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Exercise Intensity on Brain & Mental Health in Stress

Not Applicable
Not yet recruiting
Conditions
Adults With Stress-related Symptoms
Healthy Adults
Interventions
Behavioral: Exercise at vigorous intensity
Behavioral: Seated rest
Behavioral: Exercise at moderate intensity
Registration Number
NCT06245538
Lead Sponsor
The Swedish School of Sport and Health Sciences
Brief Summary

This study aims to examine the role of exercise intensity in the acute effects of a single bout of aerobic exercise on neurotrophic factors, biomarkers of stress and inflammation, working memory task-related changes in prefrontal cortex oxygenation in adults with stress-related symptoms, and matched healthy controls.

Detailed Description

This study will include 43 adult (20 - 40 years) participants experiencing stress-related symptoms and 43 healthy controls, matched by age, sex, and fitness. It will be a matched-pair (individuals with stress-related symptoms versus matched healthy controls) randomized-order crossover experimental trial with three experimental conditions separated by a wash-out period of 7 days: 20-min leg cycling exercise at moderate intensity, 20-min leg cycling exercise at vigorous intensity, and 20-min seated rest (passive control condition).

Prior to entering the study, study inclusion/exclusion criteria will be controlled using digital screening. Before the experimental sessions, all participants will complete two introductory study visits. At the first introductory visit, the participant's maximal oxygen uptake (VO2max) will be determined using a fitness test. This information will be used to determine the individual workloads (% of individual VO2max) that the participant will be cycling at during the experimental sessions, as well as for matching the two participant groups for fitness level. At the second introductory visit, participants will complete a familiarization session, in which key methodological aspects of the study will be introduced to participants. Participants' augmentation index, as a measure of arterial stiffness, will also be completed during this visit.

In each of the three experimental sessions, participants will perform a computerized working memory task (n-back task) pre- and post-exercise (or seated rest). During the working memory task, functional near-infrared spectroscopy (fNIRS) will be used to measure task-related changes in prefrontal cortex oxygenation. As such, each participant will complete six fNIRS measurements, two measurements (pre, post) for each of the three experimental sessions (moderate, high, control). Simultaneous with the fNIRS measurements, blood flow velocity in the left and right middle cerebral artery will be assessed during the n-back tasks using Transcranial Doppler ultrasound. At each experimental session, blood will also be sampled from the antecubital vein at seven time points: pre and post the first n-back task, pre and post the cycling exercise (or seated rest), pre and post the second n-back task, and post the final 10-min seated rest. Whole blood samples will be assessed for blood gases, acid-base status, electrolytes, hematocrit level, platelet count, and glucose. The separated blood plasma and serum samples will be used for measurements of neurotrophic factors, lactate, biomarkers of stress and inflammation, and factors involved in blood glucose control. Blood samples will also be used for targeted DNA screening for alleles of the BDNF.

Additionally, the participant's current mood, mental and physical fatigue, heart rate variability (HRV) and blood pressure will be assessed during four 10-min seated rest periods: pre and post n-back, and pre and post cycling exercise (or seated rest). Prior to each experimental study session, participants will have assessments of sleep quality the night before, current health status, physical activity level during the week prior to the test day, sleepiness level the last 10 min, and current mood. Participant's sleep quality and heart rate variability during the night before and after each experimental session will also be assessed.

Recruitment & Eligibility

Status
NOT_YET_RECRUITING
Sex
All
Target Recruitment
86
Inclusion Criteria

For participants both with and without stress-related symptoms:

  • Age: 20-40 years
  • Absence of contraindications to physical exercise
  • Do not participate in any other study

For participants with stress-related symptoms:

• Total score on the self-assessment scale 4-factor Shirom-Melamed Burnout Measure-19 greater than or equal to 2.95 but lower than 4.00

For healthy controls:

• Total score on the self-assessment scale 4-factor SMBM-19 lower than or equal to 2.21

Exclusion Criteria

For participants both with and without stress-related symptoms:

  • Medical contraindication to catheterization of the antecubital vein and blood sampling
  • Dementia
  • Alcohol abuse
  • Smoking
  • Chronic medication that is considered to affect study outcomes
  • Chronic disease/syndrome such as migraine, fibromyalgia, chronic fatigue syndrome, bipolar syndrome, high blood pressure, cardiovascular disease, chronic obstructive pulmonary disease (COPD) or other lung disease
  • Post-COVID
  • Other somatic diseases, disorders, or injuries that may affect the physical ability during physical exercise

Exclusively for healthy controls:

• Depression (HAD depression score < 8) and anxiety (HAD anxiety score < 8)

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Exercise at vigorous intensityExercise at vigorous intensityParticipants will perform a 20-min leg cycling exercise on a cycle ergometer at vigorous intensity (80% of VO2max)
Seated restSeated restParticipants will be resting while seated on a comfortable chair for 20 minutes
Exercise at moderate intensityExercise at moderate intensityParticipants will perform a 20-min leg cycling exercise on a cycle ergometer at moderate intensity (60% of VO2max)
Primary Outcome Measures
NameTimeMethod
Changes in cerebral blood flow in prefrontal cortexfrom before to after 20 minutes of exercise or seated rest

working memory task-related changes in prefrontal cortex oxygenation measured using functional near-infrared spectroscopy

Secondary Outcome Measures
NameTimeMethod
DNA allele of brain-derived neurotrophic factorAt one time point at baseline

in blood sample taken before intervention from the forearm antecubital vein

CortisolAt three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

biomarker of stress; in blood sample taken from the forearm antecubital vein

Mental fatigueAt two time points before and two time points after 20 minutes of exercise or seated rest (In total over 2 hours)

measured using Visual Analogue Scale (VAS-F); scoring scale: a line with 100 mm in length with scores falling between 0 mm (extremely alert) and 100 mm (extremely tired)

Sleep qualityOver the night before and the night after each experimental session (In total over 36 hours)

measured using a Single-Item Sleep Quality Scale; scoring scale is from 0 (terrible) to 10 (excellent)

Heart rate variabilityOver the night before and the night after each experimental session (In total over 36 hours)

as an additional indicator of stress-related symptoms; measured with heart rate sensor and monitor

Brain-derived neurotrophic factorAt three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

pro and mature BDNF in blood sample taken from the forearm antecubital vein; concentrations measured in blood plasma and serum

EpinephrineAt three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

biomarker of stress; in blood sample taken from the forearm antecubital vein

NorepinephrineAt three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

biomarker of stress; in blood sample taken from the forearm antecubital vein

MoodAt two time points before and two time points after 20 minutes of exercise or seated rest (In total over 2 hours)

measured with a short version of Positive and Negative Affect Schedule (PANAS-SF) that include 5 positive and 5 negative affect states; the scoring scale is from 1 (very slightly or not at all) to 5 (extremely)

Augmentation indexAt a single time point at baseline

as a measure of arterial stiffness and indicator of cardiovascular health

Working memory performanceAt one time point before and one time point after 20 minutes of exercise or seated rest (In total over 1 hour)

computerized working memory task (n-back: 1-, 2- and 3-back)

Physical fatigueAt two time points before and two time points after 20 minutes of exercise or seated rest (In total over 2 hours)

measured using Borg Rating of Perceived Exertion scale; scoring scale: from 6 (no exertion) to 20 (maximal exertion)

Interleukin 6 (IL-6)At three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

as a measure of systemic inflammation; in blood sample taken from the forearm antecubital vein

Tumor necrosis factor alpha (TNF-α)At three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

as a measure of systemic inflammation; in blood sample taken from the forearm antecubital vein

Platelet countAt three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

in blood sample taken from the forearm antecubital vein

C-reactive protein (CRP)At three time points before and four time points after 20 minutes of exercise or seated rest (In total over 2 hours)

as a measure of systemic inflammation; in blood sample taken from the forearm antecubital vein

SleepinessAt single time point before 20 minutes of exercise or seated rest

measured using Karolinska Sleepiness Scale; scoring scale is from 1 (extremely alert) to 9 (extremely sleepy)

Trial Locations

Locations (1)

The Swedish School of Sport and Health Sciences

🇸🇪

Stockholm, Sweden

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