Impact of Time Restricted Feeding on Fitness Variables in Professional Resistance Trained Firefighters

Firefighters are at an elevated risk for cardiometabolic disease and sudden cardiac death due to physiological and psychological stressors. Research suggests time restricted feeding (TRF) may improve health and performance variables. Objective: This study investigated the effects of a 7-week TRF (14-hour fasting:10-hour eating window) on fitness variables related to physical health and performance among professional, resistance-trained firefighters. Methods: Several fitness variables were assessed pre- and post-TRF intervention. Results: Relative and absolute ventilatory threshold (VT) increased (P < 0.05), relative and absolute VO ₂peak decreased (P < 0.05), and muscular strength, endurance, and power were not affected pre- versus post-intervention. Conclusion: Although VO ₂peak decreased, all other performance variables were not negatively impacted by TRF. Improvements in VT may be associated with improvements to markers of endurance exercise performance in firefighters, but more data are needed to confirm this hypothesis.