The Effect of Different Physical Activity Strategy on Cognitive Efficiency and Mental Fatigue Resistance

Primary outcomes

1. Body mass and body composition (kg)

   Time frame: 2 times in the mornings (day 1 and day 2) of each 3 conditions.

   Body mass and composition (in kilograms) will be evaluated using Tanita Body Composition Analyzer (Japan).

2. Height (m)

   Time frame: 2 times in the mornings (day 1 and day 2) of each 3 conditions.

   Height (in meters) will be measured using a Harpenden anthropometer set (Holtain Ltd, UK).

3. Brain hemodynamic response

   Time frame: Before, immediately after the simulated mental workday, 3 hours after the simulated mental workday, and 12 hours recovery after a simulated mental workday in 3 conditions.

   To measure and evaluate hemodynamic response, a functional near-infrared (fNIRS) device NIRx NIRS Sport2 (Medical Technologies LLC-NIR-Scout, USA) with 8 near-infrared (NIR) radiation sources and 7 photodetectors will be used. The photodetectors record the relative changes in oxygen and oxygenated hemoglobin at 7.81 Hz for both wavelengths. The probes are placed at the manufacturer's specified locations to capture the hemodynamic response of the prefrontal cortex. Live recording will be monitored for 6 minutes.

4. Cognitive performance

   Time frame: Day 1 in 3 different conditions, in 1 condition 8 times for 45 minutes.

   Automated Neuropsychological Assessment Metrics Test Set (ANAM4, version 4; Vista Life Science, Norman, OK, USA). 11 tests will be selected, reflecting the three main cognitive functions - memory, attention and executive function. 11 tests: Procedural RT, Memory search, Spatial processing simultaneous, Matching grids, Matching to sample, Stroop colour word test, Code substitution-learning and Code substitution-delayed, Running memory continuous performance, Continous performance test - traditional. To assess cognitive performance, during a simulated 8-hour mental work day, the subjects will complete a set of cognitive tests 8 times (1 session approximately 45 minutes), after each session there will be a break of approximately 10 minutes. Participants were familiarized with the test battery twice before the experiments.

5. Blood pressure (mmHg)

   Time frame: 11 times during 1 condition (total 33 times).

   Systolic and diastolic blood pressure (in mmHg) will be measured using a blood pressure monitor (Biolight, Patient Monitor S10, Guangdong Biolight Meditech Co, Hamburg, Germany).

6. Heart rate and heart rate variability (ms)

   Time frame: During 1 condition rest measurements in the morning, during brain hemodynamic response (3 times during 1 condition), during every session of 8 hours simultaneous mental work day, total 3 conditions.

   Heart rate (HR) will be recorded using a heart rate monitor (Polar H10, Kempele, Finland) with an electrode strap around the chest throughout the study. 5-min RR interval file will then be analyzed using Kubios HR Variability Analysis Software 2.0 (Biomedical Signal and Medical Image Analysis Group, Department of Applied Physics, University of Kuopio, Kuopio, Finland).

7. Glucose level (mmol/l)

   Time frame: 9 times during 1 condition (total 27 times).

   Glucose level will be measured from capillary blood using Akray glucose analyzer (CONTOUR®PLUS ELITE; Basel, Switzerland). Capillary blood samples will be taken by a qualified medical professional (general practice nurse) at the LSU Institute of Sports Science and Innovation laboratory.

8. Ketones level (mmol/L)

   Time frame: 9 times during 1 condition (total 27 times).

   Ketones level will be measured from capillary blood using a ketone analyzer (The On Call® GK Dual; San Diego, CA; USA). Capillary blood samples will be taken by a qualified medical professional (general practice nurse) at the LSU Institute of Sports Science and Innovation laboratory.

9. Lactate level (mmol/L)

   Time frame: 9 times during 1 condition (total 27 times).

   Lactate levels will be measured using a lactate analyzer (Lactatte Pro 2, Arkray, Koji Konan-cho, Koka-shi, Japan). Capillary blood samples will be taken by a qualified medical professional (general practice nurse) at the LSU Institute of Sports Science and Innovation laboratory.

10. Salivary cortisol concentration (µg/dl)

    Time frame: 11 times during 1 condition (total 33 times).

    The saliva samples will be collected to measure cortisol level (in µg/dl) using an ELISA kits and a Spark multimode microplate reader (Tecan, Austria).

11. Salivary testosterone concentration (µg/dl)

    Time frame: 11 times during 1 condition (total 33 times).

    The saliva samples will be collected to measure cortisol level (in µg/dl) using an ELISA kits and a Spark multimode microplate reader (Tecan, Austria).

12. Salivary female sex hormones concentration (pgmol/L)

    Time frame: 11 times during 1 condition (total 33 times).

    The saliva samples will be collected to measure cortisol level (in µg/dl) using an ELISA kits and a Spark multimode microplate reader (Tecan, Austria).

13. Biochemical urine analysis

    Time frame: 2 times during 1 condition (total 6 times).

    The urine sample will be analyzed in the laboratory using a urine analyzer (PocketChem UA, PU-4010, Arkray, Koji, Konan-cho, Koka-shi, Japan). The analyzer will determine the concentrations of ketones.

14. Pupil diameter (mm)

    Time frame: Before and 3 times during simulated 8 hours workday in 1 condition (total 12 times).

    The dilation and contraction of the pupils of the test subjects' eyes will be recorded using a special camera (Gazepoint, Vancouver, Canada), which will be placed under the computer screen, in front of the subject.

15. The psycho-emotional state: Dundee Stress State Questionnaire (DSSQ)

    Time frame: Before and 8 times during simulated 8 hours workday in 1 condition (total 27 times).

    The psycho-emotional state of the subjects will be assessed using the Dundee Stress State Questionnaire (DSSQ). The DSSQ questionnaire will be used to assess the subjects' motivation in relation to the content of the task, performing a cognitive test battery during the mental work day. 15 questions will be used, e.g.: "the content of the task was interesting", "I wanted to do the task well compared to others", etc. The subject will have to mark the corresponding answers to each question, where 4 (strongly), 3 (very), 2 (a little), 1 (a little), 0 (not at all).

16. The psycho-emotional state: the VAS scale

    Time frame: Before and 8 times during simulated 8 hours workday in 1 condition (total 27 times).

    Motivation, mental fatigue and mind wondering will be assessed using a visual analogue scale (VAS). Subjects will mark their feelings on a 10 centimetres horizontal line from 0 ("completely unmotivated"; "not mentally tired"; "no mind wandering") to 100 ("maximum motivated"; "maximum mental fatigue"; "maximum mind wandering").

17. The psycho-emotional state: Stanford sleepiness scale.

    Time frame: Before and 8 times during simulated 8 hours workday in 1 condition (total 27 times).

    The Stanford Sleepiness Scale will be used to assess subjects' sleepiness. On this scale, subjects will mark their level of sleepiness from 1 "I feel active, efficient, lively, alert or awake" to 7 "I can no longer fight sleep, I will fall asleep quickly; thoughts are like dreams".

18. Measurement of maximal aerobic capacity

    Time frame: Before.

    The maximal aerobic capacity of the subjects will be measured in order to determine the average aerobic load, which will be applied in the study condition "aerobic activity ". The subjects will perform a consistently increasing load until complete fatigue on a bicycle ergometer (Lode B.V., Excalibur Sport, Groningen, Netherlands). Throughout the test, subjects will have their heart rate monitored using a chest strap heart rate monitor (Polar H10, Kempele, Finland). A spirometry system (Metalyzer 3B, Cortex, Leipzig, Germany) will be used to measure oxygen uptake (VO2). VO2max (maximum oxygen uptake) will be considered the highest oxygen uptake during any 15 s of exercise.

19. Sleep quality assessment

    Time frame: 3 days before each condition and during testings.

    Sleep (hours of total sleep and sleep stages) will be monitored using a Garmin wrist-worn watch (Vivo fit 4, UK).

20. Physical activity assessment

    Time frame: 3 days before each condition and during testings.

    Physical activity (steps per day) will be monitored using a Garmin wrist-worn watch (Vivo fit 4, UK).

21. Biochemical urine analysis

    Time frame: 2 times during 1 condition (total 6 times).

    The urine sample will be analyzed in the laboratory using a urine analyzer (PocketChem UA, PU-4010, Arkray, Koji, Konan-cho, Koka-shi, Japan). The analyzer will determine the concentrations of leukocytes.