Effects of Railway Vibration on Sleep and Disease

Sleep Disturbance Clinical Trial

— BioVib  

Official title:

Effects of Railway Vibration on Sleep and Disease

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06260254
• Other study ID #: 244826201
• Status: Recruiting
• Phase: N/A
• Start date: February 5, 2024
• Est. completion date: December 31, 2024

Study information

• Verified date: February 2024
• Source: Göteborg University
• Contact: Michael G Smith, PhD
• Phone: +46-031-786-2843
• Email: michael.smith[@]amm.gu.se
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study will investigate the biological mechanisms linking sleep disruption by vibration and noise, and the development of cardiometabolic disease. In a laboratory sleep study, the investigators will play railway vibration of different levels during the night. The investigators will also measure objective sleep quality and quantity, cognitive performance across multiple domains, self-reported sleep and wellbeing outcomes, and blood samples. Blood samples will be analyzed to identify metabolic changes and indicators of diabetes risk in different nights. Identifying biomarkers that are impacted by sleep fragmentation will establish the currently unclear pathways by which railway vibration exposure at night can lead to the development of diseases in the long term, especially metabolic disorders including diabetes.

Description:

The experimental sleep study has the overarching goal of deepening understanding of sleep disruption by railway vibration and noise and changes in cardiometabolic and cognitive function. To this end, the study will address the following study aim:

Aim 1: Determine the biological and neurobehavioral consequences of sleep disruption by railway vibration. The investigators will measure the sleep of healthy volunteers, and each morning will obtain blood samples for metabolomics metabolic function analysis and administer a neurocognitive test battery. The investigators will compare effects on sleep, metabolomics, metabolic function and cognitive function between quiet nights and nights with railway traffic vibration and noise. Dose-response relationships will be determined by comparing nights with different levels of vibration.

This study will take place in the sound environment laboratory (SEL) at the University of Gothenburg Department of Occupational and Environmental Medicine. The SEL is a high fidelity research laboratory equipped to simulate a typical apartment, including three individually light-, sound- and vibration-isolated private bedrooms. Ceiling mounted speakers in each room and electrodynamic transducers mounted to the underside of each bed allow the investigators to create a realistic acoustic environment by transmitting sound and vibration exposures from the control room to each bedroom individually. The investigators have shown previously that results from this lab with high ecological validity are comparable with results from the field.

This study has a prospective within-subjects cross-over design. Participants (total N=24) will each spend five consecutive nights in the SEL, with a sleep opportunity between 23:00-07:00. Daytime sleep will be prohibited, confirmed with measures of daytime activity via wrist actigraphy monitors worn continuously throughout the study. Three subjects will take part concurrently, in separate bedrooms. The first night is a habituation period to the study protocol and for familiarization with the test procedures. The second night will be a quiet condition without noise or vibration, to determine normal baseline sleep, cardiometabolic profile, and cognitive performance. Study nights 3-5 are the vibration nights and will be randomly assigned across participants using a Latin square design to avoid first-order carryover effects. In these vibration nights, vibration and noise from railway freight will be played into the bedrooms to determine the effects of vibration and noise on sleep, cardiometabolic function and cognitive performance. Thirty six trains will occur each night, randomly distributed across the 8-hour sleep period.

For railway vibration the investigators will use synthesized signals based on measured data, used in previous laboratory studies. It is necessary to use synthesized vibration, rather than recorded signals, so that the investigators can accurately adjust the acoustical character of the exposure as needed. Railway vibration will be accompanied by high fidelity recordings of railway freight noise. This is to maximize ecological validity of the exposures since vibration rarely occurs without noise, and to mask any mechanical sounds from the vibration transducers.

Vibration and noise exposures will reflect realistic railway freight traffic noise levels that occur in dwellings alongside railway lines in Sweden. The maximum Wm-weighted vibration amplitudes in the three vibration nights will be 0.5 mm/s, 0.7 mm/s and 0.9 mm/s respectively. Maximum sound pressure levels of individual train passages will not exceed 49.8 dB LAF,max. Trains will vary from 11.5 s to 56.9 s in duration. All vibration amplitudes will be calibrated on the mattress of the bed, under a 75 kg reference weight to simulate the bed being occupied. All sound pressure levels will be calibrated to 10 cm above the pillow in each bedroom prior to the study, so that these levels accurately reflect the noise exposure of the subjects during sleep.

Each night the investigators will record physiologic sleep with polysomnography (PSG) and cardiac activity with electrocardiography (ECG). Each study morning, subjects will provide a 2ml blood sample and answer questionnaires and will depart the SEL to follow their normal daytime routine. They will return to the SEL at 20:00 each evening to prepare for sleep measurements. Caffeine will be prohibited after 15:00 and alcohol will be prohibited at all times. Because extreme and/or variable dietary behavior can affect the metabolome/lipoprotein profile, participants will be given guidance that they should eat a similar evening meal on each day of the laboratory study, confirmed with a food diary. The actual meal itself can be different for different study participants, because the study has a within-subjects design.

Sleep will be recorded with ambulatory polysomnography (PSG) and cardiac activity with electrocardiography (ECG) and finger pulse photoplethysmogram. Data are recorded offline onto the sleep recorder, and will be downloaded and checked every study morning to ensure data quality. In addition to traditional sleep analysis, raw PSG data will be used to calculate the Odds Ratio Project, a novel metric of sleep depth and stability.

Each study morning subjects will provide a 2 ml blood sample for plasma metabolomics analysis. To ensure reliable data, blood samples will be taken at the same time every day to mitigate circadian effects, before eating or drinking anything except water, and each sample will be handled in the same way i.e. centrifuged, aliquoted and stored in -80C freezers. Subjects will eat the same food each study evening to mitigate within-subject dietary effects on the blood metabolome. Furthermore, a 2-hour oral glucose tolerance test (OGTT) will be performed in the mornings after the quiet control night (i.e. after study night 2) and after the third vibration exposure night (i.e. after study night 5). The investigators will measure response to a 75g glucose bolus at timepoints 10, 20, 30, 60, 90 and 120 minutes after the glucose administration.

Each evening, subjects will complete a computerized cognitive test battery taking approximately 20 minutes, that includes 10 tests across a range of cognitive domains (motor praxis, visual object learning, fractal 2-back, abstract matching, line orientation, emotion recognition, matrix reasoning, digit symbol substitution, balloon analog risk, psychomotor vigilance). Cognition data will be analyzed to determine key measures of cognitive speed and accuracy, adjusting for practice effects and the difficulty of the stimulus set.

Subjects will complete a battery of one-time validated questionnaires to measure their general health (SF-36), chronotype, noise sensitivity, habitual sleep quality, environmental sensitivity, and annoyance and sleep disturbance by noise. Subjects will also answer a questionnaire each study evening and morning, involving questions on sleepiness (Karolinska Sleepiness Scale), auditory fatigue, sleep disturbance by noise, and validated sleep and disturbance questions.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 24
• Est. completion date: December 31, 2024
• Est. primary completion date: June 30, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 30 Years

Eligibility

Inclusion Criteria:

1) live in or around the city of Gothenburg area (Sweden)

Exclusion Criteria:

1. aged <18 or >30 years;

2. habitual sleep and wake timings more than ±1 hour different from the study sleep times (i.e. habitual sleep time should be 22:00-00:00 and habitual wake time should be 06:00-08:00);

3. BMI>25 kg/m2;

4. regular sleep medication use (prescribed or "over-the-counter");

5. poor hearing acuity (measured during screening via pure tone audiometry);

6. diagnosed with sleep disorders;

7. diagnosed with diabetes

8. indications of sleep apnea on the STOP-BANG questionnaire;

9. shift work;

10. smoking, vaping, snus, or other nicotine use;

11. pregnant or breastfeeding

Related Conditions & MeSH terms

• Cognitive Change
• Dyssomnias
• Glucose Metabolism Disorders
• Glucose Metabolism Disorders (Including Diabetes Mellitus)
• Metabolic Diseases
• Metabolic Disturbance
• Noise Exposure
• Parasomnias
• Sleep Disturbance
• Sleep Hygiene
• Vibration; Exposure

Intervention

Radiation:
• Railway noise
Low level railway noise, not exceeding 50 dB LAF,max. Thirty six single railway noise events.
• Low level railway vibration
36 single railway noise events at 0.5 mm/s, varying from 11.5 s to 56.9 s in duration. Vibration always occurs concurrently with the noise exposure.
• Intermediate level railway vibration
36 single railway noise events at 0.7 mm/s, varying from 11.5 s to 56.9 s in duration. Vibration always occurs concurrently with the noise exposure.
• High level railway vibration
36 single railway noise events at 0.9 mm/s, varying from 11.5 s to 56.9 s in duration. Vibration always occurs concurrently with the noise exposure.

Locations

Country	Name	City	State
Sweden	University of Gothenburg	Gothenburg	Västra Götaland

Sponsors (3)

Lead Sponsor	Collaborator
Göteborg University	University of Manitoba, University of Pennsylvania

Country where clinical trial is conducted

Sweden, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Fasting insulin resistance in the morning immediately after the Control night	Calculated using the Homeostatic model of insulin resistance (HOMA-IR)	One night
Primary	Fasting insulin resistance in the morning immediately after the low vibration night	Calculated using the Homeostatic model of insulin resistance (HOMA-IR)	One night
Primary	Fasting insulin resistance in the morning immediately after the intermediate vibration night	Calculated using the Homeostatic model of insulin resistance (HOMA-IR)	One night
Primary	Fasting insulin resistance in the morning immediately after the high vibration night	Calculated using the Homeostatic model of insulin resistance (HOMA-IR)	One night
Primary	Total sleep time during the Control night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total sleep time during the low vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total sleep time during the intermediate vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total sleep time during the high vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N1 sleep during the Control night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N2 sleep during the Control night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N3 sleep during the Control night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of rapid eye movement (REM) sleep during the Control night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N1 sleep during the low vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N2 sleep during the low vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N3 sleep during the low vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of rapid eye movement (REM) sleep during the low vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N1 sleep during the intermediate vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N2 sleep during the intermediate vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N3 sleep during the intermediate vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of rapid eye movement (REM) sleep during the intermediate vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N1 sleep during the high vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N2 sleep during the high vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of N3 sleep during the high vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Total amount of rapid eye movement (REM) sleep during the high vibration night	Measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines	One night
Primary	Wakefulness after sleep onset (WASO) during the Control night	Total number of minutes awake during the night after the first appearance of sleep of any stage. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Wakefulness after sleep onset (WASO) during the low vibration night	Total number of minutes awake during the night after the first appearance of sleep of any stage. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Wakefulness after sleep onset (WASO) during the intermediate night	Total number of minutes awake during the night after the first appearance of sleep of any stage. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Wakefulness after sleep onset (WASO) during the high vibration night	Total number of minutes awake during the night after the first appearance of sleep of any stage. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Number of awakenings during the Control night	Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Number of awakenings during exposure to low vibration	Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Number of awakenings during exposure to intermediate vibration	Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Number of awakenings during exposure to high vibration	Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep onset latency (SOL) during the Control Night	Defined as the time from lights out to the first epoch of sleep. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep onset latency (SOL) during the low vibration night	Defined as the time from lights out to the first epoch of sleep. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep onset latency (SOL) during the intermediate vibration night	Defined as the time from lights out to the first epoch of sleep. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep onset latency (SOL) during the high vibration night	Defined as the time from lights out to the first epoch of sleep. Measured via Polysomnography /EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep efficiency during the Control night	Defined as the percentage of time in bed spent in a non-wake sleep stage, measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep efficiency during the low vibration night	Defined as the percentage of time in bed spent in a non-wake sleep stage, measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep efficiency during the intermediate vibration night	Defined as the percentage of time in bed spent in a non-wake sleep stage, measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	S Sleep efficiency during the high vibration night	Defined as the percentage of time in bed spent in a non-wake sleep stage, measured via polysomnography/EEG, scored according to American Academy of Sleep Medicine guidelines.	One night
Primary	Sleep depth assessed using the odds ratio product (ORP) during the Control night	Average ORP over the full night, from 0 (never occurs during wake) to 2.5 (only occurs during wake). Derived via polysomnography/EEG measurements.	One night
Primary	Sleep depth assessed using the odds ratio product (ORP) during the low vibration night	Average ORP over the full night, from 0 (never occurs during wake) to 2.5 (only occurs during wake). Derived via polysomnography/EEG measurements.	One night
Primary	Sleep depth assessed using the odds ratio product (ORP) during the intermediate vibration night	Average ORP over the full night, from 0 (never occurs during wake) to 2.5 (only occurs during wake). Derived via polysomnography/EEG measurements.	One night
Primary	Sleep depth assessed using the odds ratio product (ORP) during the high vibration night	Average ORP over the full night, from 0 (never occurs during wake) to 2.5 (only occurs during wake). Derived via polysomnography/EEG measurements.	One night
Primary	Maximal change of odds ratio product (ORP) during exposure to railway vibration events	Measure of acute sleep disruption by noise, calculated as the difference between the ORP in the 30s prior to noise onset and the maximum ORP during railway vibration. Averaged over 36 vibration events during the night.	One night
Primary	Area under the curve of odds ratio product (ORP) during exposure to railway vibration events, calculated using the trapezoid rule	Measure of acute sleep disruption by noise, calculated as the difference between the ORP in the 30s prior to noise onset and the maximum ORP during railway vibration. Averaged over 36 vibration events during the night.	One night
Primary	N-acetylglucosamine/galactosamine (GlycA) concentration after the Control night	Determined from NMR analysis of blood plasma	One night
Primary	N-acetylglucosamine/galactosamine (GlycA) concentration after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	N-acetylglucosamine/galactosamine (GlycA) concentration after exposure to intermediate vibration	Determined from NMR analysis of blood plasma	One night
Primary	N-acetylglucosamine/galactosamine (GlycA) concentration after exposure to high vibration	Determined from NMR analysis of blood plasma	One night
Primary	Sialic acid (GlycB) concentration after the Control night	Determined from NMR analysis of blood plasma	One night
Primary	Sialic acid (GlycB) concentration after exposure to low vibration	Determined from NMR analysis of blood plasma	One night
Primary	Sialic acid (GlycB) concentration after exposure to intermediate vibration	Determined from NMR analysis of blood plasma	One night
Primary	Sialic acid (GlycB) concentration after exposure to high vibration	Determined from NMR analysis of blood plasma	One night
Primary	Supramolecular phospholipid composite (SPC) concentration after the Control night	Determined from NMR analysis of blood plasma	One night
Primary	Supramolecular phospholipid composite (SPC) concentration after exposure to low vibration	Determined from NMR analysis of blood plasma	One night
Primary	Supramolecular phospholipid composite (SPC) concentration after exposure to intermediate vibration	Determined from NMR analysis of blood plasma	One night
Primary	Supramolecular phospholipid composite (SPC) concentration after exposure to high vibration	Determined from NMR analysis of blood plasma	One night
Primary	Ethanol concentration (mmol/L) after the Control night	Determined from NMR analysis of blood plasma	One night
Primary	Ethanol concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Ethanol concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Ethanol concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Trimethylamine-N-oxide concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Trimethylamine-N-oxide concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Trimethylamine-N-oxide concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Trimethylamine-N-oxide concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Aminobutyric acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One
Primary	2-Aminobutyric acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One
Primary	2-Aminobutyric acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One
Primary	2-Aminobutyric acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One
Primary	Alanine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Alanine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Alanine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Alanine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Asparagine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Asparagine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Asparagine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Asparagine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Creatine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatinine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Creatinine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatinine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Creatinine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glutamine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Glycine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Histidine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Histidine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Histidine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Histidine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Isoleucine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Isoleucine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Isoleucine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Isoleucine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Leucine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Leucine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Leucine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Leucine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lysine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Lysine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lysine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lysine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Methionine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Methionine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Methionine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Methionine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	N,N-Dimethylglycine concentration (mmol/L) after Control night	Determined from NMR analysis of blood plasma	One night
Primary	N,N-Dimethylglycine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	N,N-Dimethylglycine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	N,N-Dimethylglycine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Ornithine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Ornithine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Ornithine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Ornithine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Phenylalanine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Phenylalanine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Phenylalanine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Phenylalanine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Proline concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Proline concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Proline concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Proline concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Sarcosine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Sarcosine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Sarcosine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Sarcosine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Threonine concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Threonine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Threonine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Threonine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Tyrosine concentration (mmol/L) after exposure toControl night	Determined from NMR analysis of blood plasma	One night
Primary	Tyrosine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Tyrosine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Tyrosine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Valine concentration (mmol/L) after Control night	Determined from NMR analysis of blood plasma	One night
Primary	Valine concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Valine concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Valine concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Hydroxybutyric acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	2-Hydroxybutyric acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Hydroxybutyric acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Hydroxybutyric acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Acetic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Citric acid concentration (mmol/L) after Control night	Determined from NMR analysis of blood plasma	One night
Primary	Citric acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Citric acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Citric acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Formic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Formic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Formic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Formic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lactic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Lactic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lactic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Lactic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Succinic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Succinic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Succinic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Succinic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Choline concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Choline concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Choline concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Choline concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Oxoglutaric acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	2-Oxoglutaric acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Oxoglutaric acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	2-Oxoglutaric acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	3-Hydroxybutyric acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	3-Hydroxybutyric acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	3-Hydroxybutyric acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	3-Hydroxybutyric acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetoacetic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Acetoacetic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetoacetic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetoacetic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetone concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Acetone concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetone concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Acetone concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Pyruvic acid concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Pyruvic acid concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Pyruvic acid concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Pyruvic acid concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	D-Galactose concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	D-Galactose concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	D-Galactose concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	D-Galactose concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glucose concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Glucose concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glucose concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glucose concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycerol concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Glycerol concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycerol concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Glycerol concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Dimethylsulfone concentration (mmol/L) after exposure to Control night	Determined from NMR analysis of blood plasma	One night
Primary	Dimethylsulfone concentration (mmol/L) after exposure to low vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Dimethylsulfone concentration (mmol/L) after exposure to intermediate vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Dimethylsulfone concentration (mmol/L) after exposure to high vibration night	Determined from NMR analysis of blood plasma	One night
Primary	Response to an oral glucose bolus, calculated as area under curve for glucose, in the morning after the control night	Area under the curve (AUC) calculated using the trapezoidal rule, from glucose samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus.	One night
Primary	Response to an oral glucose bolus, calculated as area under curve for glucose, in the morning after the low vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from glucose samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus.	One night
Primary	Response to an oral glucose bolus, calculated as area under curve for glucose, in the morning after the intermediate vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from glucose samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus.	One night
Primary	Response to an oral glucose bolus, calculated as area under curve for glucose, in the morning after the high vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from glucose samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus.	One night
Primary	Response to an oral glucose load calculated as area under curve for insulin, in the morning after the low vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus	One night
Primary	Response to an oral glucose load calculated as area under curve for insulin, in the morning after the intermediate vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus	One night
Primary	Response to an oral glucose load calculated as area under curve for insulin, in the morning after the high vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20, 30, 60, 90 and 120 minutes after the glucose bolus	One night
Primary	Early response to an oral glucose load calculated as area under curve for insulin, in the morning after the control night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20 and 30 minutes after the glucose bolus	One night
Primary	Early response to an oral glucose load calculated as area under curve for insulin, in the morning after the low vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20 and 30 minutes after the glucose bolus	One night
Primary	Early response to an oral glucose load calculated as area under curve for insulin, in the morning after the intermediate vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20 and 30 minutes after the glucose bolus	One night
Primary	Early response to an oral glucose load calculated as area under curve for insulin, in the morning after the high vibration night	Area under the curve (AUC) calculated using the trapezoidal rule, from insulin samples collected 10, 20 and 30 minutes after the glucose bolus	One night
Primary	Glucose tolerance in the morning after exposure to low vibration, assessed as glucose concentration 120 minutes after a glucose bolus	Glucose concentrations determined from plasma samples with the Hexokinase/G-6-PDH method	One night
Primary	Glucose tolerance in the morning after exposure to intermediate vibration, assessed as glucose concentration 120 minutes after a glucose bolus	Glucose concentrations determined from plasma samples with the Hexokinase/G-6-PDH method	One night
Primary	Glucose tolerance in the morning after exposure to high vibration, assessed as glucose concentration 120 minutes after a glucose bolus	Glucose concentrations determined from plasma samples with the Hexokinase/G-6-PDH method	One night
Primary	Glucose tolerance in the morning after Control night, assessed as glucose concentration 120 minutes after a glucose bolus	Glucose concentrations determined from plasma samples with the Hexokinase/G-6-PDH method	One night
Primary	Stumvoll Insulin sensitivity Index in the morning after control	.226 - 0.0032 × BMI - 0.0000645 × I120 - 0.00375 × G90, where I120 and G90 represent insulin concentration 120 minutes after the glucose bolus, and glucose concentration 90 minutes after the glucose bolus, respectively.	One night
Primary	Stumvoll Insulin sensitivity Index in the morning after exposure to low vibration	.226 - 0.0032 × BMI - 0.0000645 × I120 - 0.00375 × G90, where I120 and G90 represent insulin concentration 120 minutes after the glucose bolus, and glucose concentration 90 minutes after the glucose bolus, respectively.	One night
Primary	Stumvoll Insulin sensitivity Index in the morning after exposure to intermediate vibration	.226 - 0.0032 × BMI - 0.0000645 × I120 - 0.00375 × G90, where I120 and G90 represent insulin concentration 120 minutes after the glucose bolus, and glucose concentration 90 minutes after the glucose bolus, respectively.	One night
Primary	Stumvoll Insulin sensitivity Index in the morning after exposure to high vibration	.226 - 0.0032 × BMI - 0.0000645 × I120 - 0.00375 × G90, where I120 and G90 represent insulin concentration 120 minutes after the glucose bolus, and glucose concentration 90 minutes after the glucose bolus, respectively.	One night
Primary	Matsuda insulin sensitivity index in the morning after control exposure	Calculated as 10,000/square root of [fasting glucose × fasting insulin] × [mean glucose × mean insulin during oral glucose tolerance test])	One night
Primary	Matsuda insulin sensitivity index in the morning after exposure to low vibration	Calculated as 10,000/square root of [fasting glucose × fasting insulin] × [mean glucose × mean insulin during oral glucose tolerance test])	One night
Primary	Matsuda insulin sensitivity index in the morning after exposure to intermediate vibration	Calculated as 10,000/square root of [fasting glucose × fasting insulin] × [mean glucose × mean insulin during oral glucose tolerance test])	One night
Primary	Matsuda insulin sensitivity index in the morning after exposure to high vibration	Calculated as 10,000/square root of [fasting glucose × fasting insulin] × [mean glucose × mean insulin during oral glucose tolerance test])	One night
Secondary	Evening subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to control	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Evening subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to low vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Evening subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to intermediate vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Evening subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to high vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Morning subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to control	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Morning subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to low vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Morning subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to intermediate vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Morning subjective sleepiness, assessed using the Karolinska Sleepiness Scale after exposure to high vibration	The scale is a 9-level verbal scale from 1 - "Extremely alert" (best outcome) to 9 - "Very sleepy. great effort to keep alert, fighting sleep" (worst outcome)	One night
Secondary	Self-reported sleep disturbance by vibration after control exposure	Assessed on a 0-10 numerical scale, from "Not at all" to "Extremely"	One night
Secondary	Self-reported sleep disturbance by vibration after exposure to low vibration	Assessed on a 0-10 numerical scale, from "Not at all" to "Extremely"	One night
Secondary	Self-reported sleep disturbance by vibration after exposure to intermediate vibration	Assessed on a 0-10 numerical scale, from "Not at all" to "Extremely"	One night
Secondary	Self-reported sleep disturbance by vibration after exposure to high vibration	Assessed on a 0-10 numerical scale, from "Not at all" to "Extremely"	One night
Secondary	Morning positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after control exposure	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to low vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to intermediate vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to high vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after control exposure	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to low vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to intermediate vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Morning negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to high vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to control	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to low vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to intermediate vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening negative affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to high vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to control	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to low vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to intermediate vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Evening positive affect, assessed using the Positive and Negative Affect Schedule (PANAS) after exposure to high vibration	PANAS is a 20-item instrument in which 20 words describing current mood and emotional state are rated on a 5-point Likert scale from "Not at all" to "Extremely". A composite positive affect score is calculated from 10 of these.	One night.
Secondary	Event-related cardiovascular activation in response to control	Change in heart rate (ECG)	One night
Secondary	Event-related cardiovascular activation in response to low vibration	Change in heart rate (ECG)	One night
Secondary	Event-related cardiovascular activation in response to intermediate vibration	Change in heart rate (ECG)	One night
Secondary	Event-related cardiovascular activation in response to high vibration	Change in heart rate (ECG)	One night
Secondary	Evening neurobehavioural speed	Average of one key speed indicator from each of 10 cognitive tests (motor praxis, visual object learning, fractal 2-back, abstract matching, line orientation, emotion recognition, matrix reasoning, digit symbol substitution, balloon analog risk, psychomotor vigilance)	One night
Secondary	Evening neurobehavioural accuracy	Average of one key accuracy indicator from each of 9 cognitive tests (motor praxis, visual object learning, fractal 2-back, abstract matching, line orientation, emotion recognition, matrix reasoning, digit symbol substitution, psychomotor vigilance)	One night