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During the COVID-19 pandemic, telework best practices decreased in importance compared to the need for social distancing. It is important that ergonomics assessments for home office workstations are equally as effective as assessment for traditional offices to maintain teleworker wellbeing. The purpose of this case study is to compare a remote, picture-based, home office assessment to a traditional, in-person, office assessment for employees of one Canadian University. Intraclass Correlation Coefficients (ICCs) and Bland-Altman Analyses (BAAs) revealed that the two methods provide repeatable results, with good agreement. Feedback from the participants suggested that picture-based assessments were as effective as in-person assessments; but that picture-based assessments could be improved with video conferencing to discuss findings and ask follow-up questions. Participants found value in remote assessments and, while they preferred in-person assessments, picture-based assessments are suitable when needed as they allow for many assessments to be completed without violating social distancing restrictions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: This study assessed firefighters' physiological stress response to a live fire training evolution (LFTE)., Methods: Seventy-six ( n = 76) firefighters completed an LFTE. Salivary samples were collected pre-, immediately post, and 30-min post-LFTE and analyzed for α-amylase (AA), cortisol (CORT), and secretory immunoglobulin-A (SIgA)., Results: Concentrations of AA, CORT, and SIgA were elevated immediately post LFTE versus pre (P<0.001) and 30-min post (P<0.001). Cohen's d effect size comparing pre and immediately-post means were 0.83, 0.77, and 0.61 for AA, CORT, and SIgA and were 0.54, 0.44, and 0.69 for AA, CORT, and SIgA, comparing immediately-post and 30-min post, respectively., Conclusions: These data demonstrate the stress response and activation of the hypothalamic-pituitary-adrenal/sympathetic-adreno-medullar axis and immune system immediately after real-world firefighting operations. Future work is needed to understand the impact of elevated stress biomarkers on firefighter performance and disease risk., Competing Interests: Conflicts of interest: None declared., (Copyright © 2024 American College of Occupational and Environmental Medicine.)

Participation in a virtual reality based active shooter training drill (VR-ASD) has been shown to increase biomarkers of stress; however, the impact of caffeine consumption on this response has not been studied. Caffeine ingestion has been shown to have favorable effects on physical and cognitive performance among athletic and tactical occupations alike. This study examined the impact of caffeine ingestion on subjective and physiological markers of stress in response to a mental stress task (MST) which involved participation in a VR-ASD and cognitive challenge consisting of mental arithmetic and a Stroop challenge. Fifty-three subjects were randomly assigned either caffeine (n = 26) or placebo (n = 27) prior to being exposed to the MST. Saliva samples, heart rate (HR), and state-anxiety inventory (SAI) scales, were collected before and after exposure to the MST. Saliva was analyzed for α-amylase (sAA), secretory IgA (SIgA), and cortisol (sCORT) concentrations. The MST resulted in significant increases in sAA, SIgA, HR, and SAI. Immediately post MST, sAA concentrations were significantly higher following the caffeine treatment compared to placebo. These data demonstrate that caffeine consumption results in significantly greater sAA concentrations post MST. This study was pre-registered as a clinical trial ("Impact of supplements on stress markers": NCT05592561)., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023. Published by Elsevier Ltd.)

Background: Formylated peptide receptor (FPR)-1 is a G-coupled receptor that senses foreign bacterial and host-derived mitochondrial formylated peptides (FPs), leading to innate immune system activation., Aim: We sought to investigate the role of FPR1-mediated inflammation and its potential as a therapeutic target in inflammatory bowel disease (IBD)., Methods: We characterized FPR1 gene and protein expression in 8 human IBD (~1000 patients) datasets with analysis on disease subtype, mucosal inflammation, and drug response. We performed in vivo dextran-sulfate sodium (DSS) colitis in C57/BL6 FPR1 knockout mice. In ex vivo studies, we studied the role of mitochondrial FPs and pharmacological blockade of FPR1 using cyclosporin H in human peripheral blood neutrophils. Finally, we assess mitochondrial FPs as a potential mechanistic biomarker in the blood and stools of patients with IBD., Results: Detailed in silico analysis in human intestinal biopsies showed that FPR1 is highly expressed in IBD ( n  = 207 IBD vs 67 non-IBD controls, P  < .001), and highly correlated with gut inflammation in ulcerative colitis (UC) and Crohn's disease (CD) (both P  < .001). FPR1 receptor is predominantly expressed in leukocytes, and we showed significantly higher FPR1+ve neutrophils in inflamed gut tissue section in IBD (17 CD and 24 UC; both P  < .001). Further analysis in 6 independent IBD (data available under Gene Expression Omnibus accession numbers GSE59071, GSE206285, GSE73661, GSE16879, GSE92415, and GSE235970) showed an association with active gut inflammation and treatment resistance to infliximab, ustekinumab, and vedolizumab. FPR1 gene deletion is protective in murine DSS colitis with lower gut neutrophil inflammation. In the human ex vivo neutrophil system, mitochondrial FP, nicotinamide adenine dinucleotide dehydrogenase subunit-6 (ND6) is a potent activator of neutrophils resulting in higher CD62L shedding, CD63 expression, reactive oxygen species production, and chemotactic capacity; these effects are inhibited by cyclosporin H. We screened for mitochondrial ND6 in IBD ( n  = 54) using ELISA and detected ND6 in stools with median values of 2.2 gg/mL (interquartile range [IQR] 0.0-4.99; range 0-53.3) but not in blood. Stool ND6 levels, however, were not significantly correlated with paired stool calprotectin, C-reactive protein, and clinical IBD activity., Conclusions: Our data suggest that FPR1-mediated neutrophilic inflammation is a tractable target in IBD; however, further work is required to clarify the clinical utility of mitochondrial FPs as a potential mechanistic marker for future stratification., Competing Interests: None declared., (© The Author(s) 2024. Published by Oxford University Press on behalf of Crohn's & Colitis Foundation.)

Ingestion of L-theanine and L-tyrosine has been shown to reduce salivary stress biomarkers and improve aspects of cognitive performance in response to stress. However, there have been no studies to concurrently examine the impact of both L-theanine and L-tyrosine ingestion during a mental stress challenge (MSC) involving a brief cognitive challenge and a virtual reality based active shooter training drill. Thus, the purpose of this study was to determine the impact of ingestion of L-theanine and L-tyrosine on markers of stress and cognitive performance in response to a virtual reality active shooter drill and cognitive challenge. The cognitive challenge involved a Stroop challenge and mental arithmetic. Eighty subjects (age = 21 ± 2.6 yrs; male = 46; female = 34) were randomly assigned L-tyrosine (n = 28; 2000 mg), L-theanine (n = 25; 200 mg), or placebo (n = 27) prior to MSC exposure. Saliva samples, state-anxiety inventory (SAI) scales, and heart rate (HR) were collected before and after exposure to the MSC. Saliva was analyzed for stress markers α-amylase (sAA) and secretory immunoglobulin A (SIgA). The MSC resulted in significant increases in sAA, SIgA, HR, and SAI. Ingestion of L-theanine and L-tyrosine did not impact markers of stress. However, the L-tyrosine treatment demonstrated significantly lower missed responses compared to the placebo treatment group during the Stroop challenge. These data demonstrate that ingestion of L-theanine or L-tyrosine does not impact markers of stress in response to a MSC but may impact cognitive performance. This study was pre-registered as a clinical trial ("Impact of supplements on stress markers": NCT05592561).

Objectives: Time-restricted eating (TRE) is a dietary intervention that may offer some protection against cardiovascular disease (CVD), while also preserving performance in athletes. To date however, research on TRE in an active population has only been conducted in college-age cohorts and the effects of TRE in an older, trained population are less understood. Therefore, the aim of this study was to compare the effects of a 4-wk, 16:8 TRE intervention on markers of CVD risk in middle-age, male cyclists., Methods: Participants (N = 12; age, 51.9 ± 8.6 y; training duration/wk, 375 ± 140 min; peak aerobic capacity, 41.8 ± 5.6 mL/kg/min) reported to the laboratory for two sessions (i.e., at baseline and post-TRE) where blood was drawn from an antecubital vein after an 8-h overnight fast. Dependent variables measured at baseline and post-TRE included insulin, cortisol, brain-derived neurotropic factor, free testosterone, thyroxine, triiodothyronine, C-reactive protein, advanced oxidative protein products, glutathione, tumor necrosis factor (TNF)-α, glucose, and a full lipid profile., Results: Compared with baseline, TRE significantly lowered TNF-α (12.3 ± 3.4 versus 9.2 ± 2.4 pg/mL; P = 0.02) and glucose concentrations (93.4 ± 9.7 versus 87.5 ± 7.9 mg/dL; P = 0.01), as well as significantly elevated high-density lipoprotein cholesterol levels (45.7 ± 13.7 versus 49.2 ± 12.3 mg/dL; P = 0.04), respectively. No further significant changes were observed between the remaining variables (all P > 0.05)., Conclusion: Overall, these data suggest that incorporating a 4-wk TRE intervention with habitual endurance training can significantly improve some markers of CVD risk and may compliment the robust health benefits derived from a regular exercise regimen., Competing Interests: Declaration of Competing Interest None., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Tactical occupations regularly encounter life-threatening situations while on duty. Although these occupations are often trained to utilize slow breathing (SB) during intense stress, there is no evidence supporting the effects on markers of stress in response to a virtual reality active shooter training drill (VR-ASD). The purpose of the study was to determine the impact of acute SB on biomarkers of stress in response to a VR-ASD. Seventy-nine (n = 79) subjects performed either slow breathing method 1 (SB1), slow breathing method 2 (SB2), or normal breathing (control) for five minutes, both pre- and post-VR-ASD. Saliva samples were analyzed for stress markers, including α-amylase (sAA) and secretory immunoglobulin-A (SIgA). Both methods of SB resulted in significantly lower sAA concentrations at 5 ( p < 0.001) and 30 min post-VR-ASD (SB1: p = 0.008; SB2: p < 0.001) compared to the control. In the control condition, the sAA concentrations were significantly elevated 5 min post-VR-ASD ( p < 0.001) but did not change across time in SB1 or SB2 ( p > 0.05). Thus, both SB1 and SB2 reduced the sAA response and resulted in lower concentrations post-VR-ASD. This study was pre-registered as a clinical trial ("Impact of Breathing Interventions on Stress Markers"; NCT05825846).

Abstract: Waldman, HS, Bryant, AR, Parten, AL, Grozier, CD, and McAllister, MJ. Astaxanthin supplementation does not affect markers of muscle damage or inflammation after an exercise-induced muscle damage protocol in resistance-trained males. J Strength Cond Res 37(7): e413-e421, 2023-It is well documented that exercise-induced muscle damage (EIMD) decreases exercise performance by elevated inflammation and subjective discomfort. Due to its potent antioxidative properties, astaxanthin (AX) may serve as a potential dietary supplement strategy for mitigating delayed-onset muscle soreness (DOMS) and enhancing recovery and performance. This study aimed to investigate the effects of AX on markers of muscle damage, inflammation, DOMS, and anaerobic performance and substrate metabolism. Thirteen resistance-trained men (mean ± SD , age, 23.4 ± 2.1 years) completed a double-blind, counterbalanced, and crossover design with a 1-week washout period between 2, 4-week supplementation periods at 12 mg·d -1 of AX or placebo. After each supplementation period, subjects completed 2 trials, with trial 1 including a graded exercise test (GXT) and a 30-second Wingate and trial 2 including an EIMD protocol followed by the collection of fasting blood samples (pre-post) to measure creatine kinase, advanced oxidative protein products, C-reactive protein, interleukin-6, insulin, and cortisol. Astaxanthin supplementation had no statistical effects on markers of substrate metabolism during the GXT, Wingate variables, or markers of muscle damage, inflammation, or DOMS when compared with placebo (all p > 0.05). However, 4 weeks of AX supplementation did significantly lower oxygen consumption during the final stage of the GXT (12%, p = 0.02), as well as lowered systolic blood pressure (∼7%, p = 0.04), and significantly lowered baseline insulin values (∼24%, p = 0.05) when compared with placebo. Collectively, these data suggest that 4 weeks of AX supplementation at 12 mg·d -1 did not affect markers of muscle damage, inflammation, or DOMS after an EIMD protocol in a resistance-trained male cohort., (Copyright © 2022 National Strength and Conditioning Association.)

Objective: This study examined the similarities in metabolic and physiological demands of a fire ground test (FGT) and a live fire training evolution., Methods: Twenty-seven firefighters completed either a FGT ( n = 13) or a live fire training evolution ( n = 14). Salivary samples were collected pre, immediately post, and 30-minutes post FGT and live fire training evolution, and analyzed for cortisol, uric acid, and interleukin-1β (IL-1β). Heart rate (HR) was measured pre- and post-task., Results: Both tasks resulted in significant elevations in cortisol, IL-1β, and HR., Conclusions: Both the FGT and live fire training evolution appear to result in similar metabolic and physiological demands. Further work may expand upon the additional elements (i.e., added heat) of the live fire training evolution. Fire departments may consider incorporating a variety of high intensity training to prepare personnel for these occupational demands.

Astaxanthin (AX) is an antioxidant which may spare endogenous carbohydrates and improve fat oxidation rates, thus improving metabolic flexibility. To date, no studies have attempted to examine the impact of AX in an overweight cohort, whom often suffer from metabolic inflexibility. Nineteen subjects (mean ± SD: age: 27.5 ± 6.3 years; height: 169.7 ± 9.0 cm; body mass: 96.4 ± 17.9 kg; BF%: 37.9 ± 7.0%; BMI: 33.4 ± 5.6 kg/m 2 ; VO 2peak : 25.9 ± 6.7 ml·kg -1 ·min -1 ) were recruited and supplemented with either 12 mg of AX or placebo (PLA) for 4 weeks. Subjects completed a graded exercise test on a cycling ergometer to examine changes in substrate oxidation rates. A total of 5 stages, each lasting 5 min and resistance increased 15 W each stage, were completed to examine changes in levels of glucose and lactate, fat and carbohydrate (CHO) oxidation rates, heart rate, and rating of perceived exertion (RPE). Although there were no changes found in rates of fat oxidation, blood lactate or glucose, or RPE (all p > 0.05), a significant decrease was observed in CHO oxidation from pre to post supplementation in the AX group only. Further, the AX group demonstrated a 7% decrease in heart rate across the graded exercise test. These findings suggest that 4 weeks of AX supplementation may offer some cardiometabolic benefits to overweight individuals, and be a favorable supplement for these individuals beginning an exercise program.

Objective: Firefighters are plagued with cardiometabolic disease (CMD). Obesity, poor cardiorespiratory and muscular fitness, and blood lipids (low-density lipoprotein cholesterol, triglycerides, low high-density lipoprotein cholesterol) are risk factors for CMD. However, markers of oxidative stress, inflammation, and insulin resistance can provide further insight regarding CMD risk., Methods: This study investigated the relationships between fitness metrics (cardiorespiratory and muscular fitness, percent body fat, waist circumference), blood lipids, blood pressure, and years of experience as a firefighter to blood markers of insulin resistance: Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), oxidative stress: advanced oxidation protein products (AOPPs), and inflammation: C-reactive protein., Results: Waist circumference and blood concentrations of triglycerides were significantly related to AOPPs and HOMA-IR. Cardiorespiratory fitness was inversely related to AOPPs, HOMA-IR and C-reactive protein., Conclusion: These findings demonstrate the importance of high cardiorespiratory fitness and low waist circumference to reduce markers of CMD., Competing Interests: Conflicts of interest: R.J.B. has received research funding from the following: USANA; Mannatech; Deerland Probiotics; Innovative Science Solutions; Nunn; CalerieHealth; Zycal Bioceuticals; Anklam Extrakt GmbH; Applied Food Sciences; DSE Healthcare; Compound Solutions; BAT; Resync, LLC; and Kaneka Nutrients. However, no funding was received from these agencies for this research study, and none of these agencies provided any assistance with the current research study in any way., (Copyright © 2022 American College of Occupational and Environmental Medicine.)

Background and Aims: Slow, deep breathing (SDB) lowers blood pressure (BP) though the underlying mechanisms are unknown. Redox improvements could facilitate hemodynamic adjustments with SDB though this has not been investigated. The purpose of this randomized, sham-controlled trial was to examine the acute effects of SDB on oxidative stress and endothelial function during a physiological perturbation (high-fat meal) known to induce oxidative stress., Methods and Results: Seventeen males (ages 18-35 years) were enrolled, and anthropometric measurements and 7-day physical activity monitoring were completed. Testing sessions consisted of 24-h diet recalls (ASA24), blood sample collection for superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS) analysis, and flow-mediated dilation (FMD). High-fat meals were ingested and 2-min breathing exercises (SDB or sham control breathing) were completed every 15 min during the 4-h postprandial phase. Blood sample collection and FMD were repeated 1-, 2-, and 4-h post meal consumption. Mean body mass index and step counts were 25.6 ± 4.3 kg/m 2 and 8165 ± 4405 steps per day, respectively. Systolic and diastolic BP and nutrient intake 24 h prior were similar between conditions. No time or time by condition interaction effects were observed for FMD. The total area under the curve (AUC) for SOD was significantly lower during SDB compared to the sham breathing condition (p < 0.01). No differences were observed in TBARS AUC (p = 0.538)., Conclusions: Findings from the current investigation suggest that SDB alters postprandial redox in the absence of changes in endothelial function in young, healthy males., Clinical Trial Registration Number: NCT04864184., Clinical Trials Identifier: NCT04864184., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.)

Betaine (BET) has shown to be effective in improving body composition and performance, although research in women is lacking. This study investigated the effects of BET supplementation on markers of metabolic flexibility, body composition, and anaerobic performance in college females. Twenty-three active subjects with 21.8 ± 3.0 years of age, 66.6 ± 8.8 kg body mass, 1.6 ± 0.1 m height, and 23.2 ± 5.3% body fat performed a graded exercise test on a cycle ergometer consisting of 4 incremental, 3 min stages for collection of fat and carbohydrate oxidation rates. Three 10 s sprint tests were then completed against a resistance of 7.5% of body mass, separated by 2.5 min of recovery. The study comprised 3 phases: (a) pre-supplementation, (b) randomization to supplement for 2-weeks with either 2.4 g/day BET or placebo (parallel design), and (c) post-supplementation. Repeated-measures analysis of variance were conducted to determine interactions or main effects. There were no group differences for substrate oxidation rates ( p  > 0.05). Although body composition improved pre-post for both groups ( p  < 0.05), only the BET group experienced a significant increase in fat free mass ( p  < 0.01; ∼3%). Further, only the BET group experienced improvements to performance such as a higher mean power output during the final sprint ( p  = 0.02; ∼3%) and a lower RPE during the final stage of the graded exercise test ( p  = 0.02). Results from this study suggest BET supplementation may improve body composition and some markers of performance during exercise in collegiate women.

Objective: High cardiorespiratory fitness (CRF) is associated with reduced markers of oxidative stress and cardiovascular disease (CVD) risk factors; however, this relationship has not been elucidated in firefighters. The purpose of this study was to examine differences in markers of CVD risk between firefighters who have either high or low levels of CRF., Methods: Forty-six firefighters participated in a maximal graded exercise test and a dual-energy x-ray absorptiometry scan and provided a fasted blood sample. V˙O 2max values were categorized based on American College of Sports Medicine guidelines to establish high- and low-fitness groups., Results: High fitness firefighters demonstrated significantly higher high-density lipoprotein cholesterol and lower markers of CVD risk: cholesterol, triglycerides, low-density lipoprotein cholesterol, insulin, homeostatic model assessment for insulin resistance, C-reactive protein, and advanced oxidation protein products concentrations., Conclusion: Firefighters are encouraged to maintain high CRF to reduce risk of CVD., Competing Interests: Conflict of interest: Richard J Bloomer has received research funding from the following: USANA; Mannatech; Deerland Probiotics; Innovative Science Solutions; Nunn; CalerieHealth; Zycal Bioceuticals; Anklam Extrakt GmbH; Applied Food Sciences. However, no funding was received from these agencies for this research study and none of these agencies provided any assistance with the current research study in any way., (Copyright © 2022 American College of Occupational and Environmental Medicine.)

Abstract: McAllister, MJ, Gonzalez, AE, and Waldman, HS. Impact of time restricted feeding on markers of cardiometabolic health and oxidative stress in resistance-trained firefighters. J Strength Cond Res 36(9): 2515-2522, 2022-Firefighters are often exposed to numerous occupational stressors that cause inflammation, oxidative stress (OS), and elevated risk for developing cardiometabolic disease. Time-restricted feeding (TRF) has been shown to result in favorable changes in markers of inflammation and cardiometabolic health. This study investigated the impact of a 6-week TRF intervention (14:10; fasting:feeding) in resistance-trained firefighters. Blood was analyzed for several markers of inflammation, OS, and cardiometabolic health: insulin, ghrelin, leptin, glucagon, adiponectin, resistin, advanced glycated end products (AGE), advanced oxidation protein products, total nitrite-nitrate levels, tumor necrosis factor-α, interleukin (IL)-6, IL-8, IL-10, as well as glucose and lipid levels. A graded exercise test was also conducted before and after the TRF intervention, and substrate oxidation rates were calculated and compared before and after the intervention. Comparisons pre and post TRF were determined with dependent t -tests. Time-restricted feeding resulted in significant reductions in advanced oxidation protein products (∼31%) and AGEs (∼25%); however, no other changes were found. These findings suggest that TRF may be a nutrition intervention aimed at improving some select markers of cardiometabolic health in firefighters, namely, by the reductions in advanced oxidation protein products and AGEs., (Copyright © 2020 National Strength and Conditioning Association.)

Abstract: McAllister, MJ, Steadman, KS, Renteria, LI, Case, MJ, Butawan, MB, Bloomer, RJ, and McCurdy, KW. Acute resistance exercise reduces postprandial lipemia and oxidative stress in resistance-trained men. J Strength Cond Res 36(8): 2139-2146, 2022-Acute ingestion of a high-fat meal (HFM) results in significant increases in postprandial triacylglycerols (TAG) and markers of oxidative stress (OS). Combined aerobic and resistance exercise can attenuate postprandial lipemia; however, it is not clear if acute resistance exercise alone can reduce postprandial OS. The purpose of this study was to determine if acute resistance exercise can attenuate postprandial OS and to compare the effects of moderate versus high-intensity resistance exercise in this regard. Nine ( n = 9) moderately resistance-trained individuals completed 3 testing conditions in a randomized order as follows: (a) rest (no exercise), (b) moderate intensity (3 sets of 10 repetitions at 68% 1 repetition maximum [RM]), and (c) high-intensity resistance exercise (4 sets of 6 repetitions at 85% 1RM). Exercises included barbell back squat, bench press, straight leg deadlift, lat pull-down, upright row, and sit-ups. A HFM was ingested 12 hours after each condition. Blood samples were collected immediately before as well as 2 and 4 hours after ingestion and analyzed for TAG, cholesterol (CHOL), insulin, malondialdehyde (MDA), total nitrate/nitrite (NOx), glutathione (GSH), and advanced oxidation protein products (AOPP). When comparing 4 hour area under curve (AUC) data between conditions, AOPP demonstrated a significantly lower AUC after the moderate-intensity condition compared with resting condition. In addition, resistance exercise resulted in significantly higher plasma NOx concentrations as well as lower TAG and CHOL concentrations after HFM ingestion. Resistance exercise also prevented a decline in GSH that was induced by the HFM. These results demonstrate that acute resistance exercise can attenuate postprandial OS., (Copyright © 2020 National Strength and Conditioning Association.)

Technological advancements have increased occupational flexibility for employees and employers alike. However, while effective telework requires planning, the COVID-19 pandemic required many employees to quickly shift to working from home without ensuring that the requirements for telework were in place. This study evaluated the transition to telework on university faculty and staff and investigated the effect of one's telework setup and ergonomics training on work-related discomfort in the at-home environment. Fifty-one percent of respondents reported increases in their existing discomfort while 24% reported new discomfort since working from home. These results suggest a need for ergonomic interventions including ergonomic training and individual ergonomic assessments for those who work from home., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This position stand aims to provide an evidence-based summary of the energy and nutritional demands of tactical athletes to promote optimal health and performance while keeping in mind the unique challenges faced due to work schedules, job demands, and austere environments. After a critical analysis of the literature, the following nutritional guidelines represent the position of the International Society of Sports Nutrition (ISSN)., General Recommendations: Nutritional considerations should include the provision and timing of adequate calories, macronutrients, and fluid to meet daily needs as well as strategic nutritional supplementation to improve physical, cognitive, and occupational performance outcomes; reduce risk of injury, obesity, and cardiometabolic disease; reduce the potential for a fatal mistake; and promote occupational readiness., Military Recommendations: Energy demands should be met by utilizing the Military Dietary Reference Intakes (MDRIs) established and codified in Army Regulation 40-25. Although research is somewhat limited, military personnel may also benefit from caffeine, creatine monohydrate, essential amino acids, protein, omega-3-fatty acids, beta-alanine, and L-tyrosine supplementation, especially during high-stress conditions., First Responder Recommendations: Specific energy needs are unknown and may vary depending on occupation-specific tasks. It is likely the general caloric intake and macronutrient guidelines for recreational athletes or the Acceptable Macronutrient Distribution Ranges for the general healthy adult population may benefit first responders. Strategies such as implementing wellness policies, setting up supportive food environments, encouraging healthier food systems, and using community resources to offer evidence-based nutrition classes are inexpensive and potentially meaningful ways to improve physical activity and diet habits. The following provides a more detailed overview of the literature and recommendations for these populations., Competing Interests: No potential conflict of interest was reported by the author(s)., (© 2022 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

The coronavirus SARS-CoV-2 contributes to morbidity and mortality mainly as a result of immune-pathology in the lungs. Recent data has shown multi-system involvement with widespread viral tropism. Here we present a detailed intestinal protein characterisation of SARS-Cov-2 entry molecules ACE2 and TMPRSS2 in patients with inflammatory bowel disease ([IBD]; ulcerative colitis [UC] and Crohn's disease [CD]) with age- and sex-matched non-IBD controls, and in those with fatal COVID-19 infection. In our dataset, ACE2 and TMPRSS2 displayed a membrane enterocyte staining in the ileum (due to presence of brush border/microvilli) in contrast to a cytoplasmic pattern in the colon. We also showed a high ACE2/low TMPRSS2 expression pattern in the ileum with a reverse trend in the colon. In UC, colonic ACE2 and TMPRSS2 are cytoplasmic in nature, with significantly higher ACE2 staining intensity compared to non-IBD controls. In inflamed and unaffected IBD mucosa, ileal and colonic enterocyte ACE2 and TMPRSS2 expressions are not modified in the histologic presence of inflammation. We observed immune cells within the lamina propria that expressed ACE2 and TMPRSS2, at higher frequencies in IBD when compared to non-IBD controls. These were identified as plasma cells with multiple myeloma oncogene 1/interferon regulatory factor 4 (MUM1/IRF4) expression. We further analysed the gut histology of six fatal COVID-19 cases, with no difference in colonic and ileal ACE2/TMRPSS2 staining (compared to non-IBD controls) and identified ACE2 + lamina propria plasma cells. Of interest, in this COVID-19 cohort, there was no histologic evidence gut inflammation despite known evidence of viral tropism within the enterocytes. Our data provides evidence for tissue expression of entry molecules ACE2 and TMPRSS2 including a close apposition to plasma cells - both pointing towards a role of the gut in the antecedent immune response to SARS-CoV-2 infection., (© 2021. The Author(s).)

Law enforcement personnel are required to respond to a variety of dangerous, potentially life-threatening high stress scenarios. Virtual reality (VR)-based training has been shown to attenuate stress responses; however, little is known about the acute stress response from VR exposure. This study examined the impact of participating in a VR-based active shooter training drill (ASD) on markers of physiological stress as well as potential differences in men and women. To examine the impact of participation in a ~50 sec VR-based ASD, 29 subjects (n = 29; 17 males, 12 females) participated in a quasi-experimental single group design. Saliva samples were collected and analyzed from 27 of the 29 subjects a total of four times 1) 30-min prior to, 2) 5-min prior to, 3) 5-min after, and 4) 30-min after the ASD and analyzed for α-amylase (AA) activity and concentrations of secretory immunoglobulin-A (SIgA), cortisol (CORT), and uric acid (UA). Participation in the ASD resulted in a significant ( p < 0.05) increase in salivary stress markers AA and SIgA. In addition, lower concentrations of CORT and UA were found in women compared to men. These findings have implications for law enforcement and/or military personnel that may seek to implement a VR-based training into their training regimen. Future studies should investigate the impact of longitudinal participation in ASD interventions to determine if this is an effective training method to reduce stress responses to real life active shooter training drills., (Copyright ©2022, Yale Journal of Biology and Medicine.)

Abstract: Waldman, HS, Bryant, AR, Shepherd, BD, Egan, B, and McAllister, MJ. No effect of a ketone monoester on markers of stress and performance in a live-burn search and rescue in firefighters. J Strength Cond Res 36(3): 763-771, 2022-Firefighters experience a range of stressors that impair performance and elevate the risk for developing cardiometabolic diseases. β-Hydroxybutyrate (βHB) has been shown to mitigate markers of oxidative stress and inflammation and serve as an alternative fuel with implications to physical performance. On 2 occasions in a double-blind, counterbalanced, and crossover design, 14 professional firefighters performed a live-burn, search and rescue (S&R) 30 minutes after ingestion of a ketone monoester (KME; 0.5 g·kg-1) or a placebo (PLA). Dependent variables collected before and after the S&R included salivary markers of stress and inflammation (cortisol, α-amylase, interleukin-1 beta, uric acid), perceptual markers (profile of mood state [POMS]), gastrointestinal distress (GI), rating of perceived exertion [RPE]), time to completion, and capillary blood measurement of βHB and glucose. KME resulted in capillary βHB concentrations of approximately 2.1-3.2 mM throughout the protocol. Capillary glucose concentrations were lower for the KME compared with PLA (∼7%) (interaction effect, p < 0.001). Salivary markers of stress, GI, and time to complete the S&R (∼10 minutes) did not differ between trials, although KME ingestion resulted in significantly higher RPE after the live-burn S&R (KME,6 ± 1; PLA, 4 ± 1). However, POMS data showed the KME also lowered subjective states of nervousness (KME, 0.0 ± 0.0; PLA, 0.6 ± 0.8) and anxiety (KME, 0.0 ± 0.0; PLA, 0.6 ± 0.7) before the S&R (all p < 0.05; large effect sizes). Compared with PLA, ingestion of a KME by firefighters did not mitigate the rise in various markers of salivary stress or impact physical performance during a live-burn S&R. However, differences in RPE and POMS variables were observed, suggesting a possible cognitive role for βHB., (Copyright © 2022 National Strength and Conditioning Association.)

This study investigated the effects of 6 mg/day of astaxanthin supplementation on markers of oxidative stress and substrate metabolism during a graded exercise test in active young men. A double-blind, randomized, counterbalanced, cross-over design was used. Fourteen men (age = 23 ± 2 years) supplemented with 6 mg/day of astaxanthin and a placebo for 4 weeks, with a 1 week washout period between treatments. Following each supplementation period, a fasting blood sample was obtained to measure markers of oxidative stress: glutathione, hydrogen peroxide, advanced oxidation protein products, and malondialdehyde. Participants also completed a graded exercise test after each treatment to determine substrate utilization during exercise at increasing levels of intensity. Glutathione was ∼7% higher following astaxanthin compared with placebo (1,233 ± 133 vs. 1,156 ± 185 μM, respectively; p = .02, d = 0.48). Plasma hydrogen peroxide and malondialdehyde were not different between treatments (p > .05). Although not statistically significant (p = .45), advanced oxidation protein products were reduced by ∼28%. During the graded exercise test, mean fat oxidation rates were not different between treatments (p > .05); however, fat oxidation decreased from 50 to 120 W (p < .001) and from 85 to 120 W (p = .004) in both conditions. Astaxanthin supplementation of 6 mg/day for 4 weeks increased whole blood levels of the antioxidant glutathione in active young men but did not affect oxidative stress markers or substrate utilization during exercise. Astaxanthin appears to be an effective agent to increase endogenous antioxidant status.

Gait adaptations, in response to novel environments, devices or changes to the body, can be driven by the continuous optimization of energy expenditure. However, whether energy optimization involves implicit processing (occurring automatically and with minimal cognitive attention), explicit processing (occurring consciously with an attention-demanding strategy) or both in combination remains unclear. Here, we used a dual-task paradigm to probe the contributions of implicit and explicit processes in energy optimization during walking. To create our primary energy optimization task, we used lower-limb exoskeletons to shift people's energetically optimal step frequency to frequencies lower than normally preferred. Our secondary task, designed to draw explicit attention from the optimization task, was an auditory tone discrimination task. We found that adding this secondary task did not prevent energy optimization during walking; participants in our dual-task experiment adapted their step frequency toward the optima by an amount and at a rate similar to participants in our previous single-task experiment. We also found that performance on the tone discrimination task did not worsen when participants were adapting toward energy optima; accuracy scores and reaction times remained unchanged when the exoskeleton altered the energy optimal gaits. Survey responses suggest that dual-task participants were largely unaware of the changes they made to their gait during adaptation, whereas single-task participants were more aware of their gait changes yet did not leverage this explicit awareness to improve gait adaptation. Collectively, our results suggest that energy optimization involves implicit processing, allowing attentional resources to be directed toward other cognitive and motor objectives during walking., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2021. Published by The Company of Biologists Ltd.)

The purpose of this investigation was to examine the importance of carbohydrate (CHO) timing while consuming a carbohydrate restricted diet (CRD) and completing a high-intensity exercise program. Eighteen males completed 6 weeks of training with the first 2 weeks serving as familiarization. During the final 4 weeks, subjects were randomized into 2 groups and completed 3 days of resistance training and 2 days of high-intensity interval training, while consuming a CRD (∼25%, ∼25%, and ∼50%, CHO, protein, and fat, respectively). The supplemented group ( n  = 9) ingested 30 g of CHO during exercise and 40 g of CHO immediately after each training session. The non-supplemented group ( n  = 9) consumed a non-caloric placebo during exercise. Pre- and post-testing measures included back squat and bench press 1-repetition maximums (1-RM), peak oxygen consumption ( V̇ O 2peak ), anaerobic power, body composition, fasted glucose, insulin, and total testosterone. Both groups significantly improved back squat and bench press 1-RM, V̇ O 2peak , and power output ( p  < 0.05), but there were no differences in blood markers or body composition. Our data suggests that CHO timing does not negatively impact training adaptations during a high-intensity exercise regimen when dietary CHO intake is restricted, but that favorable adaptations can be made while consuming a CRD. Novelty: Carbohydrate restricted dieting has no negative impact on resistance training adaptations. Short-term high-intensity interval training is effective in increasing peak oxygen consumption.

Objective: Firefighters are at a heightened risk for developing cardiovascular disease. The purpose of this study was to determine if time restricted feeding (TRF) can improve the stress/inflammatory response to a simulated firegrounds test (FGT) in professional firefighters., Methods: Thirteen firefighters participated in an 8-week TRF intervention (14:10 [fasting:feeding]) protocol and completed a FGT before and after the intervention. Blood lactate, heart rate, salivary C-reactive protein (CRP), interleukin-6 (IL-6), interleukin 1-β (IL-1β), and cortisol were measured pre and post FGT., Results: Following TRF, the salivary cortisol response to the FGT was significantly (P < 0.05) reduced. Salivary IL-6 and IL-1β were also significantly lower, and CRP was higher following the intervention., Conclusions: These findings demonstrate lower inflammation and reduced stress response to FGT following TRF and may suggest implications in terms of cardiometabolic benefits for firefighters., Competing Interests: Conflicts of interest: None declared., (Copyright © 2021 American College of Occupational and Environmental Medicine.)

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 , decreased (P < 0.05), and muscular strength, endurance, and power were not affected pre- versus post-intervention., Conclusion: Although , 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., Competing Interests: Conflict of Interest: None declared., (Copyright © 2021 American College of Occupational and Environmental Medicine.)

It has been well documented that police officers are frequently engaged in a variety of high stress situations during their normal daily tasks, such as civilian encounters where force is needed or domestic violence situations, that cause significant increases in a variety of physiological and psychological stress markers. Chronic exposure to stressors increases risk for cardiovascular disease (CVD) progression. The purpose of this study was to compare male and female salivary and blood markers of stress in response to an active shooter training drill (ASD) to determine if acute stress differentially impacts men and women to better understand if interventions should be targeted. Thirty-one participants (males ​= ​15 [mean age: 23], females ​= ​16 [mean age: 21]) participated in an ASD involving professional actors playing the role of one active gunman, as well as four victims. The ASD lasted approximately 50 seconds. Blood samples were collected 15 ​min prior as well as after the ASD and analyzed for epinephrine (EPI), norepinephrine (NE), and hydrogen peroxide (H 2 O 2 ) levels. Saliva samples were collected 30 and 5 ​min prior to the ASD and 5 and 30 ​min after the ASD, and were analyzed for cortisol, α-amylase, uric acid, and secretory immunoglobulin-A (SIgA). Our analysis revealed that acute (~50 ​sec) psychological stress in the form of an ASD resulted in significant increases in blood and salivary stress and oxidative stress markers in both men and women. However, four of the seven markers were lower in female participants (cortisol, uric acid, H 2 O 2 , and α-amylase presented significant main effects for sex). In addition, SIgA was significantly lower in women compared to men 30 ​min prior to, and five min post ASD. These findings suggest females may be at a lower risk to stress induced oxidative stress and CVD., Competing Interests: None., (© 2021 The Authors.)

Abstract: Krings, BM, Shepherd, BD, Swain, JC, Turner, AJ, Chander, H, Waldman, HS, McAllister, MJ, Knight, AC, and Smith, JW. Impact of fat grip attachments on muscular strength and neuromuscular activation during resistance exercise. J Strength Cond Res 35(2S): S152-S157, 2021-The purpose of this study was to examine the acute effects of Fat Gripz (FG) on muscular activation and strength. Resistance trained men (n = 15; age = 22.4 ± 2.3 years; mass = 83.2 ± 11.1 kg) performed 2 experimental trials in a randomized order. Subjects completed 1 repetition maximum (1RM) testing with an Olympic barbell (OB) and with FG attached to an OB during the exercises of deadlift, bent-over row, upright row, concentration curl, and completed maximum repetitions of pull-ups until failure. Surface electromyography (EMG) was used to measure muscle activity from 8 upper extremity muscles (trapezius, medial deltoid, biceps brachii, triceps brachii, flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris), while performing maximal voluntary isometric contractions during 1RM trials and while performing maximum number of pull-ups. When using the FG, 1RM strength was significantly decreased for each exercise, and the maximal number of pull-ups completed was significantly lower. Electromyography muscle activity was significantly increased in the forearm and shoulder muscles, but significantly decreased in the upper arm muscles with the use of FG during deadlift, bent-over row, and pull-ups. However, there were no differences for EMG activity for upright row and concentration curl. Differences in maximal strength, pull-up performance, and EMG activity with FG use may be due to the different muscle length positions. Although FG training may increase neuromuscular activation, decrements in muscular strength may result in prescribing low training loads that may not be ideal for building muscular strength., (Copyright © 2019 National Strength and Conditioning Association.)

High-stress occupations (ie, firefighters, military personnel, police officers, etc.) are often plagued by cardiometabolic diseases induced by exposure to chronic stressors. Interrupted sleep cycles, poor dietary patterns, lack of physical activity, and smoke exposure along with simultaneous psychological stressors promote chronic low-grade inflammation and excessive oxidative stress. Collectively, these data suggest that practical interventions which might mitigate the underlying pathologies of these cardiometabolic diseases are warranted. Ketones, specifically R -βHB, modulates intracellular signaling cascades such as the cellular redox ratios of NAD + /NADH, the activity of NAD dependent deacetylases SIRT1 and SIRT3, and promotes a robust mitochondrial environment which favors reductions in oxidative stress and inflammation. To date, the literature examining R -βHB as a signaling metabolite has mostly been performed from endogenous R -βHB production achieved through nutritional ketosis or cell culture and mouse models using exogenous R -βHB. To the authors knowledge, only 1 study has attempted to report on the effects of exogenous ketones and the mitigation of oxidative stress/inflammation. Therefore, the scope of this review is to detail the mechanisms of R -βHB as a signaling metabolite and the role that exogenous ketones might play in mitigating diseases in individuals serving in high-stress occupations., Competing Interests: Declaration of conflicting interests:The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2020.)

Background: Despite increases in diagnostics and effective treatments, over 300,000 men die from prostate cancer highlighting the need for specific and differentiating biomarkers. AR phosphorylation associates with castrate-resistance, with pAR ser213 promoting transcriptional activity. We hypothesise that combined pAR ser81 and pAR ser213 reduces survival and would benefit from dual-targeting androgen-dependent and Akt-driven disease., Methods: Immunohistochemistry and immunofluorescence were performed on matched hormone-naive and castrate-resistant prostate cancer samples. TempO-Seq gene profiling was analysed using DESeq2 package. LNCaP-AI cells were stimulated with DHT or EGF. WST-1 assays were performed to determine effects of Enzalutamide and BKM120 on cell viability., Results: Following the development of castrate-resistance, pAR ser81 expression reduced and pAR ser213 expression increased. Castrate-resistance pAR ser81 expression was not associated with survival but high pAR ser213 expression was associated with reduced survival from relapse. Combined high pAR ser81 and pAR ser213 was associated with reduced survival from relapse. pAR ser81 expression was induced by 10 nM DHT or 10 nM EGF and pAR ser213 expression was induced by treatment with 10 nM EGF in LNCaP-AI cells. Cell viability was reduced following treatment with 10 nM Enzalutamide and 10 nM BKM120. Eight genes were differentially expressed between hormone-naive and castrate-resistant tumours and twenty-five genes were differentially expressed between castrate-resistant tumours with high and low pAR ser213 expression., Conclusion: Combined pAR ser81 and pAR ser213 provides a novel prognostic biomarker for castrate-resistant disease and a potential predictive and therapeutic target for prostate cancer. Further studies will be required to investigate the combined effects of targeting AR and PI3K/AKT signalling.

Waldman, HS, Smith, JW, Lamberth, J, Fountain, BJ, Bloomer, RJ, Butawan, MB, and McAllister, MJ. A 28-day carbohydrate-restricted diet improves markers of cardiovascular disease in professional firefighters. J Strength Cond Res 34(10): 2785-2792, 2020-This study compared the effects of a 4-week, nonketogenic, carbohydrate-restricted (<25% of calories) diet (CRD) on markers of inflammation and oxidative stress in professional firefighters (FF). Subjects (n = 15) reported to the laboratory for 2 sessions (i.e., baseline and post-CRD) where blood was drawn from an antecubital vein after a 10-hour overnight fast. Dependent variables measured at baseline and post-CRD included adiponectin, insulin, human growth hormone, cortisol, C-reactive protein, albumin, lipids, glucose, amylase, creatine kinase, malondialdehyde (MDA), advance oxidation protein products (AOPP), total nitrate + nitrite, and soluble intracellular adhesion molecule-1. Compared with baseline, the CRD resulted in dramatic improvements to subjects' cardiometabolic profiles, including decreases in AOPP (51.3 ± 27.3 vs. 32.9 ± 7.9 ng·ml), MDA (1.6 ± 0.6 vs. 1.1 ± 0.5 µmol·L), and triglycerides (84.4 ± 34.4 vs. 64.2 ± 14.4 mg·dl), respectively. In addition, the CRD increased total cholesterol (151.5 ± 23.0 vs. 167.7 ± 38.2 mg·dl) and high-density lipoprotein cholesterol (46.3 ± 12.7 vs. 50.6 ± 15.5 mg·dl), but no differences were found with low-density lipoprotein cholesterol. Overall, our results show a 4-week CRD can favorably improve some markers of cardiovascular health in male FF.

Background: As the survival of castration-resistant prostate cancer (CRPC) remains poor, and the nuclear factor-κB (NF-κB) pathways play key roles in prostate cancer (PC) progression, several studies have focused on inhibiting the NF-κB pathway through generating inhibitory κB kinase subunit α (IKKα) small molecule inhibitors. However, the identification of prognostic markers able to discriminate which patients could benefit from IKKα inhibitors is urgently required. The present study investigated the prognostic value of IKKα, IKKα phosphorylated at serine 180 (p-IKKα S180) and threonine 23 (p-IKKα T23), and their relationship with the androgen receptor (AR) and Ki67 proliferation index to predict patient outcome., Methods: A cohort of 115 patients with hormone-naïve PC (HNPC) and CRPC specimens available were used to assess tumor cell expression of proteins within both the cytoplasm and the nucleus by immunohistochemistry. The expression levels were dichotomized (low vs high) to determine the associations between IKKα, AR, Ki67, and patients'Isurvival. In addition, an analysis was performed to assess potential IKKα associations with clinicopathological and inflammatory features, and potential IKKα correlations with other cancer pathways essential for CRPC growth., Results: High levels of cytoplasmic IKKα were associated with a higher cancer-specific survival in HNPC patients with low AR expression (hazards ratio [HR], 0.33; 95% confidence interval [CI] log-rank, 0.11-0.98; P = .04). Furthermore, nuclear IKKα (HR, 2.60; 95% CI, 1.27-5.33; P = .01) and cytoplasmic p-IKKα S180 (HR, 2.10; 95% CI, 1.17-3.76; P = .01) were associated with a lower time to death from recurrence in patients with CRPC. In addition, high IKKα expression was associated with high levels of T-cells (CD3+ P = .01 and CD8+ P = .03) in HNPC; however, under castration conditions, high IKKα expression was associated with high levels of CD68+ macrophages (P = .04), higher Gleason score (P = .01) and more prostate-specific antigen concentration (P = .03). Finally, we identified crosstalk between IKKα and members of the canonical NF-κB pathway in the nucleus of HNPC. Otherwise, IKKα phosphorylated by noncanonical NF-κB and Akt pathways correlated with members of the canonical NF-κB pathway in CRPC., Conclusion: The present study reports that patients with CRPC expressing high levels of nuclear IKKα or cytoplasmic p-IKKα S180, which associated with a lower time to death from recurrence, may benefit from IKKα inhibitors., (© 2020 The Authors. The Prostate published by Wiley Periodicals LLC.)

Police officers are frequently engaged in a variety of high-stress scenarios, such as high-speed chases and other suspect conflicts, that cause significant increases in a variety of physiological and psychological stress markers. The purpose of this study was to investigate salivary and blood markers of stress in response to an active shooter training drill (ASD). Thirty-one participants (n = 31; males = 15, females = 16; Age: 21 ± 3.5 years) participated in an ASD involving professional actors playing the role of one active gunman, as well as four victims. The ASD lasted approximately 50 s. Blood samples were collected 15 min prior as well as after the ASD and analyzed for epinephrine (EPI) and norepinephrine (NE) levels. Saliva samples were collected 30 and 5 min prior to the ASD and 5 and 30 min after the ASD, were analyzed for cortisol, α-amylase, and secretory immunoglobulin-A (SigA). The ASD resulted in significant ( p < 0.05) increases in EPI, α-amylase, and SigA levels. The increase in NE from pre to post ASD approached significance ( p = 0.06). These results demonstrate that a short duration (~50 s) ASD results in significant increases in both blood and salivary markers of stress. These data may provide meaningful implications for those engaged in high-stress tactical occupations, especially law enforcement and military personnel, as chronic exposure to such occupational stressors can contribute to cardiometabolic disease.

Factors such as shift work, poor diet, lack of physical activity, and irregular sleep patterns put men and women employed in high-stress occupations (e.g., firefighters, police officers) at risk for cardiometabolic diseases. Time-restricted feeding (TRF) is a new approach to combatting many of these diseases; it places an emphasis on when meals are consumed, rather than calorie content. By only manipulating the eating "window," and without changing the food composition of the diet, research in rodent models has shown promising results that have health implications in people, such as obesity prevention, improved insulin sensitivity, and decreased oxidative stress, inflammation, and cholesterol synthesis. Human trials remain limited and the current data are mixed with regard to TRF and improving health. Present findings suggest the timing of the feeding-fasting window, with feeding taking place in the waking hours and fasting in the evening hours, might offer the greatest benefit for improving cardiometabolic markers. Although additional human trials are needed, TRF might reset and synchronize metabolic "clocks" found throughout the body that are disturbed with obesity, shift work, and frequent eating. Therefore, TRF might offer an effective feeding-fasting paradigm with significant clinical implications for the management and treatment of cardiometabolic diseases observed in individuals in high-stress occupations in the United States and in the US population in general. This review outlines the current rodent and human evidence in these areas and the efficacy of TRF for improving human health., (© The Author(s) 2019. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Ingestion of ketone supplements, caffeine, and medium-chain triglycerides (MCTs) may all be effective strategies to increase blood levels of the ketone body beta-hydroxybutyrate (D-BHB). However, acute ingestion of a bolus of lipids may increase oxidative stress (OS). The purpose of the study was to investigate the impact of adding varying amounts of MCTs to coffee on blood levels of D-BHB and markers of OS. Ten college-aged men ingested coffee with 0, 28, and 42 g of MCT in a randomized order. Blood samples were collected pre- as well as 2 and 4 h postprandial and analyzed for D-BHB, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), glucose, triglycerides (TAG), insulin, and OS markers: advanced oxidation protein products (AOPP), glutathione (GSH), malondialdehyde (MDA), and hydrogen peroxide (H 2 O 2 ). All three treatments resulted in a significant increase in D-BHB, HDL-c, and TC as well as a significant decrease in TAG, MDA, H 2 O 2 , and insulin. The 42 g treatment was associated with significantly higher levels of AOPP and MDA. Acute ingestion of coffee results in favorable changes to markers of cardiometabolic health that were not impacted by the addition of 28 g of MCT. However, 42 g of MCT caused significantly greater OS.

Time-restricted feeding (TRF) has been shown to improve body composition, blood lipids, and reduce markers of inflammation and oxidative stress. However, most of these studies come from rodent models and small human samples, and it is not clear if the benefits are dependent upon a caloric deficit, or the time restriction nature of TRF. Based off of previous research, we hypothesized that humans following an ad libitum TRF protocol would reduce caloric intake and this caloric deficit would be associated with greater improvements in cardiometabolic health including blood pressure, body composition, blood lipids, and markers of inflammation and antioxidant status compared to an isocaloric TRF protocol. The purpose of this study was to: (1) examine the impact of TRF on markers of cardio-metabolic health and antioxidant status and (2) determine if the adaptations from TRF would differ under ad libitum compared to isocaloric conditions. Twenty-three healthy men were randomized to either an ad libitum or isocaloric 16:8 (fasting: feeding) TRF protocol. A total of 22 men completed the 28-day TRF protocol (mean ± SD; age: 22 ± 2.5 yrs.; height: 178.4 ± 6.9 cm; weight: 90.3 ± 24 kg; BMI: 28.5 ± 8.3 kg/m 2 ). Fasting blood samples were analyzed for glucose, lipids, as well as adiponectin, human growth hormone, insulin, cortisol, C-reactive protein, superoxide dismutase, total nitrate/nitrite, and glutathione. Time-restricted feeding in both groups was associated with significant (P < .05) reductions in body fat, blood pressure, and significant increases in adiponectin and HDL-c. No changes in caloric intake were detected. In summary, the results from this pilot study in metabolically healthy, active young men, suggest that TRF can improve markers of cardiometabolic health., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In the present study, our team aimed to investigate the effects of acute ingestion of a ketone salt (KS) supplement on the cognitive performance in healthy college-aged males during a dual-stress challenge (DSC). Following a peak oxygen uptake test and DSC familiarization, 16 males completed a DSC while cycling at 60% of their respective peak oxygen uptake after ingesting either a commercially available racemic (D- and L-)β-hydroxybutyrate (β-OHB) KS (0.38 g/kg body mass) or a placebo, using a triple-blinded, crossover, and counterbalanced design. The participants consumed the KS or placebo at -60 and -15 min prior to the start of the DSC. Heart rate, rating of perceived exertion, and blood β-OHB and glucose were sampled throughout. The DSC consisted of a mental arithmetic challenge and a modified Stroop Color Word, which alternated every 2 min for 20 min. Upon completion of the DSC, responses for correct, incorrect, and no responses were recorded for the mental arithmetic challenge and Stroop Color Word. Blood β-OHB was elevated with KS by -15 min and remained so throughout (p < .001), peaking at 0.76 ± 0.32 mM. Blood glucose was lower with KS compared with the placebo at -15 and 10 min by 9% and 5%, respectively (both ps < .05). There were no differences between the treatments for heart rate, rating of perceived exertion, mental arithmetic challenge, or Stroop Color Word. Overall, this study suggests that KSs are not effective aids for enhancing cognitive performance during a DSC, which might partially be explained by the inability of currently available commercial KS supplements to elevate β-OHB blood concentrations above ∼1.0 mM.

Firefighters and military personnel are exposed to a variety of stressors. The combination of mental and physical stress (i.e., dual stress challenges [DSCs]) results in significant oxidative stress (OS), which may contribute to cardiometabolic dysfunction. Curcumin (CUR) is an exogenous antioxidant that may attenuate such OS. Fourteen trained men participated in a randomized, cross-over design to investigate the impact of CUR on markers of OS resulting from DSC. CUR or placebo was ingested three days prior to, and the morning of, testing. The DSC involved 20 min of mental stress challenges during 35 min of cycling at 60% V̇O 2 peak . Blood was sampled before, as well as immediately, 30 min, and 60 min after, exercise and analyzed for glutathione (GSH), superoxide dismutase (SOD), hydrogen peroxide (H 2 O 2 ), and advanced oxidation protein products (AOPP). There was no treatment effect for any variable. However, the DSC resulted in significant reductions in SOD, H 2 O 2 , and AOPP at 30 and 60 min after exercise. Previous studies have shown that DSC results in significant OS compared to exercise alone. However, these data suggest the DSC was associated with reductions in postexercise markers of OS. Antioxidant therapy is likely not needed in trained men exposed to DSC.

Carbohydrate mouth rinsing has been shown to enhance aerobic exercise performance, but there is limited research with resistance exercise (RE). Therefore, the purpose of this investigation was to examine the effects of carbohydrate mouth rinsing during a high-volume upper body RE protocol on performance, heart rate responses, ratings of perceived exertion, and felt arousal. Recreationally experienced resistance-trained males (N = 17, age: 21 ± 1 years, height: 177.3 ± 5.2 cm, mass: 83.5 ± 9.3 kg) completed three experimental sessions, with the first serving as familiarization to the RE protocol. During the final two trials, the participants rinsed a 25-ml solution containing either a 6% carbohydrate solution or an artificially flavored placebo in a randomized, counterbalanced, and double-blinded fashion. The participants rinsed a total of nine times immediately before beginning the protocol and 20 s before repetitions to failure with the exercises bench press, bent-over row, incline bench press, close-grip row, hammer curls, skull crushers (all completed at 70% one-repetition maximum), push-ups, and pull-ups. Heart rate, ratings of perceived exertion, and felt arousal were measured at the baseline and immediately after each set of repetitions to failure. There were no differences for the total repetitions completed (carbohydrate = 203 ± 25 repetitions vs. placebo = 201 ± 23 repetitions, p = .46, Cohen's d = 0.10). No treatment differences were observed for heart rate, ratings of perceived exertion, or felt arousal (p > .05). Although carbohydrate mouth rinsing has been shown to be effective in increasing aerobic performance, the results from this investigation show no benefit in RE performance in resistance-trained males.

Waldman, HS, Smith, JW, Lamberth, J, Fountain, BJ, and McAllister, MJ. A 28-day carbohydrate-restricted diet improves markers of cardiometabolic health and performance in professional firefighters. J Strength Cond Res 33(12): 3284-3294, 2019-We investigated the effects of a 4-week ad-libitum, nonketogenic, carbohydrate-restricted (<25% of calories) diet (CRD) on cardiometabolic and performance markers in firefighters (FF). Subjects (n = 15) completed 9 sessions (trials 1-3 [familiarization], trials 4-6 [baseline], and trials 7-9 [post-CRD]). Following habitual western diet, anthropometric measures were assessed, glucose tolerance measured, and then completed a graded cycling test, maximal Wingate test, and conducted their FF physical performance assessment (FPPA) to measure performance while metabolic variables and perceptual responses were recorded. Subjects then adhered to a CRD for a 4-week duration and returned for repeat testing. Body fat as measured by BodPod, and 7-site skinfold thickness decreased (p < 0.01), and a decrease was observed in blood pressure (BP) (p < 0.01; ∼5 mm Hg) after CRD. There were no differences found for glucose tolerance, but an increase was found for fat oxidation rates (p < 0.01; ∼0.07 g·min) and a decrease in carbohydrate oxidation rates across a range of intensities (p < 0.01; ∼0.24 g·min). Finally, the 2.41-km run and pull-up performance during the FPPA improved (p < 0.01; ∼41 second and 3 repetitions, respectively) and with no differences observed between treatments regarding the Wingate test. To date, this is the first CRD implemented with FF and resulted in decreased fat mass (∼2.4 kg), BP, and improvements to performance on the FPPA while preserving high-intensity exercise. These data suggest that a 28-day CRD can benefit markers of health in professional FF without detriments to occupational performance.

Objective: To characterize changes in body positioning while performing a standardized slit lamp examination after exposure to an educational module on ergonomics., Design: Prospective interventional pilot study., Participants: Ten ophthalmology residents., Methods: An educational module discussing ergonomic issues in ophthalmology was created. In a standardized examination lane, participants were recorded performing 3 trials of an indirect slit lamp examination of a volunteer patient, adjusting equipment as they saw fit. Participants were then sent the module and within 2 weeks repeated the trial process. Data were processed using biomechanical software to obtain the Rapid Upper Limb Assessment (RULA) injury risk score, elbow and shoulder joint reaction moments, neck and trunk flexion angles, and spinal curvature magnitudes., Results: The RULA injury risk scores decreased after completion of the module (95% CI 2.10-2.77), indicating a lesser risk for injury to the resident. Shoulder flexion and elbow abduction moments also decreased (95% CI -3.2 to -1.5 and -0.44 to -0.04, respectively), suggesting a more neutral body posture. The trunk flexion angle increased after completion of the module (95% CI -5.1 to -1.6), signifying a more upright trunk posture; this was confirmed by the lumbar spine curvature, which flattened postmodule (95% CI 6.6-940)., Conclusions: These results suggest a promising ability for an educational module to mitigate some injury risk in this population during indirect slit lamp examination. It also delineated some awkward postures that persisted despite the module. These results will be reintegrated into the module to optimize its educational utility., (Copyright © 2018 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.)

Prostate cancer growth is controlled by androgen receptor signaling via both androgen-dependent and androgen-independent pathways. Furthermore, the prostate is an immune competent organ with inflammatory changes both within the systemic and local environment contributing to the reprogramming of the prostatic epithelium with consistently elevated lymphocyte infiltration and proinflammatory cytokines being found in prostate cancer. The crosstalk between the tumor microenvironment and androgen receptor signaling is complex with both protumorigenic and antitumorigenic roles observed. However, despite an increase in immune checkpoint inhibitors and inflammatory signaling blockades available for a range of cancer types, we are yet to see substantial progress in the treatment of prostate cancer. Therefore, this review aims to summarize the tumor microenvironment and its impact on androgen receptor signaling in prostate cancer., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: Those engaged in high stress occupations such as firefighters and military personnel are exposed to a variety of psychological and physiological stressors. The combination of mental and physical stress [i.e., dual stress challenges (DSC)] results in significant increases in stress hormones, which causes oxidative stress (OS) and contributes to elevated risk for cardiovascular disease. However, data are needed to determine the impact of DSC on markers of OS in exercise-trained individuals., Method: Fourteen healthy trained men aged 21-30 yrs. participated in a randomized, cross-over design to investigate the impact of DSC on blood markers of OS. The exercise alone condition (EA) consisted of 35 min of cycling at 60% V̇O 2 peak . The DSC involved 20 min of mental stress challenges during exercise. Blood was sampled before exercise, as well as immediately, and 30 and 60 min after exercise and analyzed for glutathione (GSH), superoxide dismutase (SOD), hydrogen peroxide (H 2 O 2 ) and advanced oxidation protein products (AOPP)., Result: No significant treatment × time interactions were found. No time effects were noted for SOD, or H 2 O 2 ; however, AOPP were reduced at 30 (p = .034) and 60 min post exercise (p = .006). GSH was reduced at 30 (p = .009) and 60 min post exercise (p = .031)., Conclusion: These results indicate the OS response from DSC is not greater than that produced from EA in exercise trained men. Future work should investigate the impact of chronic resistance and endurance exercise training on OS resulting from DSC., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Waldman, HS, Krings, BM, Basham, SA, Smith, JW, Fountain, BJ, and McAllister, MJ. Effects of a 15-day low carbohydrate, high-fat diet in resistance-trained men. J Strength Cond Res 32(11): 3103-3111, 2018-This study examined the effects of a 15-day isocaloric low carbohydrate (<25% E), high-fat (>50% E) (LCHF) diet on physiological and metabolic alterations in resistance-trained (RT) men. College-aged RT men (n = 11) completed 4 V[Combining Dot Above]O2max tests using treadmill every 5 days during the 15-day trial. Blood was drawn intravenously pre-exercise across each experimental trial for insulin, cortisol, and glucose. Pulmonary data were collected and substrate oxidation (OXI) was calculated during exercise. Body mass decreased (p < 0.04) with no further changes in anthropometric measures. Time to exhaustion was not affected across each day. Insulin dropped below baseline values (p < 0.0005). Cortisol increased from baseline to day 5 (p < 0.004) but returned back to near baseline at day 10, whereas glucose remained within normal range throughout the duration of the study. Carbohydrate (CHO) OXI dropped (p < 0.001) from baseline to day 5, and fat OXI increased from baseline to day 5 (p < 0.0001). Heart rate decreased from baseline to day 5 (p < 0.001) and again from day 10 to 15 (p < 0.02). Oxygen uptake (V[Combining Dot Above]O2) decreased from day 5 to 10 (p < 0.0001). A nonketo LCHF diet appears to favor RT men by altering metabolic markers without decrements in aerobic performance and be a potential diet intervention used by coaches. However, the reported cardiorespiratory responses should be interpreted reasonably because of the possibility the subjects running economy improved over experimental trials.

Objective: Firefighters (FFs) involved in fire suppression have the greatest on-duty risk of cardiovascular disease (CVD), which may be caused by oxidative stress (OS)., Methods: Healthy, active FFs performed a victim "search and clear" exercise involving three conditions: (1) no heat, (2) heat + antioxidant, and (3) heat + placebo. Blood samples were analyzed for OS markers glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), catalase (CAT), and advanced oxidation protein products (AOPP)., Results: Increased GSH was found during both heat conditions compared with no heat. CAT activity was higher immediately post exercise. AOPP was reduced post exercise., Conclusions: Antioxidant supplementation did not impact the OS response to exercise. Added heat did not cause OS and exercise resulted in reductions in OS markers. These findings can be attributed to the training status of the FFs involved.

This study examined the effects of a d-β-hydroxybutyrate (βHB) containing beverage on cognitive and performance measures during a bout of repeated Wingates. Fifteen healthy, college-aged males (mean ± SD; age: 23.1 ± 2.4 years, height: 165.4 ± 2.0 cm, mass: 81.4 ± 9.2 kg) volunteered for the present study. Trial 1 consisted of baseline measures and familiarization for the protocol. During trials 2 and 3, subjects reported to the laboratory, after a 10-h fast, and ingested 11.38 g of βHB or a placebo (PLA) beverage 30 min before exercise. Participants then completed a cognitive challenge (CC), consisting of a 5-min FitLight response task while cycling. At the cessation of the test, participants then completed four 15-s repeated Wingates with 4 min of rest between, followed by another 5-min CC response task. Blood ketones, glucose, and lactate were measured pre-CC and post-Wingates. βHB levels were significantly higher compared with PLA (0.53 vs. 0.21 mmol/L), respectively. A significant order effect was observed across trials 2 and 3 for total FitLight misses and hits, regardless of treatment. Further, there were no significant differences among Wingate power output between treatments, although fatigue index was higher in the βHB group compared with PLA (32.3 vs. 29.4 W/s), respectively. In conclusion, βHB did not improve high-intensity cycling or cognitive performance measures; however, these findings might be partially explained by the absolute dosing protocol used for βHB in the present study as opposed to a relative (g/kg) dosing protocol used in previous research.

Osteoarthritis (OA) was previously thought of as 'wear and tear' as humans age, however there is increasing evidence to support an inflammatory theory. The nucleotide-binding and oligomerization domain-like receptor containing protein 3 (NLRP3) inflammasome has been implicated in the pathogenesis of a number of arthritic disorders, producing proinflammatory cytokines and degradative enzymes such as Interleukin-1 beta (IL-1β), Tumour necrosis factor alpha (TNF-α) and Matrix metalloproteinase-3 (MMP-3) which drive cartilage degeneration and synovial inflammation. This review aims to summarise the evidence of NLRP3 involvement in OA. Currently, treatment options focus on management of the disease and to date there is no cure. The development of novel biomarkers for OA could improve diagnosis, treatment and management. Importantly, this review provides detail on the involvement of the NLRP3 inflammasome in OA pathology and how its members could act as potential biomarkers to assist clinical decisions., (Copyright © 2018 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

The purpose of this investigation was to examine the individual and combined effects of ingesting carbohydrates (CHO) and branched-chain amino acids (BCAA) during high-volume upper body resistance exercise (RE) on markers of catabolism and performance. Thirteen resistance-trained males completed 4 experimental trials with supplementation, ingesting beverages containing CHO, BCAA, CHO+BCAA, or placebo (PLA) in a randomized, double-blind design. The beverages were ingested in 118-mL servings 6 times during an ∼60-min RE session consisting of bench press, bent-over row, incline press, and close-grip row. Each RE was performed with 5 sets of repetitions at 65% 1-repetition maximum until volitional fatigue. Blood samples were collected at baseline, immediately postexercise, and 60 min postexercise to assess glucose and insulin. Cortisol was assessed immediately and at 60 min postexercise. No significant performance benefits were observed for any RE. CHO+BCAA (152.4 ± 71.4 ng/mL) resulted in the lowest cortisol levels, which was lower than BCAA and PLA (193.7 ± 88.5, 182.8 ± 67.5 ng/mL, p < 0.05), but not different from CHO (165 ± 76.5 ng/mL, p = 0.342). Postexercise insulin concentrations were significantly higher with CHO (4.79 ± 3.4 mU/L) compared with BCAA and PLA (3.7 ± 2.0, 3.5 ± 1.8 mU/L, p < 0.05), but not different from CHO+BCAA (4.3 ± 2.5 mU/L, p = 0.339). There was no treatment effect for glucose, but glucose significantly increased from baseline to immediately postexercise and significantly decreased at 60 min postexercise. Ingesting beverages containing CHO with or without BCAA during upper body resistance exercise may promote a more favorable postexercise less catabolic environment.

Objective: Investigations into the relationship between dietary carbohydrate restriction and health are mixed. Current guidelines for nutrition promote low-fat foods and higher carbohydrate consumption for optimal health and weight loss. However, high-fat, low-carbohydrate diets are revealing both intra- and extracellular adaptations that have been shown to elicit favorable cardiometabolic changes associated with obesity. Moreover, dietary fat is associated with higher satiety levels from the hormones adiponectin, leptin, and cholecystokinin. Additionally, insulin responses from high-glycemic carbohydrates are known to alter these pathways, potentially leading to an increase in energy consumption and a possible mechanism for obesity., Conclusion: There is convincing evidence of beneficial effects of controlled trials implementing high-fat, low-carbohydrate diets in both sedentary and obese individuals, but longer duration clinical trials are required to confirm this hypothesis., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Cummings, PM, Waldman, HS, Krings, BM, Smith, JW, and McAllister, MJ. Effects of fat grip training on muscular strength and driving performance in division I male golfers. J Strength Cond Res 32(1): 205-210, 2018-Fat grip (FG) training is implemented into strength and conditioning programs with the overall goal of increasing grip strength. Previous research assessing the effect of training with increased grip diameters compared with standard Olympic bar diameters has mainly been in acute settings. Therefore, the purpose of this study was to examine to effects FG training compared with normal diameter grip (CON) training during an 8-week periodized resistance training (RT) program in division I male golfers. Subjects (n = 10) were randomly assigned into 2 groups: the FG group (n = 5, scoring average: 75.4 ± 2.0) and CON group (n = 5, scoring average: 75.0 ± 0.5). Both groups participated in 8 weeks of RT (3 d·wk). The FG group completed every lift and repetition using FG, compared with the CON training group which used normal diameter bars. Pretraining and posttraining performance variables included swing speed, ball speed, driving distance, driving carry, maximum pull-ups to failure, right and left hand grip strength, and 1 repetition max trap-bar deadlift. The FG group demonstrated significant increases (p ≤ 0.05) in ball speed, carry, drive distance, and left hand grip strength after 8 weeks of RT. In a population, such as low-handicap division I male golfers, FG training may allow for athletes to increase golf-specific performance after 8 weeks of periodized RT. Strength and conditioning coaches may use FG training over the course of a training program with athletes who require adequate grip strength to further elicit training adaptations.