Muscle Damage and Overreaching During Wildland Firefighter Critical Training

Area of Science:

• Exercise Physiology
• Occupational Health
• Sports Medicine

Background:

• Wildland firefighting is physically demanding, requiring high levels of physical fitness.
• Critical Training (CT) for wildland firefighters (WLFFs) is designed to simulate extreme conditions.
• Understanding the physiological impact of CT is crucial for firefighter health and performance.

Purpose of the Study:

• To investigate the physiological effects of wildland firefighter (WLFF) critical training (CT).
• To document changes in muscle damage markers and assess for acute overreaching in WLFFs during CT.

Main Methods:

• Twenty-one WLFFs (18 male, 3 female) participated in an 11-day CT.
• Daily measurements included upper-body (US) and lower-body (LS) muscle soreness, and body weight (BW).
• Blood samples (creatine kinase, lactate dehydrogenase, cortisol, testosterone) and skinfolds (body fat, lean body weight) were collected at specific intervals.

Main Results:

• Significant changes were observed in body fat (BF) and lean body weight (LBW) throughout the CT.
• Muscle soreness (US, LS), creatine kinase (CK), lactate dehydrogenase (LDH), cortisol, and the testosterone/cortisol ratio showed significant time-dependent effects (P < 0.05).

Conclusions:

• WLFF CT imposes substantial physiological stressors on participants.
• The training leads to muscle soreness, indicators of muscle damage, and potential physiological overreaching.
• These findings highlight the need for monitoring and managing the physiological demands placed on WLFFs during intensive training.