Effects of Partial Sleep Deprivation on Cardiac Output During Cycling

The goal of this clinical trial is to determine if attenuations in cardiac output drive the blunted blood pressure response during cycling exercise following a night of partial sleep deprivation in young healthy adults (%50 females). The secondary outcome is to assess sex differences. The main questions it aims to answer are:

• Do reductions in plasma volume drive reductions in cardiac output and therefore blood pressure during exercise following a night of partial sleep deprivation?
• Do sex differences exist?

Participants will:

• Visit the lab after a night of normal sleep and a night of partial sleep deprivation.
• Keep a daily diary of their sleep and food/beverage intake.
• Perform maximal and submaximal exercise on a cycle ergometer.

Study Overview

• Status: Recruiting
• Conditions: Sleep Deprivation
• Intervention / Treatment: Other: Partial sleep deprivation

Detailed Description

The investigators recently published data showing systolic blood pressure is attenuated during cycling exercise in males but not females following acute partial sleep deprivation, compared to a night of normal sleep, despite no differences in power output. The mechanisms responsible for this sex difference remain unknown. The investigators have pilot data that suggests males have a reduction in cardiac output following acute partial sleep deprivation, but females do not. Therefore, the primary purpose of this study is to assess hemodynamics (blood pressure, stroke volume, and cardiac output) and plasma volume during cycling exercise following a night of normal sleep and partial sleep deprivation in otherwise healthy males and females.

Thirty young healthy adults (50% female) will be recruited to undergo three visits. The first visit will assess maximal oxygen uptake to determine aerobic fitness and metabolic exercise intensity zones. The following two testing visits will be randomized and will be completed after a night of normal sleep or acute partial sleep deprivation (early awakening, 40% normal sleep duration). Sleep will be measured 1-week before each visit subjectively (questionnaire) to determine habitual sleep timing and duration and objectively (wrist actigraphy) the night before each testing visit. Each testing visit will require participants to complete a constant load 60-minute bout of cycling. Before, during, and after the exercise protocol, the investigators will measure hemodynamics and plasma volume. Venous blood samples will be collected via intravenous lines.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Julian Bommarito, MSc; Phone Number: 9052209829; Email: jbomma01@uoguelph.ca

Study Locations

• Canada
  • Ontario
    • Guelph, Ontario, Canada, N1G 2W1
      • Recruiting
      • University of Guelph
      • Contact: Julian Bommarito, MSc; Phone Number: 9052209829; Email: jbomma01@uoguelph.ca
      • Sub-Investigator: Julian Bommarito, MSc

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Free of known cardiovascular or metabolic diseases or sleep disorders
• No history of smoking (within the past 3 months)
• Able to engage in physical activity assessed through the physical activity readiness questionnaire (PAR-Q+)
• No prescription of chronic medications other than oral contraceptives
• Able to abide by sleep protocols for all visits
• Individuals who are not allergic to ultrasound gel
• Individuals who are not pregnant

Exclusion Criteria:

• Individuals diagnosed with cardiovascular or metabolic disease or sleep disorders
• Has a history of smoking (within the past 3 months)
• Not ready to engage in physical activity as assessed by the PAR-Q+
• Individuals prescribed chronic medications other than oral contraceptives
• Unable to abide by sleep protocols for any testing visit
• Allergic to ultrasound gel
• Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Normal sleep; During this arm, participants will be asked to come to the lab for testing after a night of normal sleep. Normal sleep will be defined as participants habitual sleep-wake timing.
Experimental: Partial sleep deprivation; During this arm, participants will be asked to come to the lab for testing after a night of partial sleep deprivation. Participants will be asked to fall asleep at their habitual bedtime but wake up early (~40% of normal sleep duration).	Other: Partial sleep deprivation; Participants will be asked to come to the lab for testing after a night of partial sleep deprivation. Participants will be asked to fall asleep at their habitual bedtime but wake up early (~40% of normal sleep duration).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cardiac output responses to cycling exercise	Cardiac output during exercise after a night of normal sleep and after a night of partial sleep deprivation	Comparison between normal sleep and partial sleep deprivation, ~3 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood pressure responses to cycling exercise	Blood pressure during exercise after a night of normal sleep and after a night of partial sleep deprivation	Comparison between normal sleep and partial sleep deprivation, ~3 weeks
Plasma volume	Plasma volume after a night of normal sleep and after a night of partial sleep deprivation	Comparison between normal sleep and partial sleep deprivation, ~3 weeks

Collaborators and Investigators

• Sponsor: University of Guelph
• Investigators: Principal Investigator: Philip Millar, PhD, University of Guelph; Study Director: Julian Bommarito, MSc, University of Guelph

Study record dates

Study Major Dates

• Study Start (Actual): January 2, 2025
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: November 5, 2024
• First Submitted That Met QC Criteria: November 5, 2024
• First Posted (Actual): November 7, 2024

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: sleep deprivation; cardiac output; plasma volume; exercise blood pressure
• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Mental Disorders; Sleep Wake Disorders; Dyssomnias; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sleep Deprivation
• Other Study ID Numbers: 24-03-017

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: IPD used in the results publication
• IPD Sharing Time Frame: Beginning after publication with no end date

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No