appears, participants must respond by pressing the arrow key corresponding to the left or right direction. In contrast, when a No-Go signal is displayed, participants must withhold any response, regardless of the directional cue. This paradigm is designed to assess attention, response inhibition, working memory, and executive functions, all of which are known to be negatively affected by MF. Reaction time (RT) will be measured in milliseconds (ms) as the latency between stimulus onset and the participant's behavioral response (button press) on the Go/No-Go task and during the Stroop intervention task.
Measured: At baseline (pre-intervention), during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day (approximately 70 minutes total).
Physical performance: Time to Completion
Participants will perform a 5-km running time trial on a treadmill to assess endurance performance under MF. The treadmill will be set at a 1% gradient, following established protocols to replicate outdoor running conditions. Before beginning the time trial, participants will complete a standardized warm-up for 5 minutes. To maintain self-paced running conditions, participants will receive real-time feedback on the distance covered but will not be provided with information about running speed or elapsed time. Researchers will remain present but will not offer verbal encouragement or pacing cues to ensure that the effort remains internally regulated. Once the 5-km distance is completed, participants will immediately stop running and step onto the treadmill's side platforms. The total time elapsed will be recorded.
Measured: Immediately after completion of the 60-minute cognitive intervention, during a single 5-km treadmill time trial on the study day (approximately 20 minutes).
Secondary outcomes (7)
Subjective feeling of Mental Fatigue
The Mental Fatigue Visual Annalogue Scale (0-10cm) will assess how mentally fatigued the participant is feeling (100 point VAS scale), and ranges from 'not at all' to 'completely exhausted'.
Measured: At baseline (pre-intervention), every 5 minutes during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day.
Mood
The Brunel Mood Scale (BRUMS) will be used to indicate mood, and serve as a control measure for both arousal as well as boredom. It features 24 mood descriptors (divided into 6 subscales (i.e. anger, confusion, depression, fatigue, tension and vigor)), where participants have to give a value for every mood on a 5-point Likert scale (i.e. 0=not at all to 4 = extremely) responding to the question: "how do you feel right now?"
Measured: At baseline, prior to the start of each experimental and control trial on the study day.
Motivation
Moti-VAS: Motivation will be assessed using a VAS. Participants will be asked "How motivated do you feel for the upcoming task", and will be instructed to rate their answer on a 10cm line, with the statements "not at all" and "extremely motivated" at opposite ends of this line.
Measured: At baseline (pre-intervention) and immediately after completion of the 60-minute cognitive intervention on the study day.
Sleepiness
The Karolinska Sleepiness Scale (KSS) will be conducted. This 10-point scale measures the subjective level of sleepiness and goes from 1 = 'extremely alert' to 10 = 'extremely sleepy, falls asleep all the time'.
Measured: At baseline (pre-intervention) and immediately after completion of the 60-minute cognitive intervention on the study day.
Physical fatigue
To measure subjective feeling of physical fatigue, a P-VAS scale (0-10 cm) will be administered before each physical performance test to check the level of subjective physical fatigue of the participants. Participants will be asked to rate their general physical fatigue on a 10 cm line ranging from "not at all" to "completely exhausted".
Measured: Immediately prior to the physical performance test on the study day.
Perceived physical exertion
Rating of Perceived Exertion (RPE) will be measured using the Borg CR100® scale, which ranges from 0 to 100, with 0 representing "no exertion at all" and 100 representing "maximal exertion". Higher scores indicate greater perceived effort. Participants will be asked to provide an RPE rating at the end of each kilometre during the 5-km time trial.
Measured: During the 5-km treadmill time trial, assessed at the end of each kilometer on the study day.
Pacing
Pacing will be assessed as the pattern of speed regulation across the 5-km time trial. Running speed (km/h) will be recorded continuously and summarized per kilometre to characterize pacing strategy (positive, negative, or even pacing). Relative speed will also be expressed as a percentage of average trial speed. Alongside total completion time, pacing will serve as an indicator of how participants distribute effort under self-paced running conditions.
Participants will be asked every kilometer how fast they think they are running at that moment to verify any discrepancies with their actual running speed and observe whether there is a learning or condition effect.
Measured: During the 5-km treadmill time trial, assessed at the end of each kilometer on the study day.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Jan 2026
- Study start3 Dec 2025
- Primary completionSep 2026 (estimated)
- Study completionSep 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Mental FatigueStudies of the same condition, open and under way.
- More trials run by Vrije Universiteit BrusselThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vrije Universiteit Brussel
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Bart Roelands, Vrije Universiteit Brussel
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07323810
- Sponsor's protocol ID
- EC-2025-113
- Status last verified
- Aug 2025
- First submitted
- 22 Aug 2025
- Last updated
- 18 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 18 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Monitoring the Effect of Mental Fatigue on Physical Performance Using Wearable Sensors and Physiological Parameters
- ClinicalTrials.gov ID
- NCT07323810
- Acronym / sponsor ID
- EC-2025-113
- Conditions
- Mental Fatigue
- Keywords
- Fatigue, Performance, Physiology, Wearables
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Vrije Universiteit BrusselUniversity, hospital or other
- Study start
- 3 Dec 2025 (actual)
- Primary completion
- Sep 2026 (estimated)
- Study completion
- Sep 2026 (estimated)
- First posted
- 7 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Mental fatigue (MF) negatively affects both cognitive and physical performance, increasing the risk of errors in high-stakes environments such as sports and surgery. Traditional methods to assess MF rely on subjective self-report scales, which are prone to bias, or on complex brain measurements (e.g. EEG) that are impractical outside laboratory settings. This study aims to develop a real-time, objective monitoring method for MF using wearable physiological sensors. The study will recruit healthy, trained runners (18-35 years old) who will complete both an MF-inducing cognitive task (Stroop test) and a control condition (watching a documentary) in a randomized, counterbalanced, crossover design. Heart rate variability, respiration rate, and pupil metrics will be continuously recorded using wearable devices. Machine learning models will be used to predict MF-level as well as the effect of MF on physical performance (5-km time trial on a treadmill) using the physiological data as input.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Mental Fatigue Condition | Experimental | Behavioral: Mental FatigueThe mental fatigue task will involve a modified Stroop test, adapted from previous research. Words will appear on the screen in 34-point font for 1000 milliseconds, with the inter-stimulus interval personalized based on each participant's Stroop max test performance. Stroop task duration will be 60 minutes for every participant. Participants will be instructed to respond as quickly and accurately as possible. |
| Control condition | No intervention | –The control task will consist of watching a pre-approved, emotionally neutral 60-minute documentary. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Healthy (no neurological, cardiovascular or musculoskeletal disorders of any kind)
- Male or female
- No prior knowledge of the concept of MF
- No medication
- Non-smoker
Key exclusion criteria (8 listed)
- Injuries in the past 6 months, affecting running performance
- Suffering from a chronic health condition (could be neurological, cardiovascular, internal or musculoskeletal)
- Participating in any concomitant care or research trials
- History of suffering from any mental/psychiatric disorders
- Use of medication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Mental FatigueMental fatigue (MF) is a psychobiological state characterized by feelings of tiredness and/or a measurable decline in performance following prolonged or intense cognitive activity. | Behavioural | Mental Fatigue Condition |
Primary outcome
Heart rate variability time-domain parameters
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Root mean square of successive differences [RMSSD], standard deviation of normal-to-normal intervals [SDNN] in milliseconds.
Heart rate variability frequency-domain parameters
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Low-frequency (LF), High-frequency (HF) in milliseconds squared (ms²) and Low/high-frequency ratio [LF/HF]
Respiration rate
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Respiration rate (RR) will be measured as the number of breaths per minute (breaths/min)
Pupil diameter
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Pupil diameter (PD) will be measured in millimeters (mm) as an index of autonomic nervous system activity.
Blinking rate
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Blinking rate (BR) will be measured as the number of spontaneous blinks per minute (blinks/min)
Eyelid opening
Time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).
Eyelid opening (EO) will be measured as the vertical distance between the upper and lower eyelid in millimeters (mm).
Cognitive Performance Accuracy
Time frame: At baseline (pre-intervention), during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day (approximately 70 minutes total).
Cognitive performance will be evaluated using a Go/No-Go task. The task begins with a general instruction screen, followed by the simultaneous presentation of two types of stimuli: a Go or No-Go signal and a left or right directional indicator. This results in four possible combinations: GoRight, GoLeft, NoGoRight, and NoGoLeft. When a Go signal appears, participants must respond by pressing the arrow key corresponding to the left or right direction. In contrast, when a No-Go signal is displayed, participants must withhold any response, regardless of the directional cue. This paradigm is designed to assess attention, response inhibition, working memory, and executive functions, all of which are known to be negatively affected by MF. Accuracy in percentage (%) of correct answers on this Go/No-Go task as well as accuracy during the Stroop intervention task will be measured.
Cognitive Performance Reaction Time
Time frame: At baseline (pre-intervention), during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day (approximately 70 minutes total).
Cognitive performance will be evaluated using a Go/No-Go task. The task begins with a general instruction screen, followed by the simultaneous presentation of two types of stimuli: a Go or No-Go signal and a left or right directional indicator. This results in four possible combinations: GoRight, GoLeft, NoGoRight, and NoGoLeft. When a Go signal appears, participants must respond by pressing the arrow key corresponding to the left or right direction. In contrast, when a No-Go signal is displayed, participants must withhold any response, regardless of the directional cue. This paradigm is designed to assess attention, response inhibition, working memory, and executive functions, all of which are known to be negatively affected by MF. Reaction time (RT) will be measured in milliseconds (ms) as the latency between stimulus onset and the participant's behavioral response (button press) on the Go/No-Go task and during the Stroop intervention task.
Physical performance: Time to Completion
Time frame: Immediately after completion of the 60-minute cognitive intervention, during a single 5-km treadmill time trial on the study day (approximately 20 minutes).
Participants will perform a 5-km running time trial on a treadmill to assess endurance performance under MF. The treadmill will be set at a 1% gradient, following established protocols to replicate outdoor running conditions. Before beginning the time trial, participants will complete a standardized warm-up for 5 minutes. To maintain self-paced running conditions, participants will receive real-time feedback on the distance covered but will not be provided with information about running speed or elapsed time. Researchers will remain present but will not offer verbal encouragement or pacing cues to ensure that the effort remains internally regulated. Once the 5-km distance is completed, participants will immediately stop running and step onto the treadmill's side platforms. The total time elapsed will be recorded.
7 secondary outcomes
Subjective feeling of Mental Fatigue
Time frame: At baseline (pre-intervention), every 5 minutes during the 60-minute cognitive intervention, and immediately after completion of the intervention on the study day.
Mood
Time frame: At baseline, prior to the start of each experimental and control trial on the study day.
Motivation
Time frame: At baseline (pre-intervention) and immediately after completion of the 60-minute cognitive intervention on the study day.
Sleepiness
Time frame: At baseline (pre-intervention) and immediately after completion of the 60-minute cognitive intervention on the study day.
Physical fatigue
Time frame: Immediately prior to the physical performance test on the study day.
Perceived physical exertion
Time frame: During the 5-km treadmill time trial, assessed at the end of each kilometer on the study day.
Pacing
Time frame: During the 5-km treadmill time trial, assessed at the end of each kilometer on the study day.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Aug 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Mental Fatigue in people with Mental Fatigue, run by Vrije Universiteit Brussel at 1 site in Belgium.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 18 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Belgium. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Emilie Schampheleer, Msc (26292222 ext. +32, emilie.schampheleer@vub.be), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Heart rate variability time-domain parameters (time frame: Continuously during the cognitive intervention and control condition on the study day (approximately 75 minutes).). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 18 Aug 2026; AzTrials last refreshed its copy on 7 Nov 2026.