Feasibility of a Train-the-Trainer Delivered Exercise Intervention in Firefighters

High Intensity Interval Training Clinical Trial

Official title:

Feasibility of a Train-the-Trainer Delivered Exercise Intervention in Firefighters

Clinical Trial Details — Status: Enrolling by invitation

Administrative data

• NCT number: NCT05287594
• Other study ID #: 21-2522
• Status: Enrolling by invitation
• Phase: N/A
• Start date: April 1, 2023
• Est. completion date: September 29, 2024

Study information

• Verified date: October 2023
• Source: University of North Carolina, Chapel Hill
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical 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 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.

Recruitment information / eligibility

• Status: Enrolling by invitation
• Enrollment: 40
• Est. completion date: September 29, 2024
• Est. primary completion date: September 29, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• 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)

Exclusion Criteria:

• 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

Related Conditions & MeSH terms

• Firefighter
• High Intensity Interval Training

Intervention

Behavioral:
• Integrated Exercise Program
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.

Locations

Country	Name	City	State
United States	UNC Chapel Hill	Chapel Hill	North Carolina

Sponsors (2)

Lead Sponsor	Collaborator
University of North Carolina, Chapel Hill	National Institute for Occupational Safety and Health (NIOSH/CDC)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.	Within 14 months
Primary	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.	Week 7 (post-intervention)
Primary	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.	Week 7 (post-intervention)
Primary	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.	Week 7 (post-intervention)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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).	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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.	2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Secondary	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.	6 weeks (i.e., one of last 2 sessions)
Secondary	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.	2 weeks (i.e., beginning of intervention following train-the-trainer completion)
Secondary	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.	6 weeks (i.e., one of last 2 sessions)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)
Secondary	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.	Baseline (i.e., pre-intervention), 7 weeks (i.e., post-intervention)