Effects of a 28-Day Carbohydrate-Restricted Diet on Metabolic and Performance Markers in Professional Firefighters

Authors

Andrew E. Gonzalez, Texas State UniversityFollow
Hunter S. Waldman, Mississippi State UniversityFollow
Matthew J. McAllister, Texas State UniversityFollow

Abstract

PURPOSE:Firefighters (FF) experience acute physiological and psychological stressors such as disturbed sleep patterns, frequent snacking, smoke exposure, and intense physical exertion, likely contributing to a significant risk for cardiovascular disease (CVD) and sudden cardiac death. Additionally, FF have high obesity prevalence rates and low cardiovascular fitness levels. Proper dietary and exercise regime interventions may decrease CVD risk. Carbohydrate-restricted diets (CRD) may benefit FF health through increased metabolic flexibility, decreased fat mass, and improved body composition, without negatively affecting the strength and aerobic performance. METHODS:Twenty-one healthy, male professional FF recruited from local fire departments underwent 9 testing sessions: Trials 1-3 were used as familiarizations, Trials 4-6 (15-days later) established a baseline, and Trials 7-9 were performed following a 28-day CRD. The 28-day CRD consisted of a carbohydrate (CHO) restricted (less than 25%/day), caloric ad-libitum diet protocol allowing flexibility and mimicking real-life eating patterns. FF Physical Performance Assessment (FPPA) variables (2.41-km run, pull-ups, push-ups, and sit-ups) were analyzed using dependent t-test. Additionally, substrate oxidation rates for fats and CHO (g·min^-1) were measured during Graded Exercise Testing (GXT) at 5 timepoints and analyzed using a 2 x 5 (Treatment x Timepoint) RMANOVA. RESULTS:A significant difference (pp< 0.05). CONCLUSION:The study’s purpose was to examine the effects of a 28-day CRD among FF. The diet increased fat oxidation, decreased CHO oxidation during GXT, and was associated with improved FPPA 2.41-km run time and pull-ups. FF following a CRD can significantly reduce their risk for CVD and improve on-duty performance.

Recommended Citation

Gonzalez, Andrew E.; Waldman, Hunter S.; and McAllister, Matthew J. (2019) "Effects of a 28-Day Carbohydrate-Restricted Diet on Metabolic and Performance Markers in Professional Firefighters," International Journal of Exercise Science: Conference Proceedings: Vol. 2: Iss. 11, Article 113.
Available at: https://digitalcommons.wku.edu/ijesab/vol2/iss11/113