Oral Glutamine Supplement Reduces Subjective Fatigue Ratings during Repeated Bouts of Firefighting Simulations

Abstract

Wildland firefighting requires repetitive (e.g., consecutive work shifts) physical work in dangerous conditions (e.g., heat and pollution). Workers commonly enter these environments in a nonacclimated state, leading to fatigue and heightened injury risk. Strategies to improve tolerance to these stressors are lacking. Purpose: To determine if glutamine ingestion prior to and after consecutive days of firefighting simulations in the heat attenuates subjective ratings of fatigue, and evaluate if results were supported by glutamine-induced upregulation of biological stress responses. Methods: Participants (5 male, 3 female) ingested glutamine (0.15 g/kg/day) or a placebo before and after two consecutive days (separated by 24 h) of firefighter simulations in a heated chamber (35 °C, 35% humidity). Perceived fatigue and biological stress were measured pre-, post-, and 4 h postexercise in each trial. Results: Subjective fatigue was reduced pre-exercise on Day 2 in the glutamine group (p < 0.05). Peripheral mononuclear cell expression of heat shock protein 70 (HSP70) and serum antioxidants were elevated at 4 h postexercise on Day 1 in the glutamine trial (p < 0.05). Conclusions: Ingestion of glutamine before and after repeated firefighter simulations in the heat resulted in reduced subjective fatigue on Day 2, which may be a result of the upregulation of biological stress systems (antioxidants, HSPs). This response may support recovery and improve work performance.

The effect of intense physical activity session with glutamine supplementation on selected factors of wrestlers' immune system

“…Due to the fact that glutamine acts as an inhibitor of prostaglandins and is widely used by lymphocytes, there can be less reduction in lymphocytes in the complement group than in the placebo group at different stages Attributed to glutamine intake. The result is consistent with the results of Mary Moore [22], Banafsheh [18], KURU et al [23]. While the result of de Siqueira research [24] showed an increase in the number of lymphocytes after taking glutamine supplementation.…”

“…Because glutamine acts as an inhibitor of prostaglandins as well as an antioxidant and fuel for immune cells, these changes can be attributed to glutamine supplementation by the experimental group. This result is consistent with the results of Mary Moore, et al [22], Jann Harberts, et al [21]. While Banafsheh [18] reported that after taking glutamine supplementation, the percentage of neutrophils in the supplement group was significantly reduced compared to the control group.…”

Working hours, sleep, and fatigue in the public safety sector: A scoping review of the research

“…Among WFFs, two studies reported on ingestion of glutamine, an amino acid with anti‐inflammatory effects that may improve work performance. Both reported glutamine resulted in reduced subjective fatigue and improved physiologic response to heat stress compared with placebo during 2‐day firefighting simulations 89,93 . Another study demonstrated the feasibility of using wearable technology to collect typically difficult to obtain physiologic workload and productivity data from WFFs 96 .…”

“…Both reported glutamine resulted in reduced subjective fatigue and improved physiologic response to heat stress compared with placebo during 2-day firefighting simulations. 89,93 Another study demonstrated the feasibility of using wearable technology to collect typically difficult to obtain physiologic workload and productivity data from WFFs. 96 A simulation study demonstrated shortened travel distances were successful to reduce fatigue among a subgroup of WFFs (i.e., hotshot crew) who usually experience extensive travel and long work hours.…”

Can L‐glutamine augmented heat shock protein 70 expression prevent exercise‐induced exertional heat stroke and sudden cardiac death?

“…Specially, research is needed to investigate its pharmacokinetics and efficacy for guiding preventative practice before exercise in the heat, or ad-hoc medical treatment after exertional heatstroke or acute myocardial ischemia. A recent work has demonstratedHsp70 overexpression in firefighters as a result of oral glutamine ingestion (0.15 g/kg/day)11 ; further research is warranted to determine the dose-response relationship following acute and chronic supplementation. However, establishing the optimal dose of L-glutamine as a preventive measure will probably be difficult due to ethical issues and individual variability in thermotolerance or cardiac risks.…”