The Acute Effect of High-Intensity Resistance Training on Subsequent Firefighter Performance.

ABSTRACT: Mason, MR, Heebner, NR, Abt, JP, Bergstrom, HC, Shapiro, R, Langford, EL, and Abel, MG. The acute effect of high-intensity resistance training on subsequent firefighter performance. J Strength Cond Res 37(7): 1507-1514, 2023-High-intensity resistance training (HIRT) is commonly performed by structural firefighters on duty to enhance occupational readiness. However, exercise-induced fatigue may negatively impact subsequent occupational performance. Therefore, the purpose of this study was to assess the acute effect of HIRT on subsequent occupational physical ability in structural firefighters and to determine the time course of recovery. Seven resistance-trained male firefighters performed a timed maximal effort simulated fireground test (SFGT) in 3 randomized conditions: baseline (SFGT baseline ), 10 minutes post HIRT (SFGT 10min ), and 60 minutes post HIRT (SFGT 60min ). Work efficiency and air depletion were assessed during the SFGT. The timed HIRT session consisted of a standardized set of exercises using absolute training loads. Repeated measures analysis of variance and minimal difference (MD) analysis assessed group and individual effects between the conditions, respectively. The level of significance was set at p < 0.05. SFGT 10min completion time was greater than SFGT baseline (430 ± 137 vs. 297 ± 69 seconds, p < 0.01), with no difference between SFGT baseline and SFGT 60min (297 ± 69 vs. 326 ± 89 seconds, p = 0.08). The MD analysis indicated that all firefighters' SFGT 10min times exceeded the MD (±26.4 seconds) compared with SFGT baseline . However, 43% of firefighters still exceeded the MD at SFGT 60min . Air depletion during SFGT 10min was greater than that during SFGT baseline (2,786 ± 488 vs. 2,186 ± 276 lb·in -2 , p = 0.02), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). Work efficiency during SFGT 10min was 40% lower than that during SFGT baseline ( p < 0.01), with no difference between SFGT baseline and SFGT 60min ( p = 0.25). These findings indicate that an acute bout of HIRT decreases multiple descriptors of firefighters' occupational performance 10 minutes post exercise with varied responses at 60 minutes post exercise.

Changes in physical activity during the initial stages of the COVID-19 pandemic.

INTRODUCTION: The COVID-19 pandemic response limited access to many traditional forms of physical activity (PA). Purpose:To assess changes in objectively measured PAofUniversity staff during the initial stageofthe COVID-19 pandemic. METHODS: We implemented a repeated measures natural experiment design. PA data (walking distance, steps∙d#x2D;1, and Moderate#x2D;to#x2D;Vigorous PA (MVPA) time) from commercial grade triaxial accelerometers were collected from employees (N#x3D;625) of a large, public university in the southeast United States during the months of Jan#x2D;May in calendar years 2019 and 2020. RESULTS: Walking distance (6#x2D;9#x25;, p#x3C;0.001) and steps∙d#x2D;1(7#x2D;11#x25;, p#x3C;0.001) were lower during April and May 2020 compared to 2019. However, MVPA time was not significantly different among calendar years for the months of March#x2D;May. Steps∙d#x2D;1significantly decreased after WHO's worldwide pandemic declaration (10,348#xB1;171 v. 9551#xB1;156 steps∙d#x2D;1, p#x3C;0.001) and campus closure (10,100#xB1;160 v. 9,186#xB1;167 steps∙d#x2D;1, p#x3C;0.001). Conversely, steps∙d#x2D;1significantly increased after implementation of the state's "Healthy at Home" order (9,693#xB1;177 vs. 10,156#xB1;185 steps∙d#x2D;1, p#x3C;0.001). CONCLUSION: A decrease in daily steps, but not MVPA, suggests increased sedentary behavior, not reduced participation in exercise, during the early stages of the COVID#x2D;19 pandemic. Specific pandemic response policies may positively or negatively affect PA and sedentary behavior.

An Incentivized, Workplace Physical Activity Intervention Preferentially Increases Daily Steps in Inactive Employees.

Although physical activity (PA) is associated with decreased risk of chronic diseases, fewer than half of American adults meet the recommendations for daily PA, in part, due to large amounts of sedentary time in the workplace. PURPOSE: To determine the efficacy of an incentivized workplace PA intervention. DESIGN: Retrospective cohort design. SETTING: Large southeastern university. PARTICIPANTS: Of the 16 588 eligible employees working ≥8 h/wk, 6246 (37.6%) participated and 2206 (13.3%) were included in data analysis. INTERVENTION: Six-week PA intervention with tiered incentives (value: $10.50-$29.00). MEASURES: Steps/day measured via consumer-grade PA monitors for 1-week pre-, 6-weeks during, and 1-week postintervention. ANALYSIS: Participants were grouped by preintervention PA into 4 groups: <6000 (I); 6000 to 7999 (II); 8000 to 9999 (III); and ≥10 000 (IV) steps/d ( n = 481, 540, 485, and 700, respectively) in accordance with the tiered incentive schedule. Statistical comparisons were made by repeated-measures analysis of variance. RESULTS: During the intervention, participants achieving ≥10 000 steps/d increased by 60%. Groups I, II, and III significantly increased steps/day during the intervention (46%, 24%, and 11%, respectively), which was partially maintained in groups I and II 1-week postintervention. Group IV did not increase steps/day during the intervention and significantly decreased steps/day 1-week postintervention. The estimated cost per participant of this intervention increased with from group I ($55.41) to IV ($71.90). CONCLUSION: An incentivized, workplace PA intervention preferentially increases PA and is most cost-effective among university employees with low initial PA who may benefit substantially from increased levels of PA.