Effects of Beef-Forward Ready-to-Eat Meals on Recovery Following Simulated Fire Suppression Activities

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-blind, repeated-measures crossover design in healthy adult career firefighters. Participants will complete two experimental conditions separated by a 14- to 21-day washout period. The dietary conditions consist of beef-based protein RTEM and plant-based protein RTEM. The beef- 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 beef-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 condition 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.

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