Exercise Induced Plasma Volume Expansion Lowers Cardiovascular Strain

April 4, 2023 updated by: California Baptist University

Exercise Induced Plasma Volume Expansion Lowers Cardiovascular Strain and Improves Cycling Time-trial Performance in Acute Normobaric Hypoxia

The goal of this observational study was to better understand the impact of increased plasma volume on later exercise in hypoxia. Investigators examined young, healthy, males who regularly participated in aerobic exercise.

Investigators first measured participant's response to exercise in hypoxia (simulated ~7,500 feet above sea level). The investigators then had participants either 1) undergo 1 bout of high intensity interval exercise or 2) undergo 1 bout of moderate, continuous exercise.

48 hours after the exercise, participants were again examined in hypoxia.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

A crossover design was utilized to assess the effects of exercise-induced plasma volume expansion on cycling performance in hypoxia. All participants completed a high intensity (HI) bout and control (CON) intervention in a counterbalanced order. The HI bout consisted of 8x4min cycling bouts at 85% of VO2peak with 4 min rest between intervals. CON consisted of cycling at 50% VO2peak. Two 15 km, self-paced cycling time trials (TT) were performed before and after each training intervention. The first TT occurred 5 days before the training intervention (HI or CON) and the second TT occurred 48 hours post intervention. Interventions were separated by 14 days to ensure sufficient washout of any training effect as data have suggested retention of expanded plasma volume may last for 7-14 days. During washout, participants were instructed to continue their normal exercise routine.

The investigators hypothesized that a single HI session would increase plasma volume and attenuate cardiovascular strain during exercise in hypoxia, as evidenced by reductions in HR and elevations in SV and Q. Furthermore, the investigators hypothesized that these changes would contribute to a reduced time-to-completion in a 15 km, self-paced cycling TT.

Study Type

Interventional

Enrollment (Actual)

8

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Riverside, California, United States, 92504-3206
        • California Baptist University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 38 years (Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Males age 18-38
  • Exercise at least 3 times/week for at least 30 minutes/day for the past 3 months.

Exclusion Criteria:

  • Frequent hot bath or sauna users
  • Resided at altitude greater than 2,500 meters for >14 days.
  • Cardiovascular or metabolic disease

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: High Intensity Exercise
Vigorous cycling
Procedure: High Intensity Intervals
8x4 min cycling bouts at 85% of VO2peak
Active Comparator: Continuous Moderate Exercise
Leisurely cycling
Procedure: Moderate Exercise
81 minutes of cycling at 50% VO2peak

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hemoglobin Concentration
Time Frame: through study completion, an average of 4 weeks
measured through spectroscopy
through study completion, an average of 4 weeks
Hematocrit Concentration
Time Frame: through study completion, an average of 4 weeks
measured through hematocrit reader
through study completion, an average of 4 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Time Trial Time
Time Frame: through study completion, an average of 4 weeks
Time to complete 15 km
through study completion, an average of 4 weeks
Cardiac Output
Time Frame: through study completion, an average of 4 weeks
measured via impedance cardiography
through study completion, an average of 4 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

California Baptist University

Collaborators

High Point University
United States Army Research Institute of Environmental Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 15, 2019

Primary Completion (Actual)

December 15, 2019

Study Completion (Actual)

December 8, 2022

Study Registration Dates

First Submitted

February 28, 2023

First Submitted That Met QC Criteria

April 4, 2023

First Posted (Actual)

April 6, 2023

Study Record Updates

Last Update Posted (Actual)

April 6, 2023

Last Update Submitted That Met QC Criteria

April 4, 2023

Last Verified

April 1, 2023

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • Plasma Volume and Hypoxia

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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