Physiological Responses to High-Intensity Exercise
Conditions
Keywords
Q-collar, Jugular vein compression, Functional near-infrared spectroscopy, Prefrontal cortex oxygenation, Cognitive performance, Cycling performance
Brief summary
This study examined the effects of wearing the Q-Collar during high-intensity cycling exercise. Eleven recreationally trained male participants completed two 5-kilometer cycling time trials: one while wearing the Q-Collar and one without the Q-Collar. During and after each trial, researchers measured cardiovascular responses, brain oxygenation, blood lactate, perceived exertion, cognitive performance, and cycling performance. The purpose of the study was to determine whether wearing the Q-Collar affects physiological responses, cognitive function, or performance during high-intensity exercise.
Detailed description
This randomized crossover study examined the effects of Q-Collar use during high-intensity cycling exercise. Recreationally trained male participants completed two laboratory testing sessions in randomized order: a 5-kilometer cycling time trial while wearing the Q-Collar and a 5-kilometer cycling time trial without the Q-Collar. The Q-Collar applies mild bilateral compression to the internal jugular veins and is designed to increase cerebral blood volume. During each trial, cardiovascular responses were assessed continuously, while prefrontal cortex oxygenation was measured using functional near-infrared spectroscopy. Blood lactate and ratings of perceived exertion were assessed during exercise, and cognitive performance was evaluated before and after each cycling trial. Cycling performance was also recorded. The study was designed to determine whether wearing the Q-Collar alters physiological responses to high-intensity exercise, particularly cardiovascular function and prefrontal cortex oxygenation, and whether these responses are accompanied by changes in cognitive or cycling performance. The crossover design allowed each participant to complete both conditions and therefore serve as his own control.
Interventions
DEVICEQ-Collar™
The Q-Collar™ is a wearable neck device that applies mild bilateral compression to the internal jugular veins. Participants wore the Q-Collar during a 5-kilometer cycling time trial. The device was individually fitted according to manufacturer guidelines and remained in place throughout the exercise trial.
Sponsors
University of Northern Iowa
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Intervention model description
Participants completed two 5-kilometer cycling time trials in randomized, counterbalanced order: one while wearing the Q-Collar and one without the Q-Collar. Each participant served as his own control, with at least 72 hours between conditions.
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Male participants * 18-35 years old * Recreationally trained * Provided written informed consent * Achieved a maximal oxygen consumption (VO₂max) classified as "good" or "excellent" during cardiopulmonary exercise testing
Exclusion criteria
* Failure to meet the required "good" or "excellent" VO₂max classification during cardiopulmonary exercise testing * Outside age range
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Prefrontal Cortex Oxygenation | All throughout each 5-kilometer cycling time trial, approximately 10 minutes | Changes in prefrontal cortex oxygenated hemoglobin were continuously measured using functional near-infrared spectroscopy during 5-kilometer cycling time trials performed with and without the Q-Collar. Data were evaluated across kilometer time points. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Cycling Time-Trial Performance | At completion of each 5-kilometer cycling time trial, approximately 30 seconds | Time in seconds required to complete the 5-kilometer cycling time trial was recorded for the Q-Collar and control conditions. |
| Choice Reaction Time | At baseline, 5 minutes into exercise, immediately post-exercise, and 10 minutes post-exercise during each experimental visit, approximately 2 minutes at each time point | Choice reaction time was assessed using a computerized Stroop task. Reaction time and response accuracy were evaluated across the Q-Collar and control conditions. |
| Heart Rate | During each 5-kilometer cycling time trial, approximately 10 minutes | Heart rate was continuously assessed using cardiac impedance and compared across the Q-Collar and control conditions. |
| Stroke Volume | During each 5-kilometer cycling time trial, approximately 10 minutes | Stroke volume was continuously assessed using cardiac impedance and compared across the Q-Collar and control conditions. |
| Cardiac Output | During each 5-kilometer cycling time trial, approximately 10 minutes | Cardiac output was continuously assessed using cardiac impedance and compared across the Q-Collar and control conditions. |
| Blood Lactate | Immediately following each 5-kilometer cycling time trial, approximately 1 minute | Blood lactate concentration (mmol/L) was measured from an earlobe capillary blood sample immediately following each cycling time trial. |
| Rating of Perceived Exertion | Immediately following each 5-kilometer cycling time trial, approximately 30 seconds | Rating of perceived exertion was assessed using the Borg 6-20 scale immediately following each 5-kilometer cycling time trial. |
Countries
United States
Outcome results
None listed