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Objectives: Law enforcement agencies require minimum fitness standards to safeguard their officers and training staff. Firearms instructors (FI) are expected to maintain the same standards as their operational counterparts. This study aimed to quantify the daily physiological demands placed on FI. Methods: 19 FI (45 ± 5 years) completed occupational tasks whilst wearing heart rate (HR) monitors for a minimum 10 days. Maximal oxygen consumption (VO2max) testing was conducted on FI during a treadmill test (TT) and a multistage shuttle test (ST). Linear regression models were used to model the relationship between VO2 and HR throughout the TT. This model was applied to HR data from occupational tasks to infer oxygen consumption. Repeated Measures ANOVAs were used to compare time spent in VO2max equivalent zones throughout. Results: The VO2max achieved during ST (45.1 ± 5.6 ml/kg/min) was significantly higher than TT (39 ± 3 ml/kg/min) (p = 0.014). Time to exhaustion (TTE) was sooner on ST (06:26 min) compared to TT (13:16 min) (p <.001). FI spent ~85% of occupational time with an oxygen demand ≤20 ml/kg/min (p <.005). The most intense occupational tasks saw FI achieve VO2max ≥30 ml/kg/min, but <40 ml/kg/min. Conclusion: Using ST to assess cardiorespiratory fitness resulted in a quicker TTE and a higher VO2max. Predominantly, FI occupational tasks are low intensity with sporadic exposures requiring a VO2max of >40 ml/kg/min. To safeguard FI from occupational-related cardiorespiratory or long-term health issues, it is intuitive to suggest fitness standards should exceed a VO2max of 40 ml/kg/min. [ABSTRACT FROM AUTHOR]

Context: Cross-education (CE) refers to neuromuscular gains in the untrained limb upon contralateral limb training. To date, only laboratory-based exercise programs have demonstrated CE. Home-based exercise prescription eliciting CE could have greater clinical applicability. Objective: To determine the effect of an 8-week, home-based unilateral strength training intervention on isokinetic muscle strength, muscular excitation, and power in trained and untrained plantar flexors. Design: Randomized controlled trial. Methods: Thirty-four healthy participants were randomized to intervention (n = 20) or control (n = 14). The intervention group completed 3 sets of 12 repetitions of progressively loaded unilateral calf raises 3 days per week. Concentric and eccentric peak torque were measured using isokinetic dynamometry at 30°/s and 120°/s. Maximal electromyogram amplitude was simultaneously measured. Power was measured using a jump mat. All variables were measured at preintervention, midintervention, and postintervention. Results: Strength significantly increased bilaterally pre–post at both velocities concentrically and eccentrically in intervention group participants. Maximal electromyogram amplitude significantly increased pre–post bilaterally at both velocities in the medial gastrocnemii of the intervention group. Power significantly increased bilaterally pre–post in the intervention group, with a dose–response effect demonstrated in the untrained plantar flexors. The CE effects of strength, power, and electromyogram activation were 23.4%, 14.6%, and 25.3%, respectively. All control group values were unchanged pre–post. Conclusion: This study shows that a simple at-home unilateral plantar flexor exercise protocol induces significant increases in contralateral strength, muscular excitation, and power. These results suggest the applicability of CE in home rehabilitation programs aiming to restore or maintain neuromuscular function in inactive individuals or immobilized ankles. [ABSTRACT FROM AUTHOR]

Objectives. Musculoskeletal (MSK) complaints are prevalent in law enforcement officers (LEOs), but research that examines their risk factors is limited. This study aimed to identify the self-reported MSK complaint prevalence and perceived causes in LEOs. Methods. The Nordic musculoskeletal questionnaire was used to identify the 12-month and 7-day prevalence of MSK 'trouble' (ache, pain, discomfort) for nine body sites. The perceived cause, participant characteristics and occupational role were reported. Body fat percentage was measured using bioelectrical impedance. Results. Complete submissions of 186 questionnaires were received (80% male, median age 40.6 years, interquartile range 10.1). Eighty-six per cent of officers reported having an MSK complaint in the last 12 months, where lower back, shoulder and neck complaint prevalence was 59.1, 48.4 and 42.5%, respectively. The occupational role was associated with the site and presence of complaints (p < 0.05), where armed officers presented with more shoulder, lower back and hip/thigh complaints. Age, sex and body fat did not impact complaint prevalence. Participants mainly attributed their complaints to occupation equipment or to sport and exercise. Conclusion. MSK complaints were highly prevalent in this cohort, particularly armed officers. Further research is required to establish the impact of these complaints and how they can be mitigated. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effects of guarana supplementation on cognitive performance before and after a bout of maximal intensity cycling and to compare this to an equivalent caffeine dose. Twenty-five participants completed the randomised double-blind crossover trial by performing cognitive tests with one of three supplements, on three different days: guarana (125 mg/kg), caffeine (5 mg/kg) or placebo (65 mg/kg protein powder). After 30 min of rest, participants performed simple (SRT) and choice reaction time (CRT) tests, an immediate word recall test and Bond–Lader mood scale. This was followed by a cycling V̇ O2max test, and cognitive tests were then immediately repeated. Guarana supplementation decreased CRT before exercise (407 (sd 45) ms) in comparison with placebo (421 (sd 46) ms, P = 0·030) but not caffeine (417 (sd 42) ms). SRT after exercise decreased following guarana supplementation (306 (sd 28) ms) in comparison with placebo (323 (sd 32) ms, P = 0·003) but not caffeine (315 (sd 32) ms). Intra-individual variability on CRT significantly improved from before (111·4 (sd 60·5) ms) to after exercise (81·85 (sd 43·1) ms) following guarana supplementation, and no differences were observed for caffeine and placebo (P > 0·05). Alertness scores significantly improved following guarana supplementation (63·3 (sd 13·8)) in comparison with placebo (57·4 (sd 13·4), P = 0·014) but not caffeine (61·2 (sd 12·8)). There were no changes to V̇ O2max, immediate word recall or any other Bond–Lader mood scales. Guarana supplementation appears to impact several parameters of cognition. These results support the use of guarana supplementation to possibly maintain speed of attention immediately following a maximal intensity exercise test (V̇ O2max). [ABSTRACT FROM AUTHOR]

Introduction: Total Hip Arthroplasty (THA) is being increasingly undertaken in younger and more active patients, with many of these patients wanting to return to sport (RTS) after surgery. However, the percentage of patients RTS and time at which they are able to get back to sport following surgery remains unknown. The objective of this meta-analysis was to determine the time patients RTS after THA. Methods: A search was performed on PUBMED, MEDLINE, EMBASE, and the Cochrane Library for trials on THA and RTS, in the English language, published from the inception of the database to October 2020. All clinical trials reporting on to RTS following THA were included. Data relating to patient demographics, methodological quality, RTS, clinical outcomes and complications were recorded. The PRISMA guidelines were used to undertake this study. Results: The initial literature search identified 1720 studies. Of these, 11 studies with 2297 patients matched the inclusion criteria. 3 studies with 154 patients demonstrated an overall pooled proportion of 40.0% (95% CI, 32.5–47.9%) of patients RTS between 2 and 3 months after surgery. 4 studies with 242 patients demonstrated an overall pooled proportion of 76.9% (95% CI, 71.5–82.0) of patients RTS by 6 months after surgery. Pooled proportion analysis from 7 trials with 560 patients demonstrated 93.9% (95% CI, 82.7–99.5%) of patients RTS between 6 and 12 months after surgery. Conclusions: Pooled proportion analysis showed increasingly more patients were able to RTS after THA over the first 1 year after surgery. There remains marked inter and intra-study variations in time for RTS but the pooled analysis shows that over 90% of patients were able to RTS at 6–12 months after THA. These finding will enable more informed discussions between patients and healthcare professionals about time for RTS following THA. [ABSTRACT FROM AUTHOR]

Large cohort studies have reported that former professional football players have an increased risk of mortality from neurodegenerative disease. Due to emerging concerns regarding the safety of heading the technique is now banned for players under 12. The aim of this systematic review was to evaluate the association between heading exposure and cognitive function in professional football players. A search strategy was devised and entered into seven electronic databases: MEDLINE, Embase, Web of Science, PsycINFO, CENTRAL, SportDiscus and PEDro. The search identified 563 records. After screening records and applying the eligibility criteria, nine cross-sectional studies (n=925) were included in the review, investigating 452 current and 473 former players (859 males, 66 females). Six studies (n=595) reported evidence for an association between heading and impaired cognitive function, while three studies (n=330) reported no association. Diverse cognitive domains were investigated, which might underline the disparity in these results. The association between heading and cognitive function in professional football appears likely but remains inconclusive. Methodological heterogeneity and variability in the presentation of results limits the conclusions drawn. Prospective longitudinal studies using standardised methods, and including females, are required to provide evidence to support or refute an association., Competing Interests: The authors declare that they have no conflict of interest., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/).)