Skeletal muscle fitness and physiology as determinants of firefighter performance and safety: a narrative review.

Firefighters routinely perform tasks that are reliant on their muscular fitness, which includes muscular strength, power and endurance. Separately, firefighters can present with unique skeletal muscle physiology characteristics due to the strenuous nature of this occupation. This review aims to summarise muscular fitness and physiology as determinants of a firefighter's ability to perform occupation-specific tasks, identify the relevance of both muscular fitness and physiology to a firefighter's risk for sustaining a work-related injury, and address the contributions of muscular fitness and physiology on a firefighter's ability to recover from tasks and their readiness for performing subsequent or future tasks. The presented evidence reveals muscular fitness can determine a firefighter's capacity to perform their job effectively, while also influencing risk for occupational injury. Collectively, this review indicates exercise training emphasising improvements in muscular strength, power, and endurance (i.e. resistance training) should be encouraged in this occupation.

This review addressed muscular fitness and physiology in firefighters. Current evidence suggests firefighter task performance and risk for injury is associated with high levels of muscular fitness. Additionally, firefighters undergo unique changes in muscle morphology and physiology that can negatively affect the ability to safely perform occupation-specific tasks repeatedly.

Assessment of Frailty Among Older Adults in the Physical Activity Daily Trial.

Frailty is common among cardiac patients; however, frailty assessment data from patients with peripheral arterial disease (PAD) are limited. The purpose of this observational study was to identify the prevalence and factors related to frailty in addition to unique frailty marker groupings in a cohort of sedentary adults with PAD. We grouped three PAD-relevant frailty characteristics using Fried's frailty phenotype -1) exhaustion, (2) weakness, and (3) slowness-and observed the prevalence of pre-frailty (1-2 characteristics) and frailty (3 characteristics) in the PAD cohort. Of the 106 participants, 34.9% were robust/non-frail, 53.8% were pre-frail, and 2.8% were frail. Exhaustion (33.3%) was the most occurring characteristic followed by weakness (20.0%) and slowness (5.0%). The grouping of weakness + slowness (10.0%) was the most prevalent followed by exhaustion + weakness (8.3%) and exhaustion + slowness (5.0%). Among pre-frail participants, ankle brachial index was correlated with a reduction in gait speed.

Muscle Damage, Inflammation, and Muscular Performance following the Physical Ability Test in Professional Firefighters.

Proper monitoring of fatigue and muscular damage may be used to decrease the high levels of cardiovascular disease, overuse musculoskeletal injuries, and workers compensation claims within the profession of firefighting. The purpose of this study was to examine muscle damage, muscular fatigue, and inflammation responses following a typical firefighting shift. Twenty-four professional firefighters completed two Physical Ability Tests to standardize the tasks typically performed in a day of work, and to elicit similar physiological responses. Participants were then monitored for 48 h. Prior to, and 48 h following the Physical Ability Tests, participants were evaluated for changes in strength, power, range-of-motion, as well as blood markers including myoglobin and c-reactive protein. Following the Physical Ability Tests, significant differences in myoglobin (p < 0.05), grip strength (p < 0.05), vertical jump (p < 0.05), and sit-and-reach (p < 0.05) were observed. No difference in c-reactive protein was observed (p > 0.05). After 24 hours following a shift, firefighters exhibited decreased strength, power, and range-of-motion. This may lead to decreases in performance and an increased risk of injury.

Multiomics profiling of the impact of an angiotensin (1-7)-expressing probiotic combined with exercise training in aged male rats.

Angiotensin (1-7) [Ang (1-7)] is an active heptapeptide of the noncanonical arm of the renin-angiotensin system that modulates molecular signaling pathways associated with vascular and cellular inflammation, vasoconstriction, and fibrosis. Preclinical evidence suggests that Ang (1-7) is a promising therapeutic target that may ameliorate physical and cognitive function in late life. However, treatment pharmacodynamics limits its clinical applicability. Therefore, this study explored the underlying mechanisms altered by a genetically modified probiotic (GMP) that expresses Ang (1-7) combined with and without exercise training in an aging male rat model as a potential adjunct strategy to exercise training to counteract the decline of physical and cognitive function. We evaluated cross-tissue (prefrontal cortex, hippocampus, colon, liver, and skeletal muscle) multi-omics responses. After 12 wk of intervention, the 16S mRNA microbiome analysis revealed a main effect of probiotic treatment within- and between groups. The probiotic treatment enhanced α diversity (Inverse Simpson (F[2,56] = 4.44; P = 0.02); Shannon-Wiener (F[2,56] = 4.27; P = 0.02)) and ß-diversity (F[2,56] = 2.66; P = 0.01) among rats receiving our GMP. The analysis of microbes' composition revealed three genera altered by our GMP (Enterorhabdus, Muribaculaceae unclassified, and Faecalitalea). The mRNA multi-tissue data analysis showed that our combined intervention upregulated neuroremodeling pathways on prefrontal cortex (i.e., 140 genes), inflammation gene expression in the liver (i.e., 63 genes), and circadian rhythm signaling on skeletal muscle. Finally, the integrative network analysis detected different communities of tightly (|r| > 0.8 and P < 0.05) correlated metabolites, genera, and genes in these tissues.NEW & NOTEWORTHY This manuscript uses a multiomics approach (i.e., microbiome, metabolomics, and transcriptomics) to explore the underlying mechanisms driven by a genetically modified probiotic (GMP) designed to express angiotensin (1-7) combined with moderate exercise training in an aged male rat model. After 12 wk of intervention, our findings suggest that our GMP enhanced gut microbial diversity while exercise training altered the transcriptional response in relevant neuroremodeling genes, inflammation, and circadian rhythm signaling pathways in an aging animal model.

Preserving independence among under-resourced older adults in the Southeastern United States: existing barriers and potential strategies for research.

Disability prevention and preservation of independence is crucial for successful aging of older adults. To date, relatively little is known regarding disparities in independent aging in a disadvantaged older adult population despite widely recognized health disparities reported in other populations and disciplines. In the U.S., the Southeastern region also known as "the Deep South", is an economically and culturally unique region ravaged by pervasive health disparities - thus it is critical to evaluate barriers to independent aging in this region along with strategies to overcome these barriers. The objective of this narrative review is to highlight unique barriers to independent aging in the Deep South and to acknowledge gaps and potential strategies and opportunities to fill these gaps. We have synthesized findings of literature retrieved from searches of computerized databases and authoritative texts. Ultimately, this review aims to facilitate discussion and future research that will help to address the unique challenges to the preservation of independence among older adults in the Deep South region.

Whey protein improves glycemia during an oral glucose tolerance test compared to vigorous-intensity aerobic exercise in young adult men.

BACKGROUND: Both aerobic exercise and whey protein can improve glucose regulation. The purpose of this study was to investigate how a single bout of vigorous-intensity aerobic exercise and whey protein, independently, as well as when combined, influence glycemia during an oral glucose tolerance test in sedentary, young men. METHODS: Healthy males (n = 11) completed four randomized trials: no exercise/no whey protein (R); exercise (EX; walking at 70% VO2max for 60 min); 50 g of whey protein (W); and exercise combined with 50 g of whey protein (EXW). Each trial included a 75 g oral glucose tolerance test (OGTT) that was completed after an overnight fast. Blood samples were collected over a two-hour period during the OGTT. For EX and EXW, the exercise was performed the evening before the OGTT and the 50 g of whey protein was dissolved in 250 mL of water and was consumed as a preload 30 min prior to the OGTT. For R and EX, participants consumed 250 mL of water prior to the OGTT. Plasma samples were analyzed for glucose, insulin, C-peptide, glucagon, gastric inhibitory peptide (GIP) and glucagon like peptide 1 (GLP-1), and postprandial incremental area under the curve (iAUC) was calculated for each. RESULTS: Glucose iAUC was reduced during W (- 32.9 ± 22.3 mmol/L) compared to R (122.7 ± 29.8 mmol/L; p < 0.01) and EX (154.3 ± 29.2 mmol/L; p < 0.01). Similarly, glucose iAUC was reduced for EXW (17.4 ± 28.9 mmol/L) compared to R and EX (p < 0.01 for both). There were no differences in iAUC for insulin, C-peptide, GIP, GLP-1, and glucagon between the four trials. Insulin, C-peptide, glucagon, GIP, and GLP-1 were elevated during the whey protein preload period for W and EXW compared to EX and R (p < 0.01). There were no differences for insulin, C-peptide, glucagon, GIP, or GLP-1 between trials for the remaining duration of the OGTT. CONCLUSIONS: Glucose responses during an oral glucose tolerance test were improved for W compared to EX. There were no additional improvements in glucose responses when vigorous-intensity aerobic exercise was combined with whey protein (EXW).

Whey Protein Supplementation Improves the Glycemic Response and May Reduce Non-Alcoholic Fatty Liver Disease Related Biomarkers in Women with Polycystic Ovary Syndrome (PCOS).

Polycystic ovary syndrome (PCOS) increases type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) with insulin resistance. We hypothesized that a 35 g whey preload would improve insulin sensitivity and glucose handling while reducing biomarkers associated with NAFLD. Twenty-nine age-matched women (CON = 15, PCOS = 14) completed oral glycemic tolerance tests following baseline (Day 0) as well as an acute (Day 1) and short-term whey supplementation (Day 7). Whey had an interaction effect on glucose (p = 0.02) and insulin (p = 0.03), with glucose remaining stable and insulin increasing with whey supplementation. Insulin sensitivity (p < 0.01) improved with whey associated with increased glucagon secretion (p < 0.01). Alanine aminotransferase (ALT), and aspartate aminotransferase (AST) remained unchanged, but "day" had an effect on the AST:ALT ratio (p = 0.04), whereas triglycerides and sex hormone binding globulin overall were greater in the PCOS group (p < 0.05). Total cholesterol decreased in PCOS (by 13%) and CON (by 8%) (NS). HepG2 cells treated with plasma from participants before and after whey decreased lipid accumulation in the PCOS group after whey (p < 0.05). Whey provided an insulinogenic and glycemic homeostatic effect in women with PCOS with the potential to combat NAFLD-consequences.

Whey protein preload enhances the active GLP-1 response and reduces circulating glucose in women with polycystic ovarian syndrome.

Polycystic ovary syndrome (PCOS) increases risk for development of type 2 diabetes. Whey protein ingestion before a carbohydrate load attenuates blood glucose. For our exploratory, case-control study design, we hypothesized that 35 g whey protein isolate (WPI) preloading would increase postprandial incretins and reduce hyperglycemia in women with PCOS. Twenty-nine age-matched women (PCO = 14 and CON = 15) completed oral glycemic tolerance tests (OGTT) following baseline (Day 0) as well as 35 g WPI acute (Day 1) and short-term supplementation (Day 7). Eight venous samples were collected during each test for quantification of glucose, and enteropancreatic hormones and to calculate area under the curve (AUC). Data was analyzed via repeated measures ANCOVA with significance set at P< .05. "Day x time x group" significantly influenced glucose (P = .01) and insulin changes (P = .03). In both groups, AUCglu were significantly lower on Day 7 than Day 0 (P< .05). Postprandial glucose excursions were lower on Days 1 and 7 than Day 0 in PCO and CON. Both, PCO and CON exhibited greater insulin changes on Days 1 and 7 compared to Day 0 (P< .05). AUCglucagon were higher on Days 1 and 7 than on Day 0 (P< .05). Changes in active GLP-1 were higher on Day 1 than Day 0 (P= .03). Overall, we showed that WPI preloading augmented insulin release and consequently lowered circulating glucose in women with and without PCOS. This insulinogenic effect can be attributed to enhanced active GLP-1 levels. We concluded that the incretin-mimetic effect of WPI may aid women with PCOS in achieving glycemic homeostasis.

Changes in Health and Physical Fitness Parameters After Six Months of Group Exercise Training in Firefighters.

Proper training methods may be used as an effective preventative measure for many of the musculoskeletal injuries sustained as a first responder that are inherent to the profession. The traditionally low fitness levels and poor exercise habits of city firefighters may predispose this population to an increased risk of chronic conditions, such as cardiovascular and metabolic disease. The purpose of this study was to analyze changes in the health and fitness parameters of professional firefighters across North Texas during a six-month training program. Twenty-two professional firefighters completed six months of group training, consisting of two training sessions per week. These individuals underwent a pre- and post-fitness testing protocol that consisted of body composition, range of motion, anaerobic power, muscular endurance, and cardiorespiratory fitness. Improvements (p < 0.05) in flexibility, anaerobic performance, fatigue index, muscular endurance, and aerobic fitness were found following the six-month training program. No differences in body composition or peak power were observed (p > 0.05). Six months of group exercise improves aerobic and anaerobic fitness, exercise tolerance, muscular endurance, and flexibility in firefighters.