CompletedNot Applicable

Work Rate Adjustments During a High-intensity Interval Training on a Stationary Bike in a Hot and Temperate Environment

United States7 participantsStarted 2021-05-12

Plain-language summary

The goal of this repeated measures study is to evaluate acute work rate adjustments during high-intensity interval training (HIIT) in a hot and temperate environment in healthy and active adults when using target heart rate to prescribe the exercise intensity. The main questions it aims to answer are: * Will HIIT based on target heart rate in a hot environment result in increased cardiovascular (i.e., elevated recovery HR) and thermal strain compared to HIIT in a temperate environment? * Will work rate be lowered to a greater extent during HIIT in a hot environment compared to a temperate environment in order to maintain target heart rate? * Will maximal aerobic capacity (V̇O2max) decrease to a greater extent after HIIT in the heat compared to a temperate environment? Procedures: Participants will complete 5 trials on a cycle ergometer. Trial 1 (Control Visit): Participants (n = 7) will have their maximal heart rate and V̇O2max measured in a temperate environment (\~22 °C, 40% RH). Experimental Trials 2-5: The order of the trials will be counterbalanced and randomly assigned to participants. * 15TEMP: Participants will cycle at 70% of their maximum heart rate for 8 minutes as a warm-up, followed by one round of HIIT. The HIIT protocol consists of 4 minutes at 90% of maximum heart rate followed by 3 minutes at 70% of maximum heart rate, totaling 15 minutes, in a temperate environment (\~22 °C, 40% RH). After the HIIT session, a graded exercise test will measure V̇O2max. * 15HEAT: Similar to 15TEMP, but participants will perform the HIIT protocol in a hot environment (\~35 °C, 40% RH). * 43TEMP: Participants will cycle at 70% of their maximum heart rate for 8 minutes as a warm-up, followed by the HIIT protocol repeated four times (4 minutes at 90% of maximum heart rate and 3 minutes at 70% of maximum heart rate), totaling 43 minutes, in a temperate environment (\~22 °C, 40% RH). * 43HEAT: Similar to 43TEMP, but participants will perform the HIIT protocol in a hot environment (\~35 °C, 40% RH).

Who can participate

Age range

18 Years – 39 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * Participants were healthy males and females who are 18 to 39 years of age, recreationally active as defined by the American College of Sports Medicine, performing moderate-intensity aerobic exercise 30 min or more per session for at least 3 sessions per week for at least the past 3 months, and free of metabolic, cardiovascular, and renal disease Exclusion Criteria: * Individuals classified as needing medical clearance according to American College of Sports Medicine (ACSM) Guidelines were not allowed to participate. Needing medical clearance is defined by ACSM as 1) not being physically active and having known cardiovascular, metabolic, or renal disease and asymptomatic; 2) not being physically active and having any signs or symptoms suggestive of cardiovascular, metabolic, or renal disease; 3) participating in regular exercise and having known cardiovascular, metabolic, or renal disease and asymptomatic; or 4) participating in regular exercise and having any signs or symptoms suggestive of cardiovascular, metabolic, or renal disease .

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Work rate adjustments

Timeframe: From the first work interval (min 9-12) to the last work interval (min 37-40).

Trial details

NCT IDNCT05988606

SponsorUniversity of Alabama, Tuscaloosa

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2021-11-14

View on ClinicalTrials.gov More High-Intensity Interval Training trials