The COVID-19 pandemic significantly altered much of US life with shifts to working-from-home and social distancing changing day-to-day behavior. We aimed to determine the self-reported prevalence of meeting US physical activity guidelines, stratified by sitting time during the early lockdown phase of COVID-19 in US adults. We conducted two cross-sectional internet-based studies April 3rd-May 4th, 2020 in convenience samples of US adults. Participants self-reported daily sitting time and weekly moderate-to-vigorous physical activity (MVPA) via questions from the International Physical Activity Questionnaire. A total of 5036 US adults (65.3% women, 30.2% with chronic conditions) provided complete physical activity and sitting time data (80.3% of total). Overall, 42.6% of participants reported sitting for > 8 h/day (95% CI: 41.2%–44.0%) and 72.5% (71.2%–73.7%) reported being either sufficiently (150–300 MVPA minutes) or highly active (>300 min). The greatest proportion of people self-reported being highly active and sitting for > 8 h/day (24.0%; 22.8%-25.2%), followed by being highly active and sitting for 6–8 h/day (20.9%; 19.8%–22.1%). Sitting and activity appeared similar between sexes, while there was evidence of some age differences. For example, more young adults (ages 18–34) appeared to self-report being inactive and more appeared to sit for > 8 h/day compared to older adults. High sitting time was reported by US adults (>40% sitting > 8 h/day) during April 2020. However, high levels of physical activity (>70% meeting guidelines) were also reported. Since physical activity cannot eliminate the negative health effects of sitting, maintaining activity and limiting sitting during periods of large workplace and societal shifts is encouraged.

Force plate assessments, such as countermovement jumps and isometric mid-thigh pulls, examine performances (e.g., jump height, force, power) and movement strategies (e.g., asymmetries, durations), and are best suited to characterize and monitor physical capabilities, not predict injuries. To begin applying force plate technologies, users must first; (1) develop a data management plan to visualize and capture data over time; (2) select appropriate force plates for their scenario; (3) design appropriate testing protocols to ensure valid and reliable data. Force plate assessments may be added to existing testing, serve as separate testing batteries for annual profile testing to compare individuals and understand initial physical capabilities, or for more frequent testing (i.e., monthly or weekly) to monitor training-related adaptations or neuromuscular fatigue. Although these assessments inform evidence-based program designs, human performance practitioners must understand the considerations for conducting appropriate force plate testing, as well as proper visualizations and management of force plate data. Thus, the aim of this review is to provide evidence-based practices for utilizing force plates in tactical populations (e.g., military, firefighters, police). This includes best practices to implement testing for performance profiling, training adaptations, and monitoring neuromuscular fatigue and force asymmetries. Of note, due to the large amount of force-time metrics to choose from, this article provides general examples of important metrics to monitor and training recommendations based on changes to these force-time metrics, followed by specific examples in three case studies.

Fyock-Martin, MB, Erickson, EK, Hautz, AH, Sell, KM, Turnbaugh, BL, Caswell, SV, and Martin, JR. What do firefighting ability tests tell us about firefighter physical fitness? A systematic review of the current evidence. J Strength Cond Res 34(7): 2093–2103, 2020—The firefighting profession is a physiologically demanding occupation. Currently, sudden cardiac deaths account for 40–50% of firefighter job-related deaths, for which, inadequate aerobic fitness (AF) and obesity are established as risk factors. Departments have instituted firefighting physical ability tests (FPATs) as a method of quantifying readiness for occupational-related demands. A systematic review of the current literature examining the correlation between field fitness test performance and FPAT completion times was performed. The search identified 5 studies that met the eligibility criteria. The total number of subjects in the 5 studies was 265 (259 men and 6 women), including 200 professional firefighters (75.5%), 40 volunteer (15.1%), 20 officers (7.5%), and 5 recruits (1.9%). Upper-body strength (UBs) and upper-body endurance (UBe) had the strongest correlation to FPATs (r = −0.31 to −0.66; R ² = 0.10 to 0.44 and r = −0.27 to −0.61; R ² = 0.07 to 0.37; p < 0.05, respectively). Two studies suggested that AF has a weak-to-moderate relationship with FPATs (r = 0.38 and r = −0.62). Two studies showed that anaerobic capacity had weak-to-strong correlations with FPATs (r = −0.40 and r = 0.79; R ² = 0.16 to 0.62; p < 0.05). No studies found a statistically significant correlation between lower-body strength and FPAT performance. Further research is needed to better understand the role of field-based fitness test results on FPAT performance. An annual department-driven multicomponent fitness assessment measuring UBs, UBe, anaerobic capacity, and AF is recommended based on the evidence reviewed.

Limited research exists comparing sex differences in muscular power. The primary purpose of this research was to determine if differences exist in power and velocity in the conventional deadlift (CDL). A secondary purpose was to examine the relationship among power, velocity, strength, and fat free mass (FFM). Eighteen strength trained athletes with ≥1 year CDL experience (women: n = 9, 29 ± 2 years, 162.3 ± 1.8 cm, 62 ± 2.4 kg, 23.3 ± 3.2 % body fat (%BF); men: n = 9, 29 ± 3 years, 175.6 ± 1.8 cm, 85.5 ± 1.4 kg, 14.8 ± 2.4 %BF), and ≥1.5 one repetition maximum (1-RM) CDL: body mass (BM) ratio (women: 1.6 ± 0.1 1-RM CDL: BM; men: 2.3 ± 0.1 1-RM CDL: BM), performed baseline (body composition, 1-RM CDL) and experimental sessions, in which velocity and power were measured at 30%, 60%, and 90% 1-RM. Repeated measures ANOVA and bivariate correlations were conducted. Men produced higher absolute average and peak power across all loads, but higher average velocity at only 30% 1-RM. When normalized to FFM, men produced higher peak and average power; however, women produced higher peak and average velocities across all loads. FFM and 1-RM were correlated with power. Greater power observed in men is driven by larger muscle mass, which contributes to greater strength.

Firefighting is a mentally and physically demanding profession which is compounded by poor sleep due to shift schedules commonly used by fire departments. Compared to other professions, firefighters are at high risk for musculoskeletal injuries, mental illnesses, and cardiovascular diseases. The purpose of this study was to systemically review the effects of sleep on firefighter occupational performance and health. A search was conducted for studies that conducted a quantitative analysis involving sleep and occupational performance in firefighters. Relevant data were extracted and study quality evaluated with Newcastle-Ottawa Scale. There were 15 articles meeting the inclusion criteria with a total sample of 1591 (1539 male, 52 female) firefighters. We found that firefighters with poor sleep measures had worse cognitive performance and overall health, but physical capabilities were not impacted by acute sleep restriction. However, chronic poor sleep would likely negatively impact physical performance due to being associated with a decline in numerous health measures. To avoid sleep-related declines in occupational performance fire departments should consider the consequences of shift schedules on the performance and health of firefighters. Furthermore, sleep education interventions, the use of wearables to monitor, recovery and sleep health screening appear beneficial based on prior research.