FirefighterNCT05287594
Feasibility of a Train-the-Trainer Delivered Exercise Intervention in Firefighters
A study testing Integrated Exercise Program in people with Firefighter and High Intensity Interval Training, run by University of North Carolina, Chapel Hill at 1 site in United States.
Trial summary
Purpose: To collect and report feasibility data for conducting a future cluster randomized trial to evaluate the efficacy of a TRAINER delivered integrated exercise program in career firefighters, and to determine intervention fidelity and preliminary effects of a TRAINER delivered integrated exercise program in… Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Firefighter, High Intensity Interval Training
- What is being tested?
- Integrated Exercise Program
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 55 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2023to 29 Sep 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Provide informed consent prior to any study procedures are performed
- Medically cleared for fire suppression duties
- A career firefighter from a local department (Carrboro, Chapel Hill, and Durham)
Who cannot join
- Highly active firefighters, defined as performing 4 or more days/week of vigorous exercise
- Pregnancy
- Recent injury preventing their participation in the exercise routine
- Involved in an active workers' compensation or personal injury case
Trial locations and contacts
1 site in 1 country.
About this study
Purpose: To collect and report feasibility data for conducting a future cluster randomized trial to evaluate the efficacy of a TRAINER delivered integrated exercise program in career firefighters, and to determine intervention fidelity and preliminary effects of a TRAINER delivered integrated exercise program in career firefighters.
Participants: 52 career firefighters 18 - 60 years old (40 trainees, 6 trainers, 6 administrators).
Procedures (methods): Enrolled fire stations will be randomly assigned (3:2 allocation ratio) to a TRAINER or wait-list control (CON) group, stratified by city, using computer-generated random numbers. All enrolled firefighters will undergo a series of assessments at baseline (week 0) and post-testing (week 7) following the TRAINER delivered 6-week intervention.
- Conditions
- Firefighter, High Intensity Interval Training
- Being tested
- Integrated Exercise Program
- Keywords
- Firefighter, Train-the-Trainer, High intensity interval training, Neuromuscular warm-up, Fire and Rescue Personnel
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Integrated Exercise ProgramBehavioural
Also called Neuromuscular warm-up, High intensity interval training, HIIT
Neuromuscular warm-up: Each participant will perform a series of dynamic stretches, core stability, balance, and medicine ball exercises. The dynamic stretches include 8 repetitions of 6 stretches targeting the hip and thigh musculature, followed by 3 core stability isometric exercises (curl-up, side bridge, and bird dog). Participants will then perform 2 sets (per leg) of hop-to-stabilization (with a reach) balance exercises, followed by 3 separate medicine ball exercises emphasizing explosive full-body movements.
High Intensity Interval Training (HIIT): HIIT will include a series of high intensity exercise bouts on a stationary bike that includes a 1:1 work-to-rest ratio. Training intensity will be determined from the peak power output obtained during the baseline VO2 peak assessment and progressively increased by the number of bouts and intensity. The number of work bouts will increase from 5 to 8 bouts and the intensity will increase from 90 to 110% of peak power output.
| Study group | Role | What they receive |
|---|---|---|
| TRAINER | Experimental | The TRAINER group will receive an integrated exercise program, led by a peer-trainer, including a neuromuscular warm-up and high intensity interval training at their respective fire stations 2 times per week for 6 weeks. Receives: Behavioral: Integrated Exercise Program |
| Waitlist Control | No intervention | The waitlist control group will not receive training during the course of the study, but will be offered the opportunity to receive the integrated exercise program after the study ends. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Firefighters and Fire Stations Recruited to the Study (Feasibility)
To demonstrate the feasibility of an integrated exercise program. Feasibility will be defined as recruitment of 40 firefighters and the number of fire stations (out of 26 potential) to the study within 14 months.
Measured: Within 14 months
Percentage of Firefighters Retained (Feasibility)
To demonstrate the feasibility of an integrated exercise program. Retention will be determined from the percentage of firefighters retained at post-testing. Retention of 80% or higher will be considered good feasibility.
Measured: Week 7 (post-intervention)
Percentage of Sessions Attended (Feasibility)
To demonstrate the feasibility of an integrated exercise program. Adherence will be determined from the percentage of sessions attended out of total (12) sessions. Adherence of 80% or higher will be considered good feasibility.
Measured: Week 7 (post-intervention)
Qualitative Summaries of Participant Experience in Semi-Structured Interviews (Acceptability)
Acceptability will be assessed by semi-structured interviews with the firefighters, peer-trainers, and departmental administration (e.g. fire chiefs). Qualitative summaries for intrapersonal, interpersonal, and organizational constructs will be reported.
Measured: Week 7 (post-intervention)
Secondary outcomes (11)
Change in cardiorespiratory fitness as measured by VO2 peak during cycle ergometry
Cardiorespiratory fitness will be measured by peak oxygen consumption (VO2 peak). All participants will perform a cycling ergometer test with respiratory gases continuously monitored with open-circuit spirometry (True One 2400®, Parvo-Medics, Inc., Provo, UT). Data will be averaged over 15-second intervals, with the highest 15-second oxygen consumption recorded as the VO2 peak.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in body composition as measured by % body fat from a 4-compartment model
Body composition will be evaluated to determine the effects of the intervention on % body fat. Dual-energy x-ray absorptiometry (DXA;General Electric Lunar iDXA, Chicago, IL) and bioelectrical impedance spectroscopy (BIS; ImpediMed SFB7, Queensland, AU) will be used to determine a gold-standard DXA-derived four-compartment model of % body fat.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in explosive muscle strength as measured by dynamometry
All participants will perform a rapid and maximal isometric muscle action on a calibrated isokinetic dynamometer (CSMi, Stoughton, MA) against a padded and stiff lever arm for 3-4 seconds. The peak rate of torque development will be determined from the peak of the first derivative of the torque-time curve.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in low-back muscular endurance as measured by a modified Biering-Sorensen test
Low-back muscular endurance (time to task failure) will be examined using a modified version of the Biering-Sorensen test, using a variable angle Roman chair (Powerlift, Jefferson, IA).
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in balance as measured by a modified star excursion balance test
Balance will be determined by using a modified star excursion balance test. Following a familiarization, participants will reach with their free limb as far as possible in the anterior, posterolateral, and posteromedial direction relative to the stance leg. Scores will be normalized to leg length.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Fidelity of the neuromuscular warm-up as measured by a rubric across sessions at Week 2
The fidelity of the neuromuscular warm-up will be examined using a scoring rubric. The rubric evaluates the leadership abilities of the trainers and the execution of the exercises by the firefighters. Each item is scored 1 to 5 with 1 indicating no correctness and 5 indicating complete correctness. Items will be summed for a total score. Higher values mean higher fidelity.
Measured: 2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Fidelity of the neuromuscular warm-up as measured by a rubric across sessions at Week 6
The fidelity of the neuromuscular warm-up will be examined using a scoring rubric. The rubric evaluates the leadership abilities of the trainers and the execution of the exercises by the firefighters. Each item is scored 1 to 5 with 1 indicating no correctness and 5 indicating complete correctness. Items will be summed for a total score. Higher values mean higher fidelity.
Measured: 6 weeks (i.e., one of last 2 sessions)
Fidelity of the HIIT protocol as measured by rate of peak power output across sessions at Week 2
Fidelity will be assessed to ensure participant adherence to the intervention protocol in each session. The fidelity of the HIIT protocol will be examined by recording the prescribed peak power output (90-110%) during the training session. Training intensity will be established from a percentage of the baseline peak power output (Watts) achieved during the VO2 peak test. Higher fidelity is indicated as the percent power output more closely approaches the prescribed power output percentage.
Measured: 2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Fidelity of the HIIT protocol as measured by rate of peak power output across sessions at Week 6
Fidelity will be assessed to ensure participant adherence to the intervention protocol in each session. The fidelity of the HIIT protocol will be examined by recording the prescribed peak power output (90-110%) during the training session. Training intensity will be established from a percentage of the baseline peak power output (Watts) achieved during the VO2 peak test. Higher fidelity is indicated as the percent power output more closely approaches the prescribed power output percentage.
Measured: 6 weeks (i.e., one of last 2 sessions)
Change in physical activity as measured by the International Physical Activity Questionnaire-Short Form
Physical activity will be examined using the validated 7-day recall International Physical Activity Questionnaire-Short Form. Higher scores represent greater total metabolic equivalent of task (MET) minutes of physical activity per week based on the following estimates: 3.3 MET units for walking, 4.4 MET units for moderate activity, 8 MET units for vigorous activity. Total MET minutes of physical activity is calculated from the questionnaire using the following calculation:
Total MET-min/week = (Walk METs*min*days) + (Mod METs*min*days) + Vig METs*min*days)
The study will test whether there is a BASELINE-to-POST increase in total scores on the International Physical Activity Questionnaire-Short Form (units: MET minutes/week) for the TRAINER group relative to the waitlist control group. The outcome for each group is computed as the main of the difference of the POST score minus the BASELINE score.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in nutrition as measured by the Rapid Eating Assessment for Participants-Short Form
Nutritional habits will be examined using the validated Rapid Eating Assessment for Participants-Short Form. Responses of 'usually/often' receives 1 point, 'sometimes' receives 2 points, and 'rarely/never or does not apply to me' receives 3 points. Possible scores ranged from 13 to 39 with a higher score indicating better nutritional habits. The study will test whether there is a BASELINE-to-POST increase in total scores on the Rapid Eating Assessment for Participants-Short Form for the TRAINER group relative to the waitlist control group. The outcome for each group is computed as the main of the difference of the POST score minus the BASELINE score.
Measured: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Mar 2022
- Study start1 Apr 2023
- Primary completion26 Sep 2025
- Study completion29 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for FirefighterStudies of the same condition, open and under way.
- More trials run by University of North Carolina, Chapel HillThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two group design where 40 firefighters are cluster randomized (3:2 ratio) into a TRAINER or waitlist control group. There will be 6 trainers who will lead the TRAINER condition. All participants in the TRAINER group and following the intervention in the waitlist control group will receive the same integrated exercise program, led by a peer-trainer, including a neuromuscular warm-up and high intensity interval training at their respective fire stations 2 times per week for 6 weeks.
- Masking
- None (open label)
- Enrolment
- 55 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of North Carolina, Chapel Hill
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute for Occupational Safety and Health (NIOSH/CDC)
- Responsible party
- Sponsor
- Investigators
- Eric Ryan, PhD, Principal investigator, UNC Chapel Hill
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05287594
- Sponsor's protocol ID
- 21-2522
- Status last verified
- Dec 2025
- First submitted
- 9 Mar 2022
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Deidentified individual data that supports the results will be shared beginning 9 to 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with the University of North Carolina (UNC).
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Feasibility of a Train-the-Trainer Delivered Exercise Intervention in Firefighters
- ClinicalTrials.gov ID
- NCT05287594
- Acronym / sponsor ID
- 21-2522
- Conditions
- Firefighter, High Intensity Interval Training
- Keywords
- Firefighter, Train-the-Trainer, High intensity interval training, Neuromuscular warm-up, Fire and Rescue Personnel
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 55 participants (actual)
- Lead sponsor
- University of North Carolina, Chapel HillUniversity, hospital or other
- Collaborators
- National Institute for Occupational Safety and Health (NIOSH/CDC)
- Study start
- 1 Apr 2023 (actual)
- Primary completion
- 26 Sep 2025 (actual)
- Study completion
- 29 Sep 2025 (actual)
- First posted
- 18 Mar 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Purpose: To collect and report feasibility data for conducting a future cluster randomized trial to evaluate the efficacy of a TRAINER delivered integrated exercise program in career firefighters, and to determine intervention fidelity and preliminary effects of a TRAINER delivered integrated exercise program in career firefighters.
Participants: 52 career firefighters 18 - 60 years old (40 trainees, 6 trainers, 6 administrators).
Procedures (methods): Enrolled fire stations will be randomly assigned (3:2 allocation ratio) to a TRAINER or wait-list control (CON) group, stratified by city, using computer-generated random numbers. All enrolled firefighters will undergo a series of assessments at baseline (week 0) and post-testing (week 7) following the TRAINER delivered 6-week intervention.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Two group design where 40 firefighters are cluster randomized (3:2 ratio) into a TRAINER or waitlist control group. There will be 6 trainers who will lead the TRAINER condition. All participants in the TRAINER group and following the intervention in the waitlist control group will receive the same integrated exercise program, led by a peer-trainer, including a neuromuscular warm-up and high intensity interval training at their respective fire stations 2 times per week for 6 weeks.
| Arm | Type | Receives |
|---|---|---|
| TRAINER | Experimental | Behavioral: Integrated Exercise ProgramThe TRAINER group will receive an integrated exercise program, led by a peer-trainer, including a neuromuscular warm-up and high intensity interval training at their respective fire stations 2 times per week for 6 weeks. |
| Waitlist Control | No intervention | –The waitlist control group will not receive training during the course of the study, but will be offered the opportunity to receive the integrated exercise program after the study ends. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Provide informed consent prior to any study procedures are performed
- Medically cleared for fire suppression duties
- A career firefighter from a local department (Carrboro, Chapel Hill, and Durham)
Key exclusion criteria (4 listed)
- Highly active firefighters, defined as performing 4 or more days/week of vigorous exercise
- Pregnancy
- Recent injury preventing their participation in the exercise routine
- Involved in an active workers' compensation or personal injury case
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Integrated Exercise ProgramAlso: Neuromuscular warm-up, High intensity interval training, HIITNeuromuscular warm-up: Each participant will perform a series of dynamic stretches, core stability, balance, and medicine ball exercises. The dynamic stretches include 8 repetitions of 6 stretches targeting the hip and thigh musculature, followed by 3 core stability isometric exercises (curl-up, side bridge, and bird dog). Participants will then perform 2 sets (per leg) of hop-to-stabilization (with a reach) balance exercises, followed by 3 separate medicine ball exercises emphasizing explosive full-body movements. High Intensity Interval Training (HIIT): HIIT will include a series of high intensity exercise bouts on a stationary bike that includes a 1:1 work-to-rest ratio. Training intensity will be determined from the peak power output obtained during the baseline VO2 peak assessment and progressively increased by the number of bouts and intensity. The number of work bouts will increase from 5 to 8 bouts and the intensity will increase from 90 to 110% of peak power output. | Behavioural | TRAINER |
Primary outcome
Number of Firefighters and Fire Stations Recruited to the Study (Feasibility)
Time frame: Within 14 months
To demonstrate the feasibility of an integrated exercise program. Feasibility will be defined as recruitment of 40 firefighters and the number of fire stations (out of 26 potential) to the study within 14 months.
Percentage of Firefighters Retained (Feasibility)
Time frame: Week 7 (post-intervention)
To demonstrate the feasibility of an integrated exercise program. Retention will be determined from the percentage of firefighters retained at post-testing. Retention of 80% or higher will be considered good feasibility.
Percentage of Sessions Attended (Feasibility)
Time frame: Week 7 (post-intervention)
To demonstrate the feasibility of an integrated exercise program. Adherence will be determined from the percentage of sessions attended out of total (12) sessions. Adherence of 80% or higher will be considered good feasibility.
Qualitative Summaries of Participant Experience in Semi-Structured Interviews (Acceptability)
Time frame: Week 7 (post-intervention)
Acceptability will be assessed by semi-structured interviews with the firefighters, peer-trainers, and departmental administration (e.g. fire chiefs). Qualitative summaries for intrapersonal, interpersonal, and organizational constructs will be reported.
11 secondary outcomes
Change in cardiorespiratory fitness as measured by VO2 peak during cycle ergometry
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in body composition as measured by % body fat from a 4-compartment model
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in explosive muscle strength as measured by dynamometry
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in low-back muscular endurance as measured by a modified Biering-Sorensen test
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in balance as measured by a modified star excursion balance test
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Fidelity of the neuromuscular warm-up as measured by a rubric across sessions at Week 2
Time frame: 2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Fidelity of the neuromuscular warm-up as measured by a rubric across sessions at Week 6
Time frame: 6 weeks (i.e., one of last 2 sessions)
Fidelity of the HIIT protocol as measured by rate of peak power output across sessions at Week 2
Time frame: 2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Fidelity of the HIIT protocol as measured by rate of peak power output across sessions at Week 6
Time frame: 6 weeks (i.e., one of last 2 sessions)
Change in physical activity as measured by the International Physical Activity Questionnaire-Short Form
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Change in nutrition as measured by the Rapid Eating Assessment for Participants-Short Form
Time frame: Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Individual participant dataSharing planned: Yes. Deidentified individual data that supports the results will be shared beginning 9 to 36 months following publication provided the investigator who proposes to use the data has approval from an Institutional Review Board (IRB), Independent Ethics Committee (IEC), or Research Ethics Board (REB), as applicable, and executes a data use/sharing agreement with the University of North Carolina (UNC).
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Eric Ryan, PhD principal investigator
UNC Chapel Hill
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Integrated Exercise Program in people with Firefighter and High Intensity Interval Training, run by University of North Carolina, Chapel Hill at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Firefighters and Fire Stations Recruited to the Study (Feasibility) (time frame: Within 14 months). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025; AzTrials last refreshed its copy on 6 Nov 2026.