Mental Fatigue

This study will investigate the acute effects of mental fatigue on lower-extremity muscle strength and limb symmetry in healthy young adults. Participants will complete lower-extremity strength testing before and after a standardized computer-based mental fatigue protocol involving tasks of attention, reaction time, concentration, and working memory. Muscle strength and limb symmetry will be assessed using isokinetic dynamometry, with muscle activity measured using surface electromyography. Participants will also complete subjective measures of mental fatigue, sleepiness, mental effort, and perceived physical exertion. Heart rate will be monitored throughout the study, and brain activity may be assessed during cognitive tasks. The study will determine whether acute mental fatigue is associated with changes in muscle strength, limb symmetry, and neuromuscular performance.

Mental fatigue occurs in many diseases and the reasons are mostly unknown. The investigators hypothesize that remaining mental fatigue after restored euthyroidism in Graves' disease is an autoimmune complication. This is a confirmatory study of the biomarkers from ImmunoGraves WP1 in which immunological markers with possible association with mental fatigue in Graves' disease are explored. In ImmunoGraves WP2, 310 patients with Graves' disease are assessed for symptoms of mental fatigue, quality of life, anxiety and depression, self-evaluated stress, coping strategies, personality traits, eye symptoms and background variables. Participants are examined in hyperthyroidism at inclusion, within three weeks from diagnosis, and in euthyroidism after 15 months. Serum and cerebrospinal fluid (in a subsample of participants) is collected at both visits and will be evaluated for the immunological markers identified in WP1 as well as for thyroid hormones, thyroid autoantibodies and biomarkers indicating organic and structural nerve damage. Significant predictors for mental fatigue will be identified by logistic regression. To assess functional changes in the brain, magnetoencephalography will be performed in a subset of patients and in healthy controls at inclusion and after 15 to 18 months. Combined with magneto resonance imaging (MRI), magnetoencephalography gives information on neuronal activation during attention testing.

This observational, prospective, within-subject study will examine how the volume and timing of physiotherapy and psychology classes and exams at LUDES Institute influence mental fatigue, sleepiness, motivation, executive function, and physical performance in university students. Approximately 30 students aged 18 years or older will complete repeated assessments at baseline (no formal academic activities), during a regular theoretical class, and, when feasible, during an exam session. At each time point, participants will undergo non-invasive measurements including self-reported mental fatigue (visual analogue scale), sleepiness (Karolinska Sleepiness Scale), motivation (Motivational States Scale), cognitive performance (Encephalapp Stroop task), and handgrip strength and endurance with perceived exertion ratings, alongside sleep diaries and wrist actigraphy. The primary endpoint is the pre-to post-session change in mental fatigue and cognitive performance, with secondary endpoints capturing sleep and circadian metrics, physical performance, motivation, and exam grades. Mixed-effects models will be used to test how class/exam duration, time of day, sleep quantity and quality, and chronotype relate to psychobiological responses, with the goal of informing evidence-based scheduling and workload policies in health-profession education.

This study examines whether short-term mental fatigue and different jump instructions affect how high people can jump. Thirty-two physically active university students will complete two testing sessions in random order: one after a 30-minute mentally tiring computer task and one after a 30-minute relaxing video. In both sessions, participants will perform vertical jumps while receiving one of three types of instructions: no special instruction, focusing on their own body movements, or focusing on pushing the ground away. The study will compare jump height across these conditions to better understand how mental tiredness and coaching cues affect jumping performance, which may help coaches and athletes design better training and competition preparation.

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.

Objective: To investigate the effects of brain endurance training on improving motor skill learning in adolescents with mild mental fatigue. Methods: Fifty-eight adolescents experiencing mild mental fatigue were recruited. A 6-week training program was conducted using a 2 (BET group, control group) × 2 (pre- and post-Stroop task) × 3 (0, 3, 6 weeks) mixed-design experimental design. Assessments included basketball free throws, the Visual Analog Scale (VAS-MF), the 3-minute Psychomotor Vigilance Test (PVT-B), the Borg Rating of Perceived Exertion (RPE) to assess performance before and after a 30-minute Stroop task.

Objective To investigate the independent and combined effects of caffeine and vitamin C on maximal strength and strength endurance in female adolescents with mild mental fatigue. Methods A randomised, double-blind, crossover experimental design was adopted. Forty female college students presenting mild mental fatigue were recruited as participants. Each participant completed five laboratory sessions in total. The first session determined their one-repetition maximum (1RM) for bench press and back squat. The remaining four experimental sessions involved four supplement interventions administered in random order: placebo control, vitamin C (VC) alone, caffeine (CAF) alone, and combined caffeine plus vitamin C (CAF+VC). A one-week washout interval was arranged between every two supplementation trials. In each test session, participants completed a 45-min Stroop task to induce mental fatigue prior to exercise assessments. Measurements included the Visual Analogue Scale for Mental Fatigue (VAS-MF), 1RM bench press and squat performance, as well as the maximal number of repetitions at 65% 1RM for both movements. Immediately after the strength endurance test, perceived exertion and muscle pain were rated. Blood glucose and blood lactate concentrations were sampled before and after all exercise protocols. Supplementation was administered 1 hour prior to testing: a standard caffeine dosage of 3.0 mg per kg body mass and a single 500 mg dose of vitamin C were provided for the corresponding intervention groups.

The goal of this study is to comprehend how mental fatigue could affect human gait. The main questions to answer are: * Does mental fatigue change how people walk? * How long does it take for walking patterns to return to normal after mental fatigue sets in? * What role do constructs like boredom, sleepiness, and motivation play in this relationship? To achieve this, participants will take part in the experiment, split into two sessions: Day 1 (online, about 25 minutes): Practice session. Participants will practice a computer task that will be used to induce mental fatigue in the next session. Day 2 (in-person, about 1.5 to 2 hours): Participants will wear several wearable sensors: motion sensors on their legs, feet, and back, sensor insoles in their shoes, a cap that measures brain activity, and glasses that track eye movement. After sensor placement, participants will walk in a straight line for 10 meters to measure their normal walking pattern. They will then complete a 32-minute computer task designed to induce mental fatigue. Afterward, participants will walk in a straight line for 10 meters again, rest for 3 minutes, and repeat this walk-and-rest cycle 3 more times. Participants will also answer short questions about how tired, bored, and alert they feel throughout the session.

This randomized crossover study investigates the effects of mental fatigue on postural control and spinal reflex excitability in healthy physically active adults aged 18-35 years. Participants will complete two experimental conditions: a mentally fatiguing Stroop task and a control condition involving passive documentary watching, separated by at least 48 hours. Postural control will be assessed using force plate measures of center of pressure displacement during bipedal and unipedal stance, with and without concurrent cognitive dual-tasking. In parallel, spinal reflex excitability will be evaluated using H-reflex recordings from the triceps surae muscles across sitting and standing postures. The primary aim is to determine whether mental fatigue increases postural sway, particularly in more challenging balance conditions such as single-leg stance. The secondary aim is to examine whether mental fatigue alters the normal modulation of spinal reflex excitability across progressively demanding postural tasks. Additional biomechanical and neuromuscular measures, including EMG activity and hip kinematics, will be recorded to provide insight into underlying control mechanisms. The study will include approximately 26 participants, with each serving as their own control. Data will contribute to understanding how cognitive fatigue influences balance control and spinal-level neuromuscular regulation.

Mental fatigue (MF) is known to impair cognitive performance and may negatively affect physical performance. While its effects on lower-extremity functional performance have been investigated, little is known about the influence of MF on upper-extremity physical performance tests commonly used in sports and rehabilitation settings. This randomized crossover study will investigate the effects of experimentally induced mental fatigue on upper-extremity physical performance in 16 healthy physically active adults. Participants will complete both a mental fatigue condition, involving a prolonged Stroop task, and a control condition consisting of watching an emotionally neutral documentary. Before and after each condition, participants will perform the Upper Quarter Y Balance Test, Reactive Upper Quarter Y Balance Test, Closed Kinetic Chain Upper Extremity Stability Test, and Seated Single-Arm Shot Put Test. Subjective mental fatigue, cognitive performance, motivation, and perceived exertion will also be assessed. The findings will improve understanding of whether mental fatigue influences upper-extremity physical performance test outcomes and may assist clinicians and researchers in interpreting these assessments in sports medicine and rehabilitation contexts.

The proposed project will evaluate the synergistic effects of a nutritional formulation, 'Think Tank' on cognitive performance following exposure to a psychological and physical stressor. Adopting a double-blind repeated measures cross-over design, middle-aged females (40-60 years) will be recruited to take part in a two-stage research study that will examine whether the formulation enhances cognitive performance and subjective well-being following the challenge of a stressor, compared to placebo. Cognitive assessments will examine the impact of the nutritional formulation on working memory, sustained attention, cognitive flexibility and inhibitory control. The study will also assess physiological (heart rate, blood pressure and cortisol) and subjective (well-being, anxiety, positive and negative mood, stress) markers of stress reactivity. The study will also explore levels sleep quality, mental and physical fatigue, effort, productivity, and perceived impact of the intervention.

This study aims to evaluate the effects of music intervention on golf-specific skill performance under mental fatigue. It is a randomised, controlled, double-blind design. The study consists of three main phases: familiarisation with the experimental procedure, baseline testing, and the formal experiment. During the formal experiment, participants will be randomly assigned to one of the following three groups: (MF-Mu Group) Participants undergo a mental fatigue induction task followed by a music intervention; (MF-nMu Group) Participants undergo a mental fatigue induction task but do not receive a music intervention; (CON Group) Participants neither undergo a mental fatigue induction task nor receive a music intervention. The total intervention duration is 45 minutes, consisting of 30 minutes of mental fatigue induction and 15 minutes of music intervention. In conditions where mental fatigue induction or music intervention is not conducted, participants will remain in the same experimental environment and rest quietly for the same duration to control for external confounding factors and ensure experimental consistency. Immediately after the intervention, participants will complete golf skill testing, with the testing site located within a 2 minutes walking distance from the intervention area. Performance outcomes include driving performance, iron shot performance, chipping performance, and putting performance.