Effects of Pork Protein on Recovery Following Simulated Fireground Activity (PORK-FIRE)

Effects of Pork Protein Ingestion Before and Following Performing a Simulated Fire Ground Test on Markers of Catabolism, Inflammation, and Recovery

The goal of this clinical trial is to learn whether consuming pork-based protein before and after physically demanding simulated firefighting activities can improve recovery, physical performance, and cognitive performance in healthy adult firefighters. The study will also compare pork-based protein meals with plant-based protein meals and a carbohydrate-focused control condition.

The main questions this study aims to answer are:

Does consuming pork-based protein reduce changes in markers of muscle damage, physiological stress, and muscle soreness following a simulated fire ground test?

Does consuming pork-based protein help maintain or improve physical and cognitive performance during recovery compared with plant-based protein and a carbohydrate-focused control condition?

Researchers will compare three ready-to-eat meal conditions: pork-based protein, plant-based protein, and a carbohydrate-focused control condition. Each participant will complete all three conditions in a randomized crossover design, with 14 to 21 days between conditions.

Study Overview

• Status: Recruiting
• Conditions: Stress; Cognition; Muscle Damage; Exercise Recovery; Blood Biomarkers; Physical Performance Parameters
• Intervention / Treatment: Other: Pork-Based Protein Ready-to-Eat Meals; Other: Plant-Based Protein Ready-to-Eat Meals; Other: Carbohydrate-Focused Lower-Protein Ready-to-Eat Meals

Detailed Description

Firefighting is a physically and cognitively demanding occupation characterized by repeated exposure to strenuous activity, heat stress, heavy personal protective equipment, and time-sensitive occupational tasks. These demands can produce substantial physiological stress and fatigue that may influence recovery and readiness for subsequent occupational activities. Despite the importance of maintaining readiness between demanding events, relatively little is known about how short-term dietary strategies, particularly protein source and intake, influence recovery in career firefighters.

This study will examine the effects of short-term consumption of ready-to-eat meals (RTEM) differing in protein source and quantity on physiological recovery and occupational performance following strenuous simulated firefighting activity. The study uses a randomized, double-blinded, repeated-measures crossover design in healthy adult career firefighters. Participants will complete three experimental conditions separated by a 14- to 21-day washout period. The dietary conditions consist of pork-based protein RTEM, plant-based protein RTEM, and a carbohydrate-focused lower-protein control condition. The pork- and plant-based conditions are designed to provide comparable energy and macronutrient intake while allowing investigation of potential differences associated with protein source.

During each experimental condition, participants will complete a simulated fire ground test (FGT) consisting of nine occupationally relevant firefighting tasks while wearing personal protective equipment and a self-contained breathing apparatus. The FGT includes hose deployment and pulling, charged hose deployment, equipment carrying, a low-room search, forcible entry, ladder carrying, stair climbing and hose hoisting, ceiling breach activities, and a victim-dummy drag. Measures of FGT completion time, heart rate, air consumption, and work efficiency will be collected to characterize occupational performance and physiological demand.

Recovery will be evaluated before the simulated firefighting activity and during the subsequent recovery period. Assessments will characterize blood-based markers of catabolism, immune stress, muscle damage, and clinical safety, as well as muscle soreness, mood, cognitive function, vertical jump performance, and subsequent occupational performance.

The primary hypothesis is that the pork-based RTEM condition will attenuate catabolic responses, immune stress, muscle damage, soreness, and perceptions of fatigue following the FGT while supporting the maintenance or recovery of cognitive and physical performance. The inclusion of plant-based protein and carbohydrate-focused control conditions will help determine whether recovery responses differ according to dietary protein source and protein quantity.

The findings are intended to provide preliminary evidence regarding practical, food-based nutritional strategies that may support recovery and occupational readiness among firefighters following strenuous firefighting activity.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Drew Edward Gonzalez, PhD; Phone Number: 2107888616; Email: drewgonzalez418@shsu.edu

Study Locations

• United States
  • Texas
    • Fort Worth, Texas, United States, 76115
      • Recruiting
      • Bob Bolen Public Safety Complex Administration
      • Contact: Drew E Gonzalez, PhD; Phone Number: 2107888616; Email: drewgonzalez418@shsu.edu
      • Contact: Brain Newman, PhD; Phone Number: 360-393-5702; Email: Brian.Newman@fortworthtexas.gov
    • Huntsville, Texas, United States, 77340
      • Recruiting
      • Sam Houston State University
      • Contact: Drew E Gonzalez, PhD; Phone Number: 2107888616; Email: drewgonzalez418@shsu.edu
      • Sub-Investigator: Andrew Wolfe, EdD
      • Sub-Investigator: Nick Barringer, PhD
      • Sub-Investigator: Richard B Kreider, PhD
      • Sub-Investigator: Brian Newman, PhD
      • Sub-Investigator: Austin Graybeal, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 18 to 60 years of age
• Current trained male or female firefighter with the Fort Worth Fire Department
• Able to comply with all study procedures and the study timeline
• Willing to consume only the study-provided ready-to-eat meals (RTEM) during designated study periods
• Willing to refrain from alcohol, nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, and over-the-counter pain medications for 48 hours before testing sessions
• Available to complete the study visits and required testing procedures

Exclusion Criteria:

• Younger than 18 years or older than 60 years
• Not a current firefighter with the Fort Worth Fire Department
• Pregnant, breastfeeding, or planning to become pregnant during the study
• Orthopedic or musculoskeletal limitations that prevent safe completion of the vertical jump or simulated fire ground test
• Use of weight-loss dietary supplements or medications within the previous 2 weeks
• Unwilling to refrain from alcohol, NSAIDs, aspirin, or over-the-counter pain medications for 48 hours before testing sessions
• Unwilling or unable to consume only the study-provided RTEM during designated study periods
• Heavy smoking, defined as more than 1 pack of cigarettes per day during the previous 3 months
• Allergy to any of the protein sources or study foods

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Pork-Based Protein Ready-to-Eat Meals; Participants will consume pork-based protein ready-to-eat meals (RTEM) during this experimental condition. Meals will provide approximately 700.- 800 kcal, 80 g carbohydrate, 50 g protein, and 30 g fat per meal, with lean pork serving as the primary protein source. The dietary intervention is designed to provide a total daily protein intake consistent with study targets. Participants will consume the study-provided meals surrounding the simulated fire ground testing and recovery period, with physiological, cognitive, and physical performance outcomes assessed during recovery.	Other: Pork-Based Protein Ready-to-Eat Meals; Pork-Based Protein Ready-to-Eat Meals: Participants will consume study-provided ready-to-eat meals (RTEM) in which lean pork serves as the primary protein source. Meals are designed to provide approximately 700 - 800 kcal, 80 g carbohydrate, 50 g protein, and 30 g fat per meal, with total daily protein intake targeted at approximately 1.4-2.0 g/kg/day. Pork-based meals will be provided during the approximately 3-day experimental period surrounding the simulated fire ground test and subsequent recovery assessments. Meals are designed to match the energy and macronutrient content of the plant-based protein condition.
Active Comparator: Plant-Based Protein Ready-to-Eat Meals; Participants will consume plant-based protein ready-to-eat meals (RTEM) during this comparator condition. Meals will be designed to approximate the energy and macronutrient content of the pork-based condition, providing approximately 700-800 kcal, 80 g carbohydrate, 50 g protein, and 30 g fat per meal, with plant-based foods such as soy, tempeh, or tofu as the primary protein sources. Participants will consume the study-provided meals surrounding the simulated fire ground testing and recovery period, with the same physiological, cognitive, and physical performance outcomes assessed.	Other: Plant-Based Protein Ready-to-Eat Meals; Plant-Based Protein Ready-to-Eat Meals: Participants will consume study-provided ready-to-eat meals (RTEM) in which plant-based foods serve as the primary protein source. Plant protein sources may include soy, tempeh, tofu, and other soy-based foods. Meals are designed to provide approximately 700 - 800 kcal, 80 g carbohydrate, 50 g protein, and 30 g fat per meal, with total daily protein intake targeted at approximately 1.4-2.0 g/kg/day. Plant-based meals will be provided during the approximately 3-day experimental period surrounding the simulated fire ground test and subsequent recovery assessments and will be matched as closely as feasible to the pork-based condition for energy and macronutrient content.
Active Comparator: Carbohydrate-Focused Lower-Protein Control; Participants will consume carbohydrate-focused ready-to-eat meals during the control condition. This condition will provide a lower total daily protein intake of approximately 0.8 g/kg/day and will serve as a dietary control for comparison with the higher-protein pork-based and plant-based conditions. Participants will consume the study-provided meals surrounding the simulated fire ground testing and recovery period, with the same physiological, cognitive, and physical performance outcomes assessed.	Other: Carbohydrate-Focused Lower-Protein Ready-to-Eat Meals; Carbohydrate-Focused Lower-Protein Ready-to-Eat Meals: Participants will consume study-provided carbohydrate-focused ready-to-eat meals (RTEM) designed to provide a lower total daily protein intake of approximately 0.8 g/kg/day. This condition serves as the lower-protein dietary control for comparison with the pork-based and plant-based higher-protein conditions. Meals will be provided during the approximately 3-day experimental period surrounding the simulated fire ground test and subsequent recovery assessments.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Testosterone and Cortisol	Serum testosterone and cortisol concentrations will be measured to characterize anabolic and catabolic hormonal responses following the simulated fire ground test. Changes in testosterone, cortisol, and the testosterone-to-cortisol ratio will be compared across dietary conditions.	Baseline, 24, 48, and 72 hours following the simulated fire ground test
Change in Serum Creatine Kinase	Serum creatine kinase (CK) concentration will be measured as a marker of muscle damage and recovery following the simulated fire ground test. Changes in CK will be compared across the pork-based protein, plant-based protein, and carbohydrate-focused lower-protein dietary conditions.	Baseline, 24, 48, and 72 hours following the simulated fire ground test
Change in Perceived Muscle Soreness	Participants will report perceived muscle soreness to characterize subjective recovery following the simulated fire ground test. Muscle soreness responses will be compared across dietary conditions.	Pre-fire ground test and 24, 48, and 72 hours of recovery
Fire Ground Test Completion Time	Total time required to complete the simulated fire ground test (FGT) will be recorded as a measure of occupational firefighting performance. The FGT consists of standardized firefighting-related tasks performed while wearing personal protective equipment and a self-contained breathing apparatus.	During each simulated fire ground test on Day 1 (baseline) and Day 4 (72 hour mark)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Complete Blood Count With Differential	A complete blood count (CBC) with differential will be assessed to characterize hematological responses and monitor clinical safety across the experimental conditions. Measures will include standard hematological indices and leukocyte differential components reported by the clinical laboratory.	Baseline, 24, 48, and 72 hours following the simulated fire ground test
Change in Comprehensive Metabolic Panel	A comprehensive metabolic panel (CMP) will be assessed to characterize metabolic responses and monitor clinical safety across the experimental conditions. Standard CMP components, including markers related to renal and hepatic function, electrolytes, glucose, and protein status, will be evaluated as reported by the clinical laboratory.	Baseline, 24, 48, and 72 hours following the simulated fire ground test
Food Satisfaction	Participants will report satisfaction with the study-provided ready-to-eat meals to characterize acceptability of each dietary condition.	At Baseline, 24, 48, and 72 hours
Heart Rate During the Fire Ground Test	Heart rate will be monitored during the simulated fire ground test to characterize cardiovascular demand during occupational firefighting activity.	During each simulated fire ground test on Day 1 (baseline) and Day 4 (72 hour mark)
Change in Vertical Jump Performance	Vertical jump performance will be assessed as an indicator of lower-body neuromuscular performance and recovery following the simulated fire ground test. Performance will be compared across dietary conditions.	Pre-fire ground test on Day 1 and Day 4

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency and Severity of Adverse Symptoms	Participants will report the frequency and severity of general symptoms or side effects associated with each dietary condition, including gastrointestinal distress, dizziness, and shortness of breath.	At Baseline, 24, 48, and 72 hours
Change in Profile of Mood States	The Profile of Mood States (POMS) questionnaire will be used to assess changes in mood state and perceived fatigue associated with the simulated fire ground test and subsequent recovery.	Pre-fire ground test and through 24, 48, and 72 hours of recovery
Change in Trail Making Test Performance	The Trail Making Test (TMT) will be used to assess cognitive performance during recovery from the simulated fire ground test. Performance will be compared across dietary conditions.	Pre-fire ground test and through 24, 48, and 72 hours of recovery
Change in Psychomotor Vigilance Test Performance	The Psychomotor Vigilance Test (PVT) will be used to assess sustained attention and reaction-time performance during recovery from the simulated fire ground test. Performance will be compared across dietary conditions.	Pre-fire ground test and through 24, 48, and 72 hours of recovery

Collaborators and Investigators

• Sponsor: Sam Houston State University
• Collaborators: National Pork Board
• Investigators: Principal Investigator: Drew E Gonzalez, PhD, Sam Houston State University

Publications and helpful links

General Publications

• Gonzalez DE, McAllister MJ, Waldman HS, Ferrando AA, Joyce J, Barringer ND, Dawes JJ, Kieffer AJ, Harvey T, Kerksick CM, Stout JR, Ziegenfuss TN, Zapp A, Tartar JL, Heileson JL, VanDusseldorp TA, Kalman DS, Campbell BI, Antonio J, Kreider RB. International society of sports nutrition position stand: tactical athlete nutrition. J Int Soc Sports Nutr. 2022 Jun 23;19(1):267-315. doi: 10.1080/15502783.2022.2086017. eCollection 2022.
• Ferrando AA, Wolfe RR, Hirsch KR, Church DD, Kviatkovsky SA, Roberts MD, Stout JR, Gonzalez DE, Sowinski RJ, Kreider RB, Kerksick CM, Burd NA, Pasiakos SM, Ormsbee MJ, Arent SM, Arciero PJ, Campbell BI, VanDusseldorp TA, Jager R, Willoughby DS, Kalman DS, Antonio J. International Society of Sports Nutrition Position Stand: Effects of essential amino acid supplementation on exercise and performance. J Int Soc Sports Nutr. 2023 Dec;20(1):2263409. doi: 10.1080/15502783.2023.2263409. Epub 2023 Oct 6.
• Gonzalez DE, Hines KE, Sowinski RJ, Estes L, Johnson SE, Chun J, Lee H, Leon S, Gil A, Ko J, Broeckel J, Barringer ND, Rasmussen CJ, Kreider RB. Effects of Pork Protein Ingestion Prior to and Following Performing the Army Combat Fitness Test on Markers of Catabolism, Inflammation, and Recovery. Nutrients. 2025 Jun 13;17(12):1995. doi: 10.3390/nu17121995.

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2026
• Primary Completion (Estimated): November 30, 2026
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: September 8, 2026
• First Submitted That Met QC Criteria: September 8, 2026
• First Posted (Actual): September 15, 2026

Study Record Updates

• Last Update Posted (Actual): September 15, 2026
• Last Update Submitted That Met QC Criteria: September 8, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Exercise Recovery; Dietary Protein; Occupational Performance; Firefighters; Cognitive Performance; Muscle Soreness; Tactical Athletes; Pork Protein; Ready-to-Eat Meals; Fireground Test
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Diseases; Musculoskeletal Pain; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Myalgia
• Other Study ID Numbers: IRB-2025-396; NPB PR-006290 (Other Grant/Funding Number: NATIONAL PORK BOARD)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Individual participant data (IPD) will not be made publicly available. Requests for de-identified participant-level data may be considered on a case-by-case basis following publication of the primary study findings. Interested researchers may contact the corresponding author to inquire about data availability. Any sharing of data will be contingent upon the nature and purpose of the request, protection of participant confidentiality, applicable informed consent provisions, and approval or authorization as required by Sam Houston State University, the Institutional Review Board, the funding agency, and/or other applicable agreements or policies. Accordingly, a final determination regarding IPD sharing has not been made at this time.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No