Ignite Creation Date:
2024-05-06 @ 3:40 PM
Last Modification Date:
2024-10-26 @ 1:54 PM
Study NCT ID:
NCT04715711
Status:
COMPLETED
Last Update Posted:
2021-08-03
First Post:
2021-01-14
Brief Title:
Physiological and Thermoregulatory Responses of Body Cooling During Cycling in a Hot Environment
Sponsor:
University of Connecticut
Organization:
University of Connecticut
Study Overview
Official Title:
Physiological and Thermoregulatory Responses of Body Cooling During Cycling in a Hot Environment PYTHON
Status:
COMPLETED
Status Verified Date:
2021-08
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
PYTHON
Brief Summary:
BHSAI is developing a computational system that provides early alerts of a rise in core body temperature to help reduce the risk of heat injury in the field and during training The goal of the body temperature alerting system is to use it during rest exercise in the heat and during body cooling Using this system during cooling will allow healthcare professionals and military personnel monitor core temperature to ensure cooling is effective and prevent hypothermia Therefore the primary purpose of this investigation is to validate a body temperature alerting system using physiological responses that occur during rest exercise in the heat and during body cooling Multiple cooling modalities will be validated This study is expanding on a previous intervention IRBH20-0010 BHSAI Cooling Study but will examine body cooling during more intense exercise and while cycling We will also examine the effectiveness of each cooling modality passive cooling mist-fan cooling handforearm immersion ice towel on physiological variables after exercise in the heat
Detailed Description:
Design
The study will be completed in the following timeline
Visit 1 Baseline and VO2max Testing
Vist 2 Metabolic Heat Production Visit
Visit 3-6 Trial 1 2 3 4
Visit specific information is described below however specific data collection protocols for dependent variables and procedures are included below the description of the study design Participants will be asked to sign a photovideo release form Appendix H to be used in research projects scientific publicationsconferences and for educational purposes Participants may be videoed or photographed while exercising or resting in the environmental chamber Participants will be assigned after medical clearance is granted
Visit 1 Baseline and VO2max Testing
Participants who are approved to participate will be scheduled for a baseline and VO2max testing day Basal metabolic rate BMR will be measured upon arrival during the baseline visit The participant will lay supine with a ventilated hood covering their head and torso The ventilated hood will be attached to a hose connected to a metabolic cart The metabolic cart will continuously measure respiratory exchange ratio oxygen consumption and substrate utilization The participant will remain under the hood for approximately 30 minutes Upon completion of BMR participants will provide a urine sample in a clean urine cup Urine specific gravity and urine color will be assessed Nude body mass will also be recorded Privacy will be afforded for each participant while obtaining body mass measures by taking measurements with the participant alone in a private room behind a solid closed door and the research reading the scale outside of the room Participants will only be permitted to continue to the VO2max test if the euhydrated criteria of a urine specific gravity USG 1025 is met If the participant arrives with a USG between 1020 and 1025 the subject will be asked to drink 500 mL of water to ensure proper hydration status If USG is greater than 1025 the subject will be rescheduled for a different day Height will be measured with a tape measure on Visit 1 Percent body fat will be measured using Air displacement plethysmography BodPod Cosmed Software Version 42 Concord CA USA This will take less than 5 minutes to complete This information will be used to describe the subject demographics Participants will also be asked to complete a maximal oxygen uptake VO2max test on a treadmill and on a cycle ergometer in a thermoneutral environment with about 30 minutes to one hour between This test will provide aerobic fitness levels of the participants which will be compared between the two exercise protocols Participants will also be asked about their average weekly physical activity Appendix K This visit will take approximately 1-2 hours
Visit 2 Metabolic Heat Production Visit
In order to prescribe appropriate exercise intensity heat production must be controlled Heat production will be prescribed utilizing a graded exercise test 3-5 minute stages in the heat same environmental temperature as trials that will measure metabolic data via collection of expired air utilizing 2-way non-rebreathing mask in order to calculate heat production and appropriately choose cycling intensities to compare between groups of research participants This test will occur following the baseline visit The study procedures will mimic those of trials described below with the exception of the exercise protocol The exercise protocol will take approximately 20 minutes to complete It will include 5 stages of exercise graded stages The participant will wear the ACU during this visit
Visit 3-6 Trials 1-4
Participant numbers will be randomly assigned and 4 trials mist-fan forearm passive cooling ice towel will be ordered with a random number generator and assigned to a participant number
These orders will be counterbalanced between participants to ensure that there is not an order effect Each participant will complete four trials as part of the study Participants will be allowed to make-up trial visits if they are sick suffer an injury or do not meet hydration requirements Participants will be asked if they have a current illness or taking medications to determine whether they can complete the exercise trial The participants visit will be rescheduled if they have a fever current illness or taking medications that influence body temperature Participants will complete four trials on four separate days
Trial
Cooling Intervention
1
Passive Cooling
2
Mist-fan Cooling
3
Forearm Immersion
4
Ice Towel
The exercise protocol and recovery portions of this study will be conducted in a climatic chamber with ambient temperature approximately 30-40C and relative humidity at approximately 30-70 Participants will drink ad libitum throughout the exercise trial
Upon arrival to the lab participants will be asked to indicate if they have consumed alcohol or caffeine in the last 24 hours and 12 hours respectively They will not be asked to specify exactly what they have consumed but if they provide a positive indication their trial will be rescheduled for another day Participants will provide a small urine sample in a clean urine cup and a nude body mass will be measured Upon arrival to the lab hydration status will be assessed by urine specific gravity nude body mass and urine color Participants will only be permitted to continue to the exercise trial if the euhydrated criteria of a urine specific gravity USG 1025 is met If the participant arrives with a USG between 1020 and 1025 the subject will be asked to drink 500 mL of water to ensure proper hydration status If USG is greater than 1025 then the subject will be rescheduled for a different day Participants will be given instructions at the prior visit about how to obtain desired hydration status for the upcoming trial Researchers will insert an esophageal probe Only trained personnel are permitted to insert the esophageal probe no undergraduates will be allowed Participants will insert a rectal probe and wear a heart rate monitor strap Additionally participants will wear 9-site Biopac skin temperature sensors Researchers will apply the skin temperature sensors with medical tape to the participants chest upper arm forearm thigh neck abdomen thigh back and calf anterior and posterior Participants will also wear iButtons wireless skin temperature sensors on their chest upper arm forearm thigh and calf anterior and posterior The participants will also be asked to complete a subjective sleep questionnaire upon arriving to the lab Participants will wear an active combat uniform ACU during the exercise trials Three ADU sizes for the blouse and pants small medium large will be available for the participants A belt will be used to ensure the ACU fits appropriately Participants will not be able to keep the ACU- ADUs will be washed according to manufacturers instructions and re-used for participants ADU manufacturers instructions is identical to standard washing cycle detergent and washing machine dry The ACU will be weighed before and after use to measure sweat captured in the clothing Participants will wear the wrist-based devices provided by BHSAI on their non-dominant arm throughout the testing The wrist device must be placed approximately 1-inch proximal to the wrist and be fitted snugly for accurate heart-rate measurements The wrist device is used to estimate heart rate using infrared technology The wrist device estimates of heart rate will be compared to the polar heart rate monitor gold standard The body alerting system uses heart rate from the wrist device and the environmental conditions to estimate body temperature The sponsor of the study will use rectal temperature and the 7-site skin temperature sensors to alter the algorithm not in real time- from the collected data to better estimate body temperature The future goal is to have the body alerting system imbedded in the watch Participants will wear another wrist-based device WHOOP on the arm that does not have the BHSAI device The WHOOP device will monitor heart rate variability and sleep Participants will be asked to wear this device daily for the duration of the study
Participants will enter the environmental chamber and sit for 30 minutes to become equilibrated The environmental chamber will be set to 30-40C ambient temperature 30-70 relative humidity After baseline measures of heart rate rectal temperature participants will complete the perceptual indices Participants will also complete an environmental symptoms questionnaire ESQ
The trial will consist of two 40-minute intervals of cycling from 7Wkg to 15 Wkg Each 40-minute exercise block will be followed by a rest break where cooling will occur Participants will be allowed to drink ad libitum throughout the exercise trial The participant will be cooled for approximately 30 minutes with their assigned cooling modality Rectal and esophageal temperature skin temperature heart rate perceptual measures and mood POMS described below will be collected at various time points before during and after exercise and cooling Metabolic heat production will be measured using indirect calorimetry mask connected to metabolic cart during all four trials
Passive Cooling Participants will be asked to sit in a chair in the climate chamber for passive cooling
Mist-fan cooling A mist-fan will be placed next to the participant and will mist-fan only their hands and forearms during mist-fan cooling Participants will be asked to roll up their ADU sleeves to increase skin surface area The temperature of the mist and wind speed of the fan will be recorded
Forearm immersion The participant will place their forearm in approximately 20C water during forearm immersion
Ice Towel a towel that can hold water for extended periods will be used and submerged in an ice-water mixture 2 C Researchers will gently squeeze the towel to remove excess water but remain saturated with water and then apply to both forearms and hands snuggly so that there is no air gap between the towel and the extremity Apply for 1-5 minutes and then replace it with another fresh cold towel This step would ensure that the forearms and hands have near about constant application temperature as the towel would get warm over the application period The process will be repeated for the entire cooling duration
Data collection will be divided into two separate phases A pilot study will be first conducted in which the first two participants will complete all study laboratory visits Data from those trials will be shared with the sponsor for review before continuation of data collection Participants will undergo the same procedures for the pilot testing as regular testing Pilot testing data will be included in the dataset Following approval from the sponsor data collection will resume Each trial will be approximately 4 hours
All devices will be properly cleaned according to manufacturers instruction prior to use by other participants
The study will be completed in the following timeline
Visit 1 Baseline and VO2max Testing
Vist 2 Metabolic Heat Production Visit
Visit 3-6 Trial 1 2 3 4
Visit specific information is described below however specific data collection protocols for dependent variables and procedures are included below the description of the study design Participants will be asked to sign a photovideo release form Appendix H to be used in research projects scientific publicationsconferences and for educational purposes Participants may be videoed or photographed while exercising or resting in the environmental chamber Participants will be assigned after medical clearance is granted
Visit 1 Baseline and VO2max Testing
Participants who are approved to participate will be scheduled for a baseline and VO2max testing day Basal metabolic rate BMR will be measured upon arrival during the baseline visit The participant will lay supine with a ventilated hood covering their head and torso The ventilated hood will be attached to a hose connected to a metabolic cart The metabolic cart will continuously measure respiratory exchange ratio oxygen consumption and substrate utilization The participant will remain under the hood for approximately 30 minutes Upon completion of BMR participants will provide a urine sample in a clean urine cup Urine specific gravity and urine color will be assessed Nude body mass will also be recorded Privacy will be afforded for each participant while obtaining body mass measures by taking measurements with the participant alone in a private room behind a solid closed door and the research reading the scale outside of the room Participants will only be permitted to continue to the VO2max test if the euhydrated criteria of a urine specific gravity USG 1025 is met If the participant arrives with a USG between 1020 and 1025 the subject will be asked to drink 500 mL of water to ensure proper hydration status If USG is greater than 1025 the subject will be rescheduled for a different day Height will be measured with a tape measure on Visit 1 Percent body fat will be measured using Air displacement plethysmography BodPod Cosmed Software Version 42 Concord CA USA This will take less than 5 minutes to complete This information will be used to describe the subject demographics Participants will also be asked to complete a maximal oxygen uptake VO2max test on a treadmill and on a cycle ergometer in a thermoneutral environment with about 30 minutes to one hour between This test will provide aerobic fitness levels of the participants which will be compared between the two exercise protocols Participants will also be asked about their average weekly physical activity Appendix K This visit will take approximately 1-2 hours
Visit 2 Metabolic Heat Production Visit
In order to prescribe appropriate exercise intensity heat production must be controlled Heat production will be prescribed utilizing a graded exercise test 3-5 minute stages in the heat same environmental temperature as trials that will measure metabolic data via collection of expired air utilizing 2-way non-rebreathing mask in order to calculate heat production and appropriately choose cycling intensities to compare between groups of research participants This test will occur following the baseline visit The study procedures will mimic those of trials described below with the exception of the exercise protocol The exercise protocol will take approximately 20 minutes to complete It will include 5 stages of exercise graded stages The participant will wear the ACU during this visit
Visit 3-6 Trials 1-4
Participant numbers will be randomly assigned and 4 trials mist-fan forearm passive cooling ice towel will be ordered with a random number generator and assigned to a participant number
These orders will be counterbalanced between participants to ensure that there is not an order effect Each participant will complete four trials as part of the study Participants will be allowed to make-up trial visits if they are sick suffer an injury or do not meet hydration requirements Participants will be asked if they have a current illness or taking medications to determine whether they can complete the exercise trial The participants visit will be rescheduled if they have a fever current illness or taking medications that influence body temperature Participants will complete four trials on four separate days
Trial
Cooling Intervention
1
Passive Cooling
2
Mist-fan Cooling
3
Forearm Immersion
4
Ice Towel
The exercise protocol and recovery portions of this study will be conducted in a climatic chamber with ambient temperature approximately 30-40C and relative humidity at approximately 30-70 Participants will drink ad libitum throughout the exercise trial
Upon arrival to the lab participants will be asked to indicate if they have consumed alcohol or caffeine in the last 24 hours and 12 hours respectively They will not be asked to specify exactly what they have consumed but if they provide a positive indication their trial will be rescheduled for another day Participants will provide a small urine sample in a clean urine cup and a nude body mass will be measured Upon arrival to the lab hydration status will be assessed by urine specific gravity nude body mass and urine color Participants will only be permitted to continue to the exercise trial if the euhydrated criteria of a urine specific gravity USG 1025 is met If the participant arrives with a USG between 1020 and 1025 the subject will be asked to drink 500 mL of water to ensure proper hydration status If USG is greater than 1025 then the subject will be rescheduled for a different day Participants will be given instructions at the prior visit about how to obtain desired hydration status for the upcoming trial Researchers will insert an esophageal probe Only trained personnel are permitted to insert the esophageal probe no undergraduates will be allowed Participants will insert a rectal probe and wear a heart rate monitor strap Additionally participants will wear 9-site Biopac skin temperature sensors Researchers will apply the skin temperature sensors with medical tape to the participants chest upper arm forearm thigh neck abdomen thigh back and calf anterior and posterior Participants will also wear iButtons wireless skin temperature sensors on their chest upper arm forearm thigh and calf anterior and posterior The participants will also be asked to complete a subjective sleep questionnaire upon arriving to the lab Participants will wear an active combat uniform ACU during the exercise trials Three ADU sizes for the blouse and pants small medium large will be available for the participants A belt will be used to ensure the ACU fits appropriately Participants will not be able to keep the ACU- ADUs will be washed according to manufacturers instructions and re-used for participants ADU manufacturers instructions is identical to standard washing cycle detergent and washing machine dry The ACU will be weighed before and after use to measure sweat captured in the clothing Participants will wear the wrist-based devices provided by BHSAI on their non-dominant arm throughout the testing The wrist device must be placed approximately 1-inch proximal to the wrist and be fitted snugly for accurate heart-rate measurements The wrist device is used to estimate heart rate using infrared technology The wrist device estimates of heart rate will be compared to the polar heart rate monitor gold standard The body alerting system uses heart rate from the wrist device and the environmental conditions to estimate body temperature The sponsor of the study will use rectal temperature and the 7-site skin temperature sensors to alter the algorithm not in real time- from the collected data to better estimate body temperature The future goal is to have the body alerting system imbedded in the watch Participants will wear another wrist-based device WHOOP on the arm that does not have the BHSAI device The WHOOP device will monitor heart rate variability and sleep Participants will be asked to wear this device daily for the duration of the study
Participants will enter the environmental chamber and sit for 30 minutes to become equilibrated The environmental chamber will be set to 30-40C ambient temperature 30-70 relative humidity After baseline measures of heart rate rectal temperature participants will complete the perceptual indices Participants will also complete an environmental symptoms questionnaire ESQ
The trial will consist of two 40-minute intervals of cycling from 7Wkg to 15 Wkg Each 40-minute exercise block will be followed by a rest break where cooling will occur Participants will be allowed to drink ad libitum throughout the exercise trial The participant will be cooled for approximately 30 minutes with their assigned cooling modality Rectal and esophageal temperature skin temperature heart rate perceptual measures and mood POMS described below will be collected at various time points before during and after exercise and cooling Metabolic heat production will be measured using indirect calorimetry mask connected to metabolic cart during all four trials
Passive Cooling Participants will be asked to sit in a chair in the climate chamber for passive cooling
Mist-fan cooling A mist-fan will be placed next to the participant and will mist-fan only their hands and forearms during mist-fan cooling Participants will be asked to roll up their ADU sleeves to increase skin surface area The temperature of the mist and wind speed of the fan will be recorded
Forearm immersion The participant will place their forearm in approximately 20C water during forearm immersion
Ice Towel a towel that can hold water for extended periods will be used and submerged in an ice-water mixture 2 C Researchers will gently squeeze the towel to remove excess water but remain saturated with water and then apply to both forearms and hands snuggly so that there is no air gap between the towel and the extremity Apply for 1-5 minutes and then replace it with another fresh cold towel This step would ensure that the forearms and hands have near about constant application temperature as the towel would get warm over the application period The process will be repeated for the entire cooling duration
Data collection will be divided into two separate phases A pilot study will be first conducted in which the first two participants will complete all study laboratory visits Data from those trials will be shared with the sponsor for review before continuation of data collection Participants will undergo the same procedures for the pilot testing as regular testing Pilot testing data will be included in the dataset Following approval from the sponsor data collection will resume Each trial will be approximately 4 hours
All devices will be properly cleaned according to manufacturers instruction prior to use by other participants
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None