xml: <clinical_study>
    <!-- This xml conforms to an XML Schema at:
      https://clinicaltrials.gov/ct2/html/images/info/public.xsd -->
    <required_header>
      <download_date>ClinicalTrials.gov processed this data on September 20, 2023</download_date>
      <link_text>Link to the current ClinicalTrials.gov record.</link_text>
      <url>https://clinicaltrials.gov/ct2/show/NCT05988606</url>
    </required_header>
    <id_info>
      <org_study_id>21-02-4359</org_study_id>
      <nct_id>NCT05988606</nct_id>
    </id_info>
    <brief_title>Work Rate Adjustments During a High-intensity Interval Training on a Stationary Bike in a Hot and Temperate Environment</brief_title>
    <official_title>Acute Work Rate Adjustments During High-intensity Interval Training in a Hot and Temperate Environment</official_title>
    <sponsors>
      <lead_sponsor>
        <agency>University of Alabama, Tuscaloosa</agency>
        <agency_class>Other</agency_class>
      </lead_sponsor>
    </sponsors>
    <source>University of Alabama, Tuscaloosa</source>
    <oversight_info>
      <has_dmc>No</has_dmc>
      <is_fda_regulated_drug>No</is_fda_regulated_drug>
      <is_fda_regulated_device>No</is_fda_regulated_device>
    </oversight_info>
    <brief_summary>
      <textblock>
        The goal of this repeated measures study is to evaluate acute work rate adjustments during&#xD;
        high-intensity interval training (HIIT) in a hot and temperate environment in healthy and&#xD;
        active adults when using target heart rate to prescribe the exercise intensity.&#xD;
  &#xD;
        The main questions it aims to answer are:&#xD;
  &#xD;
          -  Will HIIT based on target heart rate in a hot environment result in increased&#xD;
             cardiovascular (i.e., elevated recovery HR) and thermal strain compared to HIIT in a&#xD;
             temperate environment?&#xD;
  &#xD;
          -  Will work rate be lowered to a greater extent during HIIT in a hot environment compared&#xD;
             to a temperate environment in order to maintain target heart rate?&#xD;
  &#xD;
          -  Will maximal aerobic capacity (V̇O2max) decrease to a greater extent after HIIT in the&#xD;
             heat compared to a temperate environment?&#xD;
  &#xD;
        Procedures:&#xD;
  &#xD;
        Participants will complete 5 trials on a cycle ergometer. Trial 1 (Control Visit):&#xD;
        Participants (n = 7) will have their maximal heart rate and V̇O2max measured in a temperate&#xD;
        environment (~22 °C, 40% RH).&#xD;
  &#xD;
        Experimental Trials 2-5: The order of the trials will be counterbalanced and randomly&#xD;
        assigned to participants.&#xD;
  &#xD;
          -  15TEMP: Participants will cycle at 70% of their maximum heart rate for 8 minutes as a&#xD;
             warm-up, followed by one round of HIIT. The HIIT protocol consists of 4 minutes at 90%&#xD;
             of maximum heart rate followed by 3 minutes at 70% of maximum heart rate, totaling 15&#xD;
             minutes, in a temperate environment (~22 °C, 40% RH). After the HIIT session, a graded&#xD;
             exercise test will measure V̇O2max.&#xD;
  &#xD;
          -  15HEAT: Similar to 15TEMP, but participants will perform the HIIT protocol in a hot&#xD;
             environment (~35 °C, 40% RH).&#xD;
  &#xD;
          -  43TEMP: Participants will cycle at 70% of their maximum heart rate for 8 minutes as a&#xD;
             warm-up, followed by the HIIT protocol repeated four times (4 minutes at 90% of maximum&#xD;
             heart rate and 3 minutes at 70% of maximum heart rate), totaling 43 minutes, in a&#xD;
             temperate environment (~22 °C, 40% RH).&#xD;
  &#xD;
          -  43HEAT: Similar to 43TEMP, but participants will perform the HIIT protocol in a hot&#xD;
             environment (~35 °C, 40% RH).&#xD;
      </textblock>
    </brief_summary>
    <overall_status>Completed</overall_status>
    <start_date type="Actual">May 12, 2021</start_date>
    <completion_date type="Actual">November 14, 2021</completion_date>
    <primary_completion_date type="Actual">November 14, 2021</primary_completion_date>
    <phase>N/A</phase>
    <study_type>Interventional</study_type>
    <has_expanded_access>No</has_expanded_access>
    <study_design_info>
      <allocation>Randomized</allocation>
      <intervention_model>Crossover Assignment</intervention_model>
      <intervention_model_description>Participants completed all trials and were compared to themselves.</intervention_model_description>
      <primary_purpose>Other</primary_purpose>
      <masking>None (Open Label)</masking>
    </study_design_info>
    <primary_outcome>
      <measure>Work rate adjustments</measure>
      <time_frame>From the first work interval (min 9-12) to the last work interval (min 37-40).</time_frame>
      <description>In a hot and temperate environment by how much does work rate need to be adjusted to maintain target heart rate?</description>
    </primary_outcome>
    <secondary_outcome>
      <measure>Cardiovascular strain</measure>
      <time_frame>From the first recovery interval (min 13-15) to the last recovery interval (min 41-43).</time_frame>
      <description>In a hot and temperate environment by how much does heart rate in the recovery intervals increase?</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Thermal Strain</measure>
      <time_frame>From the first work interval (min 9-12) to the last work interval (min 37-40).</time_frame>
      <description>In a hot and temperate environment by how much do rectal temperature and skin temperature increase?</description>
    </secondary_outcome>
    <secondary_outcome>
      <measure>Maximal aerobic capacity</measure>
      <time_frame>The end of the 15 min trials compared to the end of the 43 min trials.</time_frame>
      <description>In a hot and temperate environment by how much does maximal aerobic capacity decrease?</description>
    </secondary_outcome>
    <number_of_arms>5</number_of_arms>
    <enrollment type="Actual">7</enrollment>
    <condition>High-Intensity Interval Training</condition>
    <condition>Heat</condition>
    <arm_group>
      <arm_group_label>15TEMP</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Participants cycled at 70% heart rate max for 8 min as a warm-up and then completed one round of HIIT, i.e., 4 min at 90% heart rate max followed by 3 min at 70% heart rate max for a total of 15 minutes in a temperate environment, followed by a graded exercise test to measure maximal aerobic capacity.</description>
    </arm_group>
    <arm_group>
      <arm_group_label>15HEAT</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Participants cycled at 70% heart rate max for 8 min as a warm-up and then completed one round of HIIT, i.e., 4 min at 90% heart rate max followed by 3 min at 70% heart rate max for a total of 15 minutes in a hot environment, followed by a graded exercise test to measure maximal aerobic capacity.</description>
    </arm_group>
    <arm_group>
      <arm_group_label>43TEMP</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Participants cycled at 70% heart rate max for 8 min as a warm-up and then performed the HIIT protocol (4 min at 90% heart rate max and 3 min at 70% heart rate max, repeated 4 times for a total of 43 minutes) in a temperate environment followed by a graded exercise test to measure maximal aerobic capacity.</description>
    </arm_group>
    <arm_group>
      <arm_group_label>43HEAT</arm_group_label>
      <arm_group_type>Experimental</arm_group_type>
      <description>Participants cycled at 70% heart rate max for 8 min as a warm-up and then performed the HIIT protocol (4 min at 90% heart rate max and 3 min at 70% heart rate max, repeated 4 times for a total of 43 minutes) in a hot environment followed by a graded exercise test to measure maximal aerobic capacity.</description>
    </arm_group>
    <arm_group>
      <arm_group_label>Control</arm_group_label>
      <arm_group_type>No Intervention</arm_group_type>
      <description>Participants completed a graded exercise test on a stationary bicycle in a temperate environment (~ 22 °C (72 °F), ~40% RH) to measure maximal aerobic capacity and maximal heart rate.</description>
    </arm_group>
    <intervention>
      <intervention_type>Behavioral</intervention_type>
      <intervention_name>15 minutes of high-intensity interval training</intervention_name>
      <description>Participants completed an 8 min warm-up and 1 round of high-intensity interval training</description>
      <arm_group_label>15HEAT</arm_group_label>
      <arm_group_label>15TEMP</arm_group_label>
    </intervention>
    <intervention>
      <intervention_type>Behavioral</intervention_type>
      <intervention_name>43 minutes of high-intensity interval training</intervention_name>
      <description>Participants completed an 8 min warm-up and 5 rounds of high-intensity interval training</description>
      <arm_group_label>43HEAT</arm_group_label>
      <arm_group_label>43TEMP</arm_group_label>
    </intervention>
    <intervention>
      <intervention_type>Other</intervention_type>
      <intervention_name>Hot environment</intervention_name>
      <description>Participants exercised in a hot environment, ~ 35 °C, ~40% relative humidity.</description>
      <arm_group_label>15HEAT</arm_group_label>
      <arm_group_label>43HEAT</arm_group_label>
    </intervention>
    <intervention>
      <intervention_type>Other</intervention_type>
      <intervention_name>Temperate environment</intervention_name>
      <description>Participants exercised in a temperate environment, ~ 22 °C, ~40% relative humidity.</description>
      <arm_group_label>15TEMP</arm_group_label>
      <arm_group_label>43TEMP</arm_group_label>
    </intervention>
    <eligibility>
      <criteria>
        <textblock>
          Inclusion Criteria:&#xD;
  &#xD;
            -  Participants were healthy males and females who are 18 to 39 years of age,&#xD;
               recreationally active as defined by the American College of Sports Medicine,&#xD;
               performing moderate-intensity aerobic exercise 30 min or more per session for at least&#xD;
               3 sessions per week for at least the past 3 months, and free of metabolic,&#xD;
               cardiovascular, and renal disease&#xD;
  &#xD;
          Exclusion Criteria:&#xD;
  &#xD;
            -  Individuals classified as needing medical clearance according to American College of&#xD;
               Sports Medicine (ACSM) Guidelines were not allowed to participate. Needing medical&#xD;
               clearance is defined by ACSM as 1) not being physically active and having known&#xD;
               cardiovascular, metabolic, or renal disease and asymptomatic; 2) not being physically&#xD;
               active and having any signs or symptoms suggestive of cardiovascular, metabolic, or&#xD;
               renal disease; 3) participating in regular exercise and having known cardiovascular,&#xD;
               metabolic, or renal disease and asymptomatic; or 4) participating in regular exercise&#xD;
               and having any signs or symptoms suggestive of cardiovascular, metabolic, or renal&#xD;
               disease .&#xD;
        </textblock>
      </criteria>
      <gender>All</gender>
      <minimum_age>18 Years</minimum_age>
      <maximum_age>39 Years</maximum_age>
      <healthy_volunteers>Accepts Healthy Volunteers</healthy_volunteers>
    </eligibility>
    <location>
      <facility>
        <name>The University of Alabama</name>
        <address>
          <city>Tuscaloosa</city>
          <state>Alabama</state>
          <zip>35487</zip>
          <country>United States</country>
        </address>
      </facility>
    </location>
    <location_countries>
      <country>United States</country>
    </location_countries>
    <verification_date>August 2023</verification_date>
    <study_first_submitted>August 4, 2023</study_first_submitted>
    <study_first_submitted_qc>August 4, 2023</study_first_submitted_qc>
    <study_first_posted type="Actual">August 14, 2023</study_first_posted>
    <last_update_submitted>August 4, 2023</last_update_submitted>
    <last_update_submitted_qc>August 4, 2023</last_update_submitted_qc>
    <last_update_posted type="Actual">August 14, 2023</last_update_posted>
    <responsible_party>
      <responsible_party_type>Sponsor</responsible_party_type>
    </responsible_party>
    <patient_data>
      <sharing_ipd>No</sharing_ipd>
    </patient_data>
    <!-- Results have not yet been posted for this study                                          -->
  </clinical_study>
  
  
text: download date: ClinicalTrials.gov processed this data on September 20, 2023
  link text: Link to the current ClinicalTrials.gov record.
  url: https://clinicaltrials.gov/ct2/show/NCT05988606
  org study id: 21-02-4359
  nct id: NCT05988606
  lead sponsor: 
  has dmc: No
  is fda regulated drug: No
  is fda regulated device: No
  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).
  allocation: Randomized
  intervention model: Crossover Assignment
  intervention model description: Participants completed all trials and were compared to themselves.
  primary purpose: Other
  masking: None (Open Label)
  measure: Work rate adjustments
  time frame: From the first work interval (min 9-12) to the last work interval (min 37-40).
  description: In a hot and temperate environment by how much does work rate need to be adjusted to maintain target heart rate?
  measure: Cardiovascular strain
  time frame: From the first recovery interval (min 13-15) to the last recovery interval (min 41-43).
  description: In a hot and temperate environment by how much does heart rate in the recovery intervals increase?
  measure: Thermal Strain
  time frame: From the first work interval (min 9-12) to the last work interval (min 37-40).
  description: In a hot and temperate environment by how much do rectal temperature and skin temperature increase?
  measure: Maximal aerobic capacity
  time frame: The end of the 15 min trials compared to the end of the 43 min trials.
  description: In a hot and temperate environment by how much does maximal aerobic capacity decrease?
  arm group label: 15TEMP
  arm group type: Experimental
  description: Participants cycled at 70% heart rate max for 8 min as a warm-up and then completed one round of HIIT, i.e., 4 min at 90% heart rate max followed by 3 min at 70% heart rate max for a total of 15 minutes in a temperate environment, followed by a graded exercise test to measure maximal aerobic capacity.
  arm group label: 15HEAT
  arm group type: Experimental
  description: Participants cycled at 70% heart rate max for 8 min as a warm-up and then completed one round of HIIT, i.e., 4 min at 90% heart rate max followed by 3 min at 70% heart rate max for a total of 15 minutes in a hot environment, followed by a graded exercise test to measure maximal aerobic capacity.
  arm group label: 43TEMP
  arm group type: Experimental
  description: Participants cycled at 70% heart rate max for 8 min as a warm-up and then performed the HIIT protocol (4 min at 90% heart rate max and 3 min at 70% heart rate max, repeated 4 times for a total of 43 minutes) in a temperate environment followed by a graded exercise test to measure maximal aerobic capacity.
  arm group label: 43HEAT
  arm group type: Experimental
  description: Participants cycled at 70% heart rate max for 8 min as a warm-up and then performed the HIIT protocol (4 min at 90% heart rate max and 3 min at 70% heart rate max, repeated 4 times for a total of 43 minutes) in a hot environment followed by a graded exercise test to measure maximal aerobic capacity.
  arm group label: Control
  arm group type: No Intervention
  description: Participants completed a graded exercise test on a stationary bicycle in a temperate environment (~ 22 °C (72 °F), ~40% RH) to measure maximal aerobic capacity and maximal heart rate.
  intervention type: Behavioral
  intervention name: 15 minutes of high-intensity interval training
  description: Participants completed an 8 min warm-up and 1 round of high-intensity interval training
  arm group label: 15HEAT
  arm group label: 15TEMP
  intervention type: Behavioral
  intervention name: 43 minutes of high-intensity interval training
  description: Participants completed an 8 min warm-up and 5 rounds of high-intensity interval training
  arm group label: 43HEAT
  arm group label: 43TEMP
  intervention type: Other
  intervention name: Hot environment
  description: Participants exercised in a hot environment, ~ 35 °C, ~40% relative humidity.
  arm group label: 15HEAT
  arm group label: 43HEAT
  intervention type: Other
  intervention name: Temperate environment
  description: Participants exercised in a temperate environment, ~ 22 °C, ~40% relative humidity.
  arm group label: 15TEMP
  arm group label: 43TEMP
  criteria: 
  gender: All
  minimum age: 18 Years
  maximum age: 39 Years
  healthy volunteers: Accepts Healthy Volunteers
  facility: 
  country: United States
  responsible party type: Sponsor
  sharing ipd: No