Exercise Frequency During Endurance Training: Cardiorespiratory, Hematological, and Muscle Oxidative Adaptations

NCT05908578 | Completed

• 1 other identifier: REB23-0467
• Study Type: interventional
• Target: 30
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this interventional study is to compare training for different numbers of days each week in healthy, young individuals. The main questions it aims to answer are:

• Does exercising less often improve endurance fitness as much as exercising more often?
• Are endurance fitness improvements caused by improvements in the muscle and blood? Participants will train on a stationary bike for eight weeks. Researchers will measure the participants endurance fitness, as well as muscle and blood characteristics, before and after training to look for improvements from the training protocols. Researchers will compare low-frequency exercise (two times per week) and high-frequency exercise (four times per week) to see if they each improve endurance fitness.

Conditions

Exercise Training

Keywords

Exercise; Muscle, Striated; Blood; Erythrocytes; Cardiorespiratory Fitness

Outcome Measures

Primary Outcomes (1)

• Change from baseline maximal oxygen uptake (VO2max) after 8 weeks of training

  Change in maximal oxygen uptake determined using an incremental exercise test on a cycle ergometer, measured after 8 weeks of training relative to baseline

  8 weeks

Secondary Outcomes (8)

• Change from baseline near-infrared spectroscopy (NIRS)-derived oxidative capacity of the vastus lateralis muscle after 8 weeks of training

  8 weeks

• Change from baseline hemoglobin mass after 8 weeks of training

  8 weeks

• Change from baseline gas exchange threshold after 8 weeks of training

  8 weeks

• Change from baseline respiratory compensation point after 8 weeks of training

  8 weeks

• Change from baseline peak power output after 8 weeks of training

  8 weeks

Study Arms (2)

High-Frequency Training

ACTIVE COMPARATOR

Exercise performed on a stationary bike four times per week. Total weekly exercise volume (the product of intensity, duration, and frequency) will be matched between groups. Intensity will be the same, so the high-frequency group will perform half the duration of exercise in each session compared to the low-frequency group.

Other: High Frequency Exercise Training

Low-Frequency Training

EXPERIMENTAL

Exercise performed on a stationary bike two times per week. Total weekly exercise volume (the product of intensity, duration, and frequency) will be matched between groups. Intensity will be the same, so the low-frequency group will perform double the duration of exercise in each session compared to the high-frequency group.

Other: Low Frequency Exercise Training

Interventions

High Frequency Exercise Training OTHER

Two sessions per week of high-intensity interval training (30 min each) and two sessions per week of continuous endurance exercise (30 min each). All exercise sessions will be performed on a stationary bike under supervision by an investigator.

High-Frequency Training

Low Frequency Exercise Training OTHER

One session per week of high-intensity interval training (60 min) and one session per week of continuous endurance exercise (60 min). All exercise sessions will be performed on a stationary bike under supervision by an investigator.

Low-Frequency Training

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• provide written informed consent
• complete and pass the Get Active Questionnaire (GAQ), a physical activity readiness screening tool

You may not qualify if:

• classified as obese (BMI \> 30 kg/m\^2)
• taking medications that are known to affect cardiovascular and/or metabolic responses to exercise (including but not limited to beta-blockers, anti-inflammatories, anti-coagulants, insulin, etc.)
• dieting for weight loss or following a low carbohydrate diet
• smoking or using tobacco products within the previous year
• consuming excessive amounts of alcohol (\>21 units/week)
• having known health problems such as renal or gastrointestinal disorders, metabolic disease, heart disease, vascular disease, arthritis, diabetes, respiratory disease, uncontrolled blood pressure, dizziness, thyroid problems, or any other health conditions that may confound results
• having orthopedic issues that limit exercise performance
• using an investigational drug product within the last 30 days
• are pregnant
• have donated blood in the previous 90 days
• being highly trained or engaging in training more than 4 times per week
• do not understand English

Sponsors & Collaborators

• University of Calgary: lead
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

Human Performance Lab, University of Calgary

Calgary, Alberta, T2N 1N4, Canada

Location

Related Publications (1)

• Tripp TR, Ghitter RS, Kontro H, Hargrave SJ, Gibala MJ, Aboodarda SJ, MacInnis MJ. Cardiorespiratory Fitness Improvements Following Low-Frequency Training Are Not Inferior to High-Frequency Training Matched for Intensity and Volume. Scand J Med Sci Sports. 2025 Feb;35(2):e70024. doi: 10.1111/sms.70024.

  PMID: 39921357 DERIVED

MeSH Terms

Conditions

Motor Activity

Condition Hierarchy (Ancestors)

Behavior

Study Officials

• Martin J MacInnis, PhD

  University of Calgary

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Participants will undergo the same baseline testing before being pseudo-randomly (block randomization) allocated to one of two groups, each following a different exercise training program for eight weeks.

Study Record Dates

• First Submitted: May 28, 2023
• First Posted: June 18, 2023
• Study Start: May 22, 2023
• Primary Completion: June 28, 2024
• Study Completion: June 28, 2024
• Last Updated: July 11, 2024

Record last verified: 2024-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)