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Purpose: To examine the sex differences in performance and perceived fatigue during resistance training prescribed using traditional (TRA) and autoregulation rest-redistribution training (ARRT) approaches. Methods: Twelve resistance-trained men and 12 women completed 2 sessions including the bench-press exercise matched for load (75% of 1-repetition maximum), volume (24 repetitions), and total rest (240 s). Sessions were performed in a counterbalanced randomized design with TRA consisting of 3 sets of 8 repetitions with 120-second interset rest and ARRT employing a personalized combination of clusters, repetitions per cluster, and between-clusters rest regulated with a 20% velocity-loss threshold. The effects of TRA and ARRT on velocity loss, unilateral isometric peak force, and rating of fatigue (ROF) were compared between sexes. Results: The velocity loss was generally lower during ARRT compared with TRA (−0.47% [0.11%]), with velocity loss being mitigated by ARRT to a greater extent among males compared with females (−0.37% [0.15%]). A smaller unilateral isometric peak force decline was observed after ARRT than TRA among males compared with females (−38.4 [8.4] N). Lower ROF after ARRT than TRA was found among males compared to females (−1.97 [0.55] AU). Additionally, males reported greater ROF than females across both conditions (1.92 [0.53] AU), and ARRT resulted in lower ROF than TRA overall (−0.83 [0.39] AU). Conclusions: The ARRT approach resulted in decreased velocity loss, peak force impairment, and ROF compared with TRA in both sexes. However, male subjects exhibited more pronounced acute within-session benefits from the ARRT method. [ABSTRACT FROM AUTHOR]

Background: Physical activity has been associated with preventing the development of type 2 diabetes and atherosclerotic cardiovascular disease. However, our understanding of the precise molecular mechanisms underlying these effects remains incomplete and good biomarkers to objectively assess physical activity are lacking. Methods: We analyzed 3072 serum proteins in 26 men, normal weight or overweight, undergoing 12 weeks of a combined strength and endurance exercise intervention. We estimated insulin sensitivity with hyperinsulinemic euglycemic clamp, maximum oxygen uptake, muscle strength, and used MRI/MRS to evaluate body composition and organ fat depots. Muscle and subcutaneous adipose tissue biopsies were used for mRNA sequencing. Additional association analyses were performed in samples from up to 47,747 individuals in the UK Biobank, as well as using two-sample Mendelian randomization and mice models. Results: Following 12 weeks of exercise intervention, we observed significant changes in 283 serum proteins. Notably, 66 of these proteins were elevated in overweight men and positively associated with liver fat before the exercise regimen, but were normalized after exercise. Furthermore, for 19.7 and 12.1% of the exercise-responsive proteins, corresponding changes in mRNA expression levels in muscle and fat, respectively, were shown. The protein CD300LG displayed consistent alterations in blood, muscle, and fat. Serum CD300LG exhibited positive associations with insulin sensitivity, and to angiogenesis-related gene expression in both muscle and fat. Furthermore, serum CD300LG was positively associated with physical activity and negatively associated with glucose levels in the UK Biobank. In this sample, the association between serum CD300LG and physical activity was significantly stronger in men than in women. Mendelian randomization analysis suggested potential causal relationships between levels of serum CD300LG and fasting glucose, 2 hr glucose after an oral glucose tolerance test, and HbA1c. Additionally, Cd300lg responded to exercise in a mouse model, and we observed signs of impaired glucose tolerance in male, but not female, Cd300lg knockout mice. Conclusions: Our study identified several novel proteins in serum whose levels change in response to prolonged exercise and were significantly associated with body composition, liver fat, and glucose homeostasis. Serum CD300LG increased with physical activity and is a potential causal link to improved glucose levels. CD300LG may be a promising exercise biomarker and a therapeutic target in type 2 diabetes. [ABSTRACT FROM AUTHOR]

The relationship between sarcopenia and the long‐term risk of atrial fibrillation (AF) remains unclear. This study recruited a large prospective Caucasian cohort from the UK Biobank. Participants were assessed at baseline with handgrip strength and muscle mass and were categorized into groups of non‐sarcopenia, probable sarcopenia, and confirmed sarcopenia. Kaplan–Meier method and Cox proportional hazards model were used to explore the association between sarcopenia and the incidence of AF. The genetic predisposition of AF was assessed by polygenic risk score. Sensitivity analyses were performed to validate the results. A total of 384,433 participants with a median age of 58 years and 54.3% women were enrolled in this study. There were 24,007 cases of new‐onset AF over a median follow‐up of 12.56 years. The groups of non‐sarcopenia, probable sarcopenia, and confirmed sarcopenia accounted for 22,290 (6.1%), 1665 (9.2%), and 52 (11.9%) cases, respectively. Compared with the non‐sarcopenia group, participants with probable sarcopenia or confirmed sarcopenia had an 8% (95% CI, 1.03–1.14) or 61% (95% CI, 1.23–2.12) higher risk of AF incidence. The findings remained robust in multiple sensitivity analyses, such as subgroup analysis and further adjustment of genetic predisposition. Notably, the association between sarcopenia and a high AF risk was more pronounced in younger participants, women, and those with valvular heart disease. In conclusion, sarcopenia was associated with a high long‐term risk of AF in Caucasians, supporting sarcopenia as a new independent risk factor of AF. [ABSTRACT FROM AUTHOR]

Highlights Insertions and deletions (indels) are the second most common type of variation in the human genome. However, limited data on their associations with exercise‐related phenotypes have been documented. The aim of the present study was to examine the association between 18,370 indel variants and power athlete status, followed by additional studies in 357,246 individuals. In the discovery phase, the D allele of the MDM4 gene rs35493922 I/D polymorphism was over‐represented in power athletes compared with control subjects (P = 7.8 × 10−9) and endurance athletes (P = 0.0012). These findings were replicated in independent cohorts, showing a higher D allele frequency in power athletes compared with control subjects (P = 0.016) and endurance athletes (P = 0.031). Furthermore, the D allele was positively associated (P = 0.0013) with greater fat‐free mass in the UK Biobank. MDM4 encodes a protein that inhibits the activity of p53, which induces muscle fibre atrophy. Accordingly, we found that MDM4 expression was significantly higher in the vastus lateralis of power athletes compared with endurance athletes (P = 0.0009) and was positively correlated with the percentage of fast‐twitch muscle fibres (P = 0.0062) and the relative area occupied by fast‐twitch muscle fibres (P = 0.0086). The association between MDM4 gene expression and an increased proportion of fast‐twitch muscle fibres was confirmed in two additional cohorts. Finally, we found that the MDM4 DD genotype was associated with increased MDM4 gene expression in vastus lateralis and greater cross‐sectional area of fast‐twitch muscle fibres. In conclusion, MDM4 is suggested to be a potential regulator of muscle fibre specification and size, with its indel variant being associated with power athlete status. What is the central question of this study? Which indel variants are functional and associated with sport‐ and exercise‐related traits? What is the main finding and its importance? Out of 18,370 tested indels, the MDM4 gene rs35493922 I/D polymorphism was found to be the functional variant (affecting gene expression) and the most significant, with the deletion allele showing associations with power athlete status, fat‐free mass and cross‐sectional area of fast‐twitch muscle fibres. Furthermore, the expression of MDM4 was positively correlated with the percentage of fast‐twitch muscle fibres and the relative area occupied by fast‐twitch muscle fibres. What is the central question of this study?Which indel variants are functional and associated with sport‐ and exercise‐related traits?What is the main finding and its importance?Out of 18,370 tested indels, the MDM4 gene rs35493922 I/D polymorphism was found to be the functional variant (affecting gene expression) and the most significant, with the deletion allele showing associations with power athlete status, fat‐free mass and cross‐sectional area of fast‐twitch muscle fibres. Furthermore, the expression of MDM4 was positively correlated with the percentage of fast‐twitch muscle fibres and the relative area occupied by fast‐twitch muscle fibres. [ABSTRACT FROM AUTHOR]

Background: Emerging evidence suggests that alterations in BCAA metabolism may contribute to the pathogenesis of sarcopenia. However, the relationship between branched-chain amino acids (BCAAs) and sarcopenia is incompletely understood, and existing literature presents conflicting results. In this study, we conducted a community-based study involving > 100,000 United Kingdom adults to comprehensively explore the association between BCAAs and sarcopenia, and assess the potential role of muscle mass in mediating the relationship between BCAAs and muscle strength. Methods: Multivariable linear regression analysis examined the relationship between circulating BCAAs and muscle mass/strength. Logistic regression analysis assessed the impact of circulating BCAAs and quartiles of BCAAs on sarcopenia risk. Subgroup analyses explored the variations in associations across age, and gender. Mediation analysis investigated the potential mediating effect of muscle mass on the BCAA-muscle strength relationship. Results: Among 108,017 participants (mean age: 56.40 ± 8.09 years; 46.23% men), positive associations were observed between total BCAA, isoleucine, leucine, valine, and muscle mass (beta, 0.56–2.53; p < 0.05) and between total BCAA, leucine, valine, and muscle strength (beta, 0.91–3.44; p < 0.05). Logistic regression analysis revealed that increased circulating valine was associated with a 47% reduced sarcopenia risk (odds ratio = 0.53; 95% confidence interval = 0.3–0.94; p = 0.029). Subgroup analyses demonstrated strong associations between circulating BCAAs and muscle mass/strength in men and individuals aged ≥ 60 years. Mediation analysis suggested that muscle mass completely mediated the relationship between total BCAA, and valine levels and muscle strength, partially mediated the relationship between leucine levels and muscle strength, obscuring the true effect of isoleucine on muscle strength. Conclusion: This study suggested the potential benefits of BCAAs in preserving muscle mass/strength and highlighted muscle mass might be mediator of BCAA-muscle strength association. Our findings contribute new evidence for the clinical prevention and treatment of sarcopenia and related conditions involving muscle mass/strength loss. [ABSTRACT FROM AUTHOR]

Background: People with Parkinson's (PwP) want access to timely, relevant, and specific exercise and physical activity (PA) information to enable them to manage their symptoms and maintain wellbeing and quality of life. Research that promotes exercise in this population group is limited. Little is also known about the clinical practice around PA promotion in this population, especially around the time of diagnosis. Objective: To explore the experiences, preferences, and priorities of PwP around exercise and PA promotion and assess their knowledge on these topics. Methods: A cross-sectional online survey for PwP in the United Kingdom was conducted from July to December 2021. Results: 430 participants started the survey and 405 completed it. Participants had a mean age of 65.1 (±9.2) and had been living with Parkinson's for a varying time (up to 2 years = 38%, up to 6 years = 39% and for 7 or more years = 23%). Most participants reported they had not received an education (68%; n = 276) or exercise intervention (54%; n = 217) as part of their routine management by the National Health Service (NHS) since diagnosis and had sought services privately. Knowledge of the overall benefits of exercise was good, however participants lacked specific knowledge on the impact of Parkinson's Disease (PD) on posture, falls and muscle strength. 90% of participants reported they would participate in an exercise and PA education interventions. Conclusions: PwP want exercise and PA education interventions that provide knowledge, skills and access to opportunities that enable participation. For the majority, these interventions have not been provided as part of their routine care pathway. To align with the priorities and preferences of PwP, interventions should be offered around the time of diagnosis, include content that is relevant and specific to how exercise and PA can mitigate symptoms of PD and should be delivered in person or online in a group setting. [ABSTRACT FROM AUTHOR]

Sarcopenia may increase non-alcoholic fatty liver disease (NAFLD) risk, but prevalence likely varies with different diagnostic criteria. This study examined the prevalence of sarcopenia and its defining components in adults with and without NAFLD and whether it varied by the method of muscle mass assessment [bioelectrical impedance (BIA) versus dual-energy X-ray absorptiometry (DXA)] and adjustment (height2 versus BMI). Adults (n = 7266) in the UK Biobank study (45–79 years) with and without NAFLD diagnosed by MRI, were included. Sarcopenia was defined by the 2018 European Working Group on Sarcopenia in Older People definition, with low appendicular skeletal muscle mass (ASM) assessed by BIA and DXA and adjusted for height2 or BMI. Overall, 21% of participants had NAFLD and the sex-specific prevalence of low muscle strength (3.6–7.2%) and sarcopenia (0.1–1.4%) did not differ by NAFLD status. However, NAFLD was associated with 74% (males) and 370% (females) higher prevalence of low ASM when adjusted for BMI but an 82% (males) to 89% (females) lower prevalence when adjusted for height2 (all P < 0.05). The prevalence of impaired physical function was 40% (males, P = 0.08) to 123% (females, P < 0.001) higher in NAFLD. In middle-aged and older adults, NAFLD was not associated with a higher prevalence of low muscle strength or sarcopenia but was associated with an increased risk of impaired physical function and low muscle mass when adjusted for BMI. These findings support the use of adiposity-based adjustments when assessing low muscle mass and the assessment of physical function in NAFLD. [ABSTRACT FROM AUTHOR]

Background: Muscle weakness is a prominent feature of Parkinson's disease, but whether the occurrence of this deficit in healthy adults is associated with subsequent PD diagnosis remains unclear. Objective: This study sought to examine the relationship between muscle strength, represented by grip strength and walking pace, and the risk of incident PD. Methods: A total of 422,531 participants from the UK biobank were included in this study. Longitudinal associations of grip strength and walking pace with the risk of incident PD were investigated by Cox proportional hazard models adjusting for several well-established risk factors. Subgroup and sensitivity analyses were also conducted for further validation. Results: After a median follow-up of 9.23 years, 2,118 (0.5%) individuals developed incident PD. For per 5 kg increment of absolute grip strength, there was a significant 10.2% reduction in the risk of incident PD (HR = 0.898, 95% CI [0.872–0.924], P < 0.001). Similarly, per 0.05 kg/kg increment of relative grip strength was related to a 9.2% reduced risk of incident PD (HR = 0.908, 95% CI [0.887–0.929], P < 0.001). Notably, the associations remained consistent when grip strength was calculated as quintiles. Moreover, participants with a slower walking pace demonstrated an elevated risk of incident PD (HR = 1.231, 95%CI [1.075–1.409], P = 0.003). Subgroup and sensitivity analyses further validated the robustness of the observed associations. Conclusion: Our findings showed a negative association of grip strength and walking pace with the risk of incident PD independent of important confounding factors. These results hold potential implications for the early screening of people at high-risk of PD. [ABSTRACT FROM AUTHOR]

Age-related muscle wasting and dysfunction render the elderly population vulnerable and incapacitated, while underlying mechanisms are poorly understood. Here, we implicate the CERS1 enzyme of the de novo sphingolipid synthesis pathway in the pathogenesis of age-related skeletal muscle impairment. In humans, CERS1 abundance declines with aging in skeletal muscle cells and, correlates with biological pathways involved in muscle function and myogenesis. Furthermore, CERS1 is upregulated during myogenic differentiation. Pharmacological or genetic inhibition of CERS1 in aged mice blunts myogenesis and deteriorates aged skeletal muscle mass and function, which is associated with the occurrence of morphological features typical of inflammation and fibrosis. Ablation of the CERS1 orthologue lagr-1 in Caenorhabditis elegans similarly exacerbates the age-associated decline in muscle function and integrity. We discover genetic variants reducing CERS1 expression in human skeletal muscle and Mendelian randomization analysis in the UK biobank cohort shows that these variants reduce muscle grip strength and overall health. In summary, our findings link age-related impairments in muscle function to a reduction in CERS1, thereby underlining the importance of the sphingolipid biosynthesis pathway in age-related muscle homeostasis. [ABSTRACT FROM AUTHOR]

Background Typically, the fitness of UK firefighters is assessed via submaximal estimate methods due to the low demands on time, money, expertise and equipment. However, the firefighter-specific validity of such testing in relation to maximum aerobic capacity (⁠ V ˙ O 2 max ⁠) and particularly muscular strength is not well established. Aims To examine the validity of submaximal methods to estimate V ˙ O 2 max and maximal strength in operational firefighters. Methods Twenty-two full-time operational firefighters (3 female) completed same-day submaximal (Chester Step Test; CST) and maximal (treadmill) assessments of V ˙ O 2 max ⁠ , with a sub-sample of 10 firefighters (1 female) also completing submaximal and maximal back-squat (i.e. one repetition maximum; 1RM) assessments. All participants then completed the Firefighter Simulation Test (FFST) within 2–4 days. Results CST underestimated actual V ˙ O 2 max by 1.4 ml·kg–1·min–1 (~3%), although V ˙ O 2 max values were positively correlated (r  = 0.61, P  < 0.01) and not significantly different. Estimated V ˙ O 2 max values negatively correlated with FFST performance (r  = –0.42). Predicted 1RM underestimated actual 1RM by ~2%, although these values were significantly correlated (r  = 0.99, P  < 0.001) and did not significantly differ. The strongest predictive model of FFST performance included age, body mass index, and direct maximal measures of 1RM and V ˙ O 2 max ⁠. Conclusions Submaximal back-squat testing offers good validity in estimating maximum firefighter strength without exposure to the fatigue associated with maximal methods. The CST provides a reasonably valid and cost-effective V ˙ O 2 max estimate which translates to firefighting task performance, although the error observed means it should be used cautiously when making operational decisions related to V ˙ O 2 max benchmarks. [ABSTRACT FROM AUTHOR]

The article discusses the benefits regular physical activity during menopause. Topics include types of physical activities to maintain or improve muscle strength, bone health and balance, study finding on a dose-response relationship between increased physical activity and decreased occurrence rate of cardiovascular health (CVD), and link between being physically active and reduction in breast cancer risk.

Nevin, JP, Bowling, K, Cousens, C, Bambrough, R, and Ramsdale, M. The relationship between isometric midthigh pull force-time characteristics and 2-km load-carrying performance in trained British army soldiers. J Strength Cond Res 38(2): 360-366, 2024--Load carriage is a fundamental military occupational task. As such, the aim of this study was to assess the relationship between isometric force-time characteristics and loaded march performance. Furthermore, this study aimed to investigate the relationship between isometric force-time characteristics and standing long jump (SLJ) performance. Thirty-nine, full-trained, male British Army infantry soldiers (age 3166.1 years; height 17667.3 cm; body mass 85.8611.5 kg) performed three isometric midthigh pull trials, three SLJ trials, and a 2-km loadedmarch carrying an external load of 25 kg. Both the isometricmidthigh pull test (intraclass correlation coefficient [ICC] 0.965) and SLJ (ICC 0.916) demonstrated excellent reliability. Relationships between all variables were assessed using Pearson's correlation coefficient. Isometric peak force (r520.059), relative peak force (r520.135), and rate of force development (r520.162) displayed a small correlation with loadedmarch time to completion. However, isometric relative peak force displayed a large relationship with SLJ performance (r50.545; p5,0.01). Our data demonstrate that isometric lower-limb strength measures account for, 2% of the total variance observed in 2-km loaded march performance. As such, the use of isometric lower-limb force-time characteristics as a proxy measure of load-carrying ability should be questioned. However, relative isometric strength seems to demonstrate a significant relationship with SLJ performance. As such, isometric testing may have utility in regard to assessing explosive strength, monitoring neuromuscular fatigue, and assessing training readiness in military populations. [ABSTRACT FROM AUTHOR]

Isokinetic dynamometry is the clinical gold standard for strength assessment but testing protocols and outcome metrics can lack functional relevance. To quantify the influence of dynamometer configuration on eccentric hamstring strength metrics, 23 trained participants completed isokinetic eccentric knee flexor trials at 180°·s−1 in a seated and extended hip position. The extended position elicited a greater peak torque (P = 0.04) which was achieved at a significantly (P < 0.001) greater degree of knee flexion. Isokinetic range and functional range (defined as 85% of peak torque) were consistent at ~44° and ~21°, respectively, across trials, but were achieved with a more flexed knee in the extended hip configuration. Therefore, whilst the extended hip configuration might better reflect the biarticular nature of the hamstring musculature and the mechanism of hamstring strain injury, the sensitivity of strength metrics to configuration has implications for clinical assessment and training adaptations. [ABSTRACT FROM AUTHOR]

Background: Injuries are the leading cause of death and disability in preschool children who are subject to specific risk factors. We sought to clarify the determinants of unintentional injuries in children aged 5 years and under in high‐income countries and report on the methodological quality of the selected studies. Methods: A systematic review was conducted of observational studies investigating determinants of unintentional injury in children aged 0–5. Searches were conducted in Web of Science, Medline, Embase, PsycInfo and CINAHL. All methods of data analysis and reporting followed the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA 2021) guidelines. Determinants are reported at the child, parental, household and area level. Results: An initial search revealed 6179 records. Nineteen studies met the inclusion criteria: 17 cohort studies and 2 case control studies. While studies included longitudinal surveys and administrative healthcare data analysis, the highest quality studies examined were case–control designs. Child factors associated with unintentional injury include male gender, age of the child at the time of injury, advanced gross motor score, sleeping problems, birth order, attention deficit hyperactivity disorder (ADHD) diagnosis and below average score on the standard strengths and difficulties scale. Parental factors associated with unintentional injuries included younger parenthood, poor maternal mental health, hazardous or harmful drinking by an adult within the home, substance misuse, low maternal education, low paternal involvement in childcare and routine and manual socioeconomic classification. Household factors associated with injury were social rented accommodation, single‐parent household, White ethnicity in the United Kingdom, number of children in the home and parental perception of a disorganised home environment. Area‐level factors associated with injury were area‐level deprivation and geographic remoteness. Conclusion: Child factors were the strongest risk factors for injury, whereas parental factors were the most consistent. Further research is needed to examine the role of supervision in the relationships between these risk factors and injury. Injury intent should be considered in studies using administrative healthcare data. Prospective research may consider utilising linked survey and administrative data to counter the inherent weaknesses of these research approaches. [ABSTRACT FROM AUTHOR]

Aims: To explore the associations between handgrip strength (HGS) and skeletal muscle mass (SMM) with all‐cause and cardiovascular disease (CVD) mortality risk in type 2 diabetes (T2DM) patients. Materials and Methods: Data were obtained from the UK Biobank. Baseline survey was conducted between 2006 and 2010, and followed up for a median of 12.52 years. HGS was measured using dynamometer, and SMM was measured using bioelectrical impedance method. Mortality was available via links to the National Health Service Information Centre. Sex‐specific analyses were conducted. Results: A total of 13 392 T2DM participants were included, with a mean age of 60.39 years and 52.35% men. During the follow‐up, there were 3006 (22.45%) deaths, including 746 (5.57%) CVD deaths. The risk for all‐cause mortality and CVD mortality among both men and women increased progressively with decreasing HGS quartiles (p trend <.05). A 1 SD decrease in HGS was found to both increase the all‐cause risk (HR: 1.31 [95% CI: 1.24–1.38]) and CVD mortality risk (HR: 1.35 [95% CI: 1.22–1.50]) for men, and all‐cause risk (HR: 1.26 [95% CI: 1.11–1.42]) and CVD mortality risk (HR: 1.43 [95% CI: 1.09–1.89]) for women. There was no statistically significant trend association between SMM/height2 and mortality risk, and the restricted cubic regression splines indicated that SMM/height2 showed a U‐shaped nonlinear relationship (pnonlinear <.05). Conclusions: Grip strength displayed a linear downward trend with mortality risk among T2DM patients, whereas muscle mass showed a U‐shaped relationship. Low grip strength seemed to be a better predictor for mortality compared to low muscle mass. [ABSTRACT FROM AUTHOR]

Frailty is associated with negative health outcomes, disability, and mortality. Physical activity is an effective intervention to improve functional health status. However, the effect of resistance training on multidimensional health in frail older adults remains unclear. This randomized controlled trial was conducted in a U.K. residential care home to assess feasibility with limited efficacy testing on health and functional outcomes and to inform a future definitive randomized controlled trial. Eleven frail older adults (>65 years) completed a 6-week machine-based resistance training protocol three times a week. Uptake and retention were greater than 80%. The measures and intervention were found to be acceptable and practicable. The analyses indicated large improvements in functional capacity, frailty, and strength in the intervention group compared with the controls. These findings support the feasibility of a definitive randomized controlled trial and reinforce the value of resistance training in this population. This trial was registered with ClinicalTrials.gov: NCT03141879. [ABSTRACT FROM AUTHOR]

Strength training recommendations have been embedded within the UK's Chief Medical Officers' physical activity guidelines since 2011. There is limited evidence that these recommendations are used by exercise instructors in the community to underpin strength training prescription in the older adult population. This study aimed to explore exercise instructors' awareness and utilisation of the guidelines when prescribing strength training to older adults. Fifteen exercise instructors working with older adults in the UK participated in one online interview. A general inductive approach was conducted and thematic analysis allowed for major themes to be identified from the raw data. We found that most exercise instructors (n = 9), but not all (n = 6), were aware of the guidelines. Only one instructor (n = 1) had reportedly implemented the guidelines into their practice; other instructors reported that the guidelines were irrelevant. Instead, each of the instructors had their preferred sources of information that they relied on to underpin their exercise prescription, and each had their own interpretation of 'evidence-based strength training.' This individualised interpretation resulted in exceptionally varied prescription in the community and does not necessarily align with the progressive, evidence-based prescription known to build muscular strength. We suggest that (i) more detail on how to build muscular strength be embedded within the guidelines, (ii) a handbook on how to implement the guidelines be made available, (iii) theoretical and practical teaching materials and courses be updated, and/or (iv) a re-(education) of exercise instructors already in the field may be necessary to bring about a consistent, evidence-based strength prescription necessary for the best possible health and longevity outcomes for our ageing population. [ABSTRACT FROM AUTHOR]

Background: Muscle weakness is associated with adverse clinical outcomes including disability and mortality. We report demographic, anthropometric and lifestyle correlates of grip strength in UK and Japanese population-based cohorts. Aim: To report prevalence of low grip strength according to 2019 European Working Group on Sarcopenia in Older People (EWGSOP2) and 2019 Asian Working Group for Sarcopenia (AWGS 2019) thresholds and to consider correlates of grip strength in Eastern and Western populations. Methods: UK (1572 men; 1415 women) and Japanese (519 men; 1027 women) participants were recruited from two cohorts harmonised by consensus. Muscle strength was measured by grip strength dynamometry. Potential correlates of grip strength were examined using sex-stratified linear regression; univariate correlates (p < 0.05) were included in mutually adjusted models. Results: Mean (SD) age was 66.2 (2.8) and 65.8 (12.3) in UK and Japanese cohorts, respectively. Prevalence of low grip strength was higher in Japanese participants (EWGSOP2 5.4% versus 2.4%, AWGS 2019 9.0% versus 3.7%). In both cohorts and sexes, univariate correlates of lower grip strength were older age, shorter height, not consuming alcohol, leaving education earlier and greater comorbidity. Apart from older age and shorter height, the only factors related to lower grip strength in mutually adjusted analyses were greater comorbidity among UK participants (kg difference in grip strength (95%CI) per additional comorbidity − 0.60(− 0.98, − 0.21) among men and − 0.50(− 0.86, − 0.13) among women) and not consuming alcohol among Japanese men (− 1.33(− 2.51, − 0.15)). Discussion: Correlates of muscle strength were similar in both cohorts. Conclusions: A global approach to age-related muscle weakness prevention may be appropriate. [ABSTRACT FROM AUTHOR]

Differences in preferences for body size between cultures are well documented. A well known explanation is that differences are a result of psychological adaptation to local environments. Since the optimal body size (often measured as Body Mass Index/BMI, weight divided by squared height kg/m2) for health differs between areas, the attractiveness and health judgements should also be different. Until now, no study has directly tested whether the difference in attractiveness perception is accompanied by a difference in health perception. In the current study, we compared the attractiveness and health judgements of male and female bodies varying in BMI and muscularity between British and Chinese participants. Since the health risks are greater for Chinese than British individuals with increasing BMI, one may expect Chinese participants to perceive a lower BMI as more attractive and healthier than British participants. Analyses showed that, although the Chinese participants preferred thinner partners compared to their British counterparts, there was no difference in the health judgements made by Chinese and British participants. Moreover, the male and female bodies that were seen as most attractive were thinner than those perceived as most healthy by Chinese participants. These findings challenge the adaptation account that people adjust their mate preferences to match what is most healthy in local environments. [ABSTRACT FROM AUTHOR]

Background: Cervical traumatic spinal cord injury is a devastating condition. Current management (bony decompression) may be inadequate as after acute severe TSCI, the swollen spinal cord may become compressed against the surrounding tough membrane, the dura. DISCUS will test the hypothesis that, after acute, severe traumatic cervical spinal cord injury, the addition of dural decompression to bony decompression improves muscle strength in the limbs at 6 months, compared with bony decompression alone. Methods: This is a prospective, phase III, multicenter, randomized controlled superiority trial. We aim to recruit 222 adults with acute, severe, traumatic cervical spinal cord injury with an American Spinal Injury Association Impairment Scale grade A, B, or C who will be randomized 1:1 to undergo bony decompression alone or bony decompression with duroplasty. Patients and outcome assessors are blinded to study arm. The primary outcome is change in the motor score at 6 months vs. admission; secondary outcomes assess function (grasp, walking, urinary + anal sphincters), quality of life, complications, need for further surgery, and mortality, at 6 months and 12 months from randomization. A subgroup of at least 50 patients (25/arm) also has observational monitoring from the injury site using a pressure probe (intraspinal pressure, spinal cord perfusion pressure) and/or microdialysis catheter (cord metabolism: tissue glucose, lactate, pyruvate, lactate to pyruvate ratio, glutamate, glycerol; cord inflammation: tissue chemokines/cytokines). Patients are recruited from the UK and internationally, with UK recruitment supported by an integrated QuinteT recruitment intervention to optimize recruitment and informed consent processes. Estimated study duration is 72 months (6 months set-up, 48 months recruitment, 12 months to complete follow-up, 6 months data analysis and reporting results). Discussion: We anticipate that the addition of duroplasty to standard of care will improve muscle strength; this has benefits for patients and carers, as well as substantial gains for health services and society including economic implications. If the addition of duroplasty to standard treatment is beneficial, it is anticipated that duroplasty will become standard of care. Trial registration: IRAS: 292031 (England, Wales, Northern Ireland) - Registration date: 24 May 2021, 296518 (Scotland), ISRCTN: 25573423 (Registration date: 2 June 2021); ClinicalTrials.gov number : NCT04936620 (Registration date: 21 June 2021); NIHR CRN 48627 (Registration date: 24 May 2021). [ABSTRACT FROM AUTHOR]

Background Low vitamin D status is a widespread phenomenon. Similarly, muscle weakness, often indicated by low grip strength, is another public health concern; however, the vitamin D–grip strength relationship is equivocal. It is important to understand whether variation in vitamin D status causally influences muscle strength to elucidate whether supplementation may help prevent/treat muscle weakness. Methods UK Biobank participants, aged 37–73 years, with valid data on Vitamin D status (circulating 25-hydroxyvitamin D [25(OH)D] concentration) and maximum grip strength were included (N = 368,890). We examined sex-specific cross-sectional associations between 25(OH)D and grip strength. Using Mendelian randomization (MR), we estimated the strength of the 25(OH)D–grip strength associations using genetic instruments for 25(OH)D as our exposure. Crucially, because potential effects of vitamin D supplementation on strength could vary by underlying 25(OH)D status, we allowed for nonlinear relationships between 25(OH)D and strength in all analyses. Results Mean (SD) of 25(OH)D was 50 (21) nmol/L in males and females. In cross-sectional analyses, there was evidence of nonlinear associations between 25(OH)D and strength, for example, compared to males with 50 nmol/L circulating 25(OH)D, males with 75 nmol/L had 0.36 kg (0.31,0.40) stronger grip; males with 25 nmol/L had 1.01 kg (95% confidence interval [CI]: 0.93, 1.08) weaker grip. In MR analyses, linear and nonlinear models fitted the data similarly well, for example, 25 nmol/L higher circulating 25(OH)D in males was associated with 0.25 kg (−0.05, 0.55) greater grip (regardless of initial 25(OH)D status). Results were similar, albeit weaker, for females. Conclusions Using two different methods to triangulate evidence, our findings suggest moderate to small causal links between circulating 25(OH)D and grip strength. [ABSTRACT FROM AUTHOR]

Malnutrition in adults can often go undetected and untreated. [ABSTRACT FROM AUTHOR]

Introduction: Current evidence suggests the emergence of a novel syndrome (long COVID syndrome) due to sequels and persistent COVID-19 symptoms. Respiratory muscle training improves respiratory muscle strength, exercise capacity, diaphragm thickness, and dyspnea, especially in patients with decreased respiratory muscle strength. This study aims to evaluate the effectiveness of a protocol for home-based inspiratory muscle training to improve respiratory muscle strength, dyspnea, and quality of life of patients post-COVID-19. Methods and analyses: This randomized, controlled, double-blind clinical trial will be conducted at the Instituto de Medicina Tropical of Universidade Federal do Rio Grande do Norte (Brazil). Sample size will be determined using maximal inspiratory pressure after a pilot study with five patients per group (total of 10 patients). Patients included in the study will be evaluated in three moments: pre-training (initial), post-training (three weeks), and retention (24 weeks). The sample will be randomized in two groups: active (IMT using 30% of IMT and load increase of 10% of initial IMT every week. Patients will perform 30 repetitions, twice a day (morning and afternoon), for seven consecutive days, and six weeks) and SHAM (IMT without load). The following measurements will be assessed: anthropometry, respiratory muscle strength, pulmonary volume and capacity, dyspnea, perception of effort and lower limb fatigue, handgrip strength, functional capacity, anxiety, depression, and functional status. After initial evaluation, all patients will receive a POWERbreathe® (POWERbreathe®, HaB Ltd, Southam, UK) device to perform the training. Normality will be verified using Shapiro-Wilk or Kolmogorov-Smirnov, according to the number of patients included. Variables presenting nonparametric distribution will be compared using Wilcoxon (intragroup analysis) and Mann-Whitney test (intergroup analysis), whereas repeated measures two-way ANOVA will be performed in case of parametric distribution. Dunn's post hoc test will be used to identify significant differences in the two-way ANOVA test. Primary outcomes: Respiratory muscle strength, dyspnea, and quality of life of post-COVID-19 patients. Second outcomes: Pulmonary function, dyspnea, exercise tolerance, handgrip strength, anxiety, depression, and functional status. Trial registration: Trial register number NCT05077241. [ABSTRACT FROM AUTHOR]

Increased levels of vitamin D in the summer months from natural seasonal variations in sun exposure have been linked to improvements in musculoskeletal health and function in UK populations; however, studies have shown that differences in lifestyles because of disability can inhibit the natural vitamin D increase in these populations. We hypothesized that men with cerebral palsy (CP) will experience smaller increases in 25-hydroxyvitamin D (25(OH)D) from winter to summer and men with CP will not experience any improvements in musculoskeletal health and function during the summer. A longitudinal observational study in 16 ambulant men with CP aged 21.0 ± 1.3 years and 16 healthy, physical activity matched, typically developed controls aged 25.4 ± 2.6 years, completed assessments of serum 25(OH)D and parathyroid hormone during winter and summer. Neuromuscular outcomes included vastus lateralis size, knee extensor strength, 10-m sprint, vertical jumps, and grip strength. Bone ultrasounds were performed to obtain radius and tibia T and Z scores. Men with CP and typically developed controls showed a 70.5% and 85.7% increase in serum 25(OH)D from winter to summer months, respectively. Neither group showed seasonal effect on neuromuscular outcomes muscle strength, size, vertical jump, or tibia and radius T and Z scores. A seasonal interaction effect was seen in the tibia T and Z scores (P <.05). In conclusion, there were similar seasonal increases in 25(OH)D observed in men with CP and typically developed controls, but serum 25(OH)D levels were still considered insufficient to improve bone or neuromuscular outcomes. [Display omitted] Cerebral palsy (CP) is a brain injury in utero that commonly leads to muscle spasticity that reduces range of motion (RoM) and alters gait, resulting in poor musculoskeletal (MSK) health. Vitamin D may improve MSK health but seasonal changes in the United Kingdom cause these to fluctuate. Sixteen men with CP were measured for vitamin D and MSK outcomes during winter and summer. There was a 70.5% increase in vitamin D from winter to summer but showed no seasonal changes on MSK outcomes. [ABSTRACT FROM AUTHOR]

Background Genetic factors and muscle strength both contribute to the risk of major depressive disorder (MDD), but whether high muscle strength can offset the risk of MDD with different genetic risk is unknown. This study aims to examine whether a higher muscle strength is associated with lower risk of MDD regardless of genetic risk among middle-aged and older adults. Methods This cohort study obtained data from the UK Biobank, which includes 345,621 individuals aged 40–69 years (mean (standard deviation): 56.7 (7.99) years) without baseline MDD. Polygenic risk score for MDD was categorised as low, intermediate or high. The mean of the right- and left-hand grip strength values was used in the analysis and was divided into three categories. Results 9,753 individuals developed MDD within 2,752,461 person-years of follow-up. The multivariable adjusted hazard ratios (HRs) (95% confidence intervals (CIs)) of MDD across increased grip strength categories were 1.00, 0.72 (0.68–0.75) and 0.56 (0.53–0.59) (P for trend <0.0001). The HRs (95% CIs) of incident MDD across the genetic risk categories were 1.00, 1.11 (1.05–1.17) and 1.20 (1.13–1.28) (P for trend <0.0001); 4.07% of individuals with a high genetic risk and low grip strength developed MDD, and 1.72% of individuals with a low genetic risk and high grip strength developed MDD, with an HR (95% CI) of 0.44 (0.39–0.50). Conclusions Both muscle strength and genetic risk were significantly associated with incident MDD. A higher muscle strength was associated with a lower MDD risk among individuals with a high genetic risk. Improving muscle strength should be encouraged for all individuals, including individuals with high genetic risk for MDD. [ABSTRACT FROM AUTHOR]

Interpreting the physical qualities of youth athletes is complex due to the effects of growth, maturation and development. This study aimed to evaluate the effect of position, chronological age, relative age and maturation on the physical qualities of elite male academy rugby union players. 1,424 participants (n = 2,381 observations) from nine Rugby Football Union regional academies prospectively completed a physical testing battery at three time points, across three playing seasons. Anthropometrics, body composition, muscular power, muscular strength, speed, aerobic capacity and running momentum were assessed. Positional differences were identified for all physical qualities. The largest effect sizes were observed for the associations between chronological age (d = 0.65–0.73) and maturation (d = −0.77 to −0.69) and body mass related variables (i.e. body mass and running momentum). Relative strength, maximum velocity and aerobic capacity were the only models to include two fixed effects with all other models including at least three fixed effects (i.e. position and a combination of chronological age, relative age and maturation). These findings suggest a multidimensional approach considering position, chronological age, relative age and maturation is required to effectively assess the physical qualities of male age grade rugby union players. Therefore practitioners should use regression equations rather than traditional descriptive statistic tables to provide individualised normative comparisons thus enhancing the application of testing results for talent identification and player development. Highlights Practitioners should record and incorporate position, chronological age, relative age and maturation into the physical evaluation of elite academy rugby union players. The regression equations provided within this study offer highly generalisable comparative values that are specific to a players chronological and biological development. Through the use of enhanced player evaluation practitioners will be able to make more informed decisions surrounding talent identification and athlete development. [ABSTRACT FROM AUTHOR]

Background Sarcopenia, characterised by an accelerated loss of skeletal muscle mass and function, is associated with negative outcomes. This study aimed to evaluate factors associated with skeletal muscle strength, mass and sarcopenia, particularly protein intake, and to assess whether shared twin characteristics are important. Methods This study utilised cross-sectional data from a study of community-dwelling twins aged ≥60 years. Multivariable logistic regression and between- and within-twin pair regression modelling were used. Results Participants (n  = 3,302) were 89% female (n  = 2,923), aged a mean of 72.1 (±7.3) years and composed of 858 (55%) monozygotic, 709 (45%) dizygotic twin pairs and 168 individual lone twins. Using optimal protein intake as the reference group (1.0–1.3 g/kg/day), there was no significant association between protein intake (neither high nor low) and low muscle strength, or between low protein intake and sarcopenia (odds ratio (OR) 0.7; 95% confidence interval (CI) 0.39–1.25; P  = 0.229) in unadjusted models. High protein intake (>1.3 g/kg/day) was associated with low muscle mass (OR 1.76; 95% CI 1.39–2.24; P  < 0.0001), while low protein intake was protective (OR 0.52; 95% CI 0.40–0.67; P  < 0.0001). High protein intake was associated with sarcopenia (OR 2.04; 95% CI 1.21–3.44; P  = 0.008), and this was robust to adjustment for demographic, anthropometric and dietary factors. The association between muscle strength and weight, body mass index, healthy eating index, protein intake and alpha diversity was not significantly influenced by shared twin factors, indicating greater amenability to interventions. Conclusions High protein intake is associated with sarcopenia in a cohort of healthy older twins. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to determine the independent effects of obesity and dynapenia on falls risk, areal bone mineral density, and fracture risk (lower extremity or all other fractures). Methods: A total of 16,147 women (aged 60‐82 years) from the UK Biobank were categorized by handgrip strength (HGS; dynapenia status: HGS ≤ 21 kg) and body weight (BMI: normal weight, overweight, or obesity). Multiple logistic regression models examined the association among dynapenia and obesity and self‐reported falls (previous 12 months), lower extremity fractures, and all other fractures (previous 5 years). Results: A total of 3793/16,147 women fell, and 1413/15,570 (9.1%) eligible women experienced fall‐related fractures. Obesity (odds ratio [OR] 1.25; 95% CI: 1.12‐1.38) and dynapenia (OR 0.87; 95% CI: 0.77‐0.98) were both independently associated with greater lower extremity fracture risk, independently of areal bone mineral density. However, considering all other fracture sites, obesity conferred protection (OR 0.77; 95% CI: 0.61‐0.96), except in those with low HGS, who had an equivalent fracture risk to those with normal weight (OR 1.06; 95% CI: 0.82‐1.38). Conclusions: Dynapenia further increases the increased risk of leg and ankle fractures in obesity and counteracts the protective effects of obesity on fracture risk at all other sites (wrist, arm, hip, spine, other bones). [ABSTRACT FROM AUTHOR]

We examined the joint associations of BMI category and grip strength tertile with risk of severe COVID-19 (inpatient COVID-19 or COVID-19 mortality) in 327 500 UK Biobank participants. Compared to normal-weight males with high grip strength, the odds ratio (95 % confidence interval) for males with obesity with low grip strength was 2.39 (1.59–3.60), but 1.52 (0.98–2.35) for males with obesity with a high grip strength. A higher grip strength did not appear to be associated with lower risk of severe COVID-19 in females. Muscle mass and strength development should be considered as a means to reduce risk of severe COVID-19 for males with obesity. [ABSTRACT FROM AUTHOR]

Background: Limb strength is a central component of neurological assessment and monitoring in nursing practice, yet there is a lack of research examining the tools used by nurses or challenges nurses encounter when using these tools. The evidence base is lacking to inform effective practice and the underpinning educational approaches. Aim: To determine which tools are used by UK and Irish neuroscience nurses in the assessment of limb strength and the associated challenges and variations in practice. Methods: This study used an online self-reported survey design to ascertain which tools neuroscience nurses used and their experience of using these (n=160). Findings: Practices varied, with a dominance of two tools being used in practice: the Medical Research Council scale and the 'normal power' to 'no movement' scale found on the neurological observation chart. Most respondents used the same tool across all conditions. Conclusion: This study highlights variations in assessment practice and the absence of a sound evidence base behind choice of motor limb strength assessment tools used. [ABSTRACT FROM AUTHOR]

Background sarcopenia is a disease that involves the degeneration of muscle strength, muscle mass and physical performance. It remains unknown whether air pollution exposure increases the risk of sarcopenia. Methods the baseline survey of the UK Biobank was used in this study. Sarcopenia was identified according to European Working Group on Sarcopenia in Older People 2 (EWGSOP2) and classified into non-sarcopenia and probable sarcopenia. Land use regressions were used to estimate concentrations of particulate matter (PM2.5), coarse particles (PMcoarse), PM10, PM2.5 absorbance, nitrogen dioxide (NO2) and nitrogen oxides (NO x). Logistic regression models were applied to estimate the associations between air pollution and sarcopenia and its components. Results out of 352,265 participants, 28,710 (8.2%) were identified with probable sarcopenia. In adjusted models, there were increased odds of probable sarcopenia for each interquartile range increase in PM2.5 (OR: 1.06; 95% CI: 1.04, 1.07), PM10 (OR: 1.15; 95% CI: 1.13, 1.17), PMcoarse (OR: 1.02; 95% CI:1.01, 1.03), PM2.5 absorbance (OR: 1.08; 95% CI: 1.07, 1.10), NO2 (OR: 1.12; 95% CI:1.10, 1.14) and NO x (OR: 1.06; 95% CI: 1.05, 1.08). Conclusions this study suggests that exposure to ambient air pollution might be one risk factor of sarcopenia. Prospective studies are needed to further confirm our findings. [ABSTRACT FROM AUTHOR]

Sarcopenia is a skeletal muscle disorder that commonly occurs with advancing age as well as with a number of long-term conditions. Recognition in clinical practice is relatively recent but important because of the association between sarcopenia and a range of adverse effects on health including impaired mobility, increased morbidity and mortality. Originally characterised as loss of muscle mass, the definition has evolved to focus on loss of skeletal muscle function, particularly strength, through a number of international definitions such as that of the European Working Group on Sarcopenia in Older People most recently revised in 2019. Progress in the decades ahead is likely to be seen with regard to use of routine health data, prescription of resistance exercise, translation of biology and epidemiology into first in man studies for new treatments, and focus on sarcopenia in low and middle-income countries. Immediate next steps include the newly formed Global Leadership Initiative on Sarcopenia to develop international consensus on definition and diagnosis. [ABSTRACT FROM AUTHOR]

Although athletes from sports such as rugby have greater lean mass and strength during their playing careers, little is known about these characteristics post-retirement. Therefore, this study investigated lean mass, strength, and muscle quality in retired elite and amateur rugby players and non-contact athletes. Retired elite male rugby players (n=42, 43.9±10.3 y; 101.1±13.4 kg; 1.82±0.09 m), amateur rugby players (n=46, 48.0±10.5 y; 98.9±16.6 kg; 1.79±0.07 m) and non-contact athletes (n=30, 51.3±12.5 y; 91.3±13.4 kg; 1.79±0.07 m) received one total body dual-energy X-ray absorptiometry assessment of appendicular lean mass (ALM) and ALM index (ALMI). Grip strength was measured, and muscle quality (grip strength/unit of arm lean mass) was calculated. Sarcopenia was identified as ALMI<7.23 kg/m2 and handgrip strength<37.2 kg. Total lean mass, ALM and grip strength were greater in the elite rugby compared to amateur rugby and non-contact groups (p<0.01). There were no significant differences in muscle quality or sarcopenia prevalence. Retired elite rugby players had greater lean mass and grip strength than amateur rugby and non-contact athletes, although muscle quality was similar. The greater lean mass and strength might reflect genetic influences or previous participation in a highly physical sport. [ABSTRACT FROM AUTHOR]

Aging triggers intricate physiological changes, particularly in whole-body fat-free mass (FFM) and handgrip strength, affecting overall health and independence. Despite existing research, the broader significance of how muscle health is affected by the intricate interplay of lifestyle factors simultaneously during aging needs more exploration. This study aims to examine how nutrition, physical activity, and sleep impact on FFM and handgrip strength in middle-aged men and women, facilitating future personalized recommendations for preserving muscle health. The cross-sectional analysis of the UK Biobank involved 45,984 individuals (54 % women) aged 40–70 years with a complete dataset. Multiple linear regression explored determinants of FFM and handgrip strength, considering traditional, socio-demographics, medication use and smoking as covariates, with sex and age (younger and older than 55 years) stratifications. In older men and women, higher physical activity beneficially affect both FFM (respectively Β = 3.36 × 10−3, p -value = 1.66 × 10−3; Β = 2.52 × 10−3, p -value = 3.57 × 10−4) and handgrip strength (Β = 6.05 × 10−3, p-value = 7.99 × 10−5, Β = 8.98 × 10−3, p -value = 2.95 × 10−15). Similar results were found in fiber intake for FFM in older men and women (respectively B = 3.00 × 10−2, p -value = 2.76 × 10−5; B = 2.68 × 10−2, p-value = 1.78 × 10−9) and handgrip strength (Β = 3.27 × 10−2, p-value = 1.40 × 10−3; Β = 3.12 × 10−2, p-value = 1.34 × 10−5). Other lifestyle factors influence FFM and handgrip strength differently. Key determinants influencing handgrip strength included higher protein intake, lower water intake, higher alcohol intake, and extended sleep duration whereas mainly higher water intake is associated with higher FFM. In both men and women, the main factors associated with FFM and handgrip strength are physical activity and fiber intake, which may underlie a connection between gut and muscle health. Given the observed complexity of muscle health in the age and sex strata, further longitudinal research is needed to provide personalized lifestyle recommendations. • Lifestyle factors are associated differently in middle-aged men and women. • Physical activity and fiber intake associated with higher handgrip strength and FFM • Protein intake reveals only associated with handgrip strength in men. • Low-to-moderate alcohol intake associated with higher handgrip strength [ABSTRACT FROM AUTHOR]

Cross-sectional studies have reported that lower muscle mass and strength are risk factors for non-alcoholic fatty liver disease (NAFLD). However, the evidence from prospective studies is limited. This study examined both the strength and pattern of the associations between these 2 physical capability markers and severe NAFLD using data from the UK Biobank study. A total of 333,295 participants were included in this prospective study. Grip strength was measured using a Jamar J00105 hydraulic hand dynamometer, and the Janssen equation was used to estimate skeletal muscle mass by bioelectrical impedance. Muscle mass was adjusted for body weight and all exposures were sex-standardised. Associations of muscle mass and strength with severe NAFLD (defined as hospital admission or death) were first investigated by tertile of each exposure using Cox proportional hazard models. Non-linear associations were investigated using penalised cubic splines fitted in the Cox proportional hazard models. After a median follow-up of 10 years (IQR 9.3 to 10.7 years), 3,311 individuals had severe NAFLD (3,277 hospitalisations and 34 deaths). Compared with the lowest tertile of muscle mass, the risk of severe NAFLD was lower in the middle (hazard ratio 0.76; 95% CI 0.70–0.83) and the highest tertile (hazard ratio 0.46; 95% CI 0.40–0.52). Tertiles of grip strength showed a similar pattern. Non-linearity was only identified for muscle mass (p <0.001). Being on the lower tertile of grip strength and muscle mass accounted for 17.7% and 33.1% of severe NAFLD cases, respectively. Lower muscle mass and grip strength were associated with higher risk of developing severe NAFLD. Interventions to improve physical capability may be protective, but this needs to be investigated in appropriately designed trials. Lower muscle mass – both quantity and quality – were associated with a higher risk of severe non-alcoholic fatty liver disease. Therefore, improving muscle mass might be a protective factor against this increasing public health problem. [Display omitted] • This is the first European cohort study exploring both grip strength and muscle mass associations with NAFLD. • Lower muscle mass and grip strength were associated with a higher risk of incident NAFLD. • One lower tertile of grip strength and muscle mass accounted for 17.7% and 33.1% of diagnosed incident cases, respectively. [ABSTRACT FROM AUTHOR]

Purpose: To examine the effects of 24-h travel west across 11 time zones on subjective jet-lag and wellness responses together with self-reported sleep and upper respiratory symptoms in 18 professional rugby league players. Methods: Measures were obtained 1 or 2 d before (pretravel) and 2, 6, and 8 d after travel (post-2, post-6, and post-8) from Australia to the United Kingdom (UK) for the 2015 World Club Series. Results: Compared with pretravel, subjective jet-lag remained significantly elevated on post-8 (3.1 ± 2.3, P < .05, d > 0.90), although it was greatest on post-2 (4.1 ± 1.4). Self-reported sleep-onset limes were significantly earlier on post-2 than at all other time points (P < .05, d > 0.90), and large effect sizes suggested that wake times were earlier on post-2 than on post-6 and post-8 (d > 0.90). Although significantly more upper respiratory symptoms were reported on post-6 than at pretravel (P < .05, d ☒ K 0.90), no incidence of injury and negligible changes in wellness and muscle strength and range of motion (P > .05, d < 0.90) were evident after travel. Conclusions: Results suggest that westward long-haul travel between Australia and the UK exacerbates subjective jet-lag and sleep responses, along with upper respiratory symptoms, in professional rugby league players. Of note, the increase in self-reported upper respiratory symptoms is a reminder that the demands of long-haul travel may be an additional concern in jet-lag for traveling athletes. However, due to the lack of sport-specific performance measures, it is still unclear whether international travel interferes with training to the extent that subsequent competition performance is impaired. [ABSTRACT FROM AUTHOR]

Pelvic floor dysfunction (PFD) is a multifactorial condition that clinically manifests as the pelvic prolapse, urinary and/or rectal incontinence, and sexual dysfunction. We aimed to evaluate the efficacy of two pelvic floor trainers for the prevention of PFD in women during the postpartum period. This was a prospective, randomized, open-label study in 70 women in the postpartum period. Participants were randomized to complete a daily, 20-min set of pelvic floor muscle exercises using the EmbaGYN (UK; Group 1, n = 40) or the Magic Kegel Master device (China; Group 2, n = 40) for 4 weeks. All participants anonymously completed the PFDI-20 questionnaire and FSFI form at baseline and last visit. Pelvic floor muscle strength was measured using the XFT-0010 device. After the completion of the 4-week pelvic floor muscle exercise program, there was a significant decrease in the rates of all PFD symptoms including pelvic organ prolapse and urinary and/or fecal incontinence in both groups. The rates of sexual dysfunction after the exercise program decreased significantly only in Group II (69.4 versus 25.0%; р =.001). After the program, Group I showed a significant reduction in the number of women with symptoms of urgent urinary incontinence versus baseline (35.3 versus 8.8% p =.009). Similarly, the rates of urine loss associated with coughing, sneezing or laughing in Group I decreased from 41.2% at baseline to 11.8% after the program (р =.006) and the rates of urine leakage independent of physical activity from 23.5 to 5.9% (p =.040), respectively. The 4-week postpartum pelvic floor muscle exercise program utilizing the EmbaGYN or Magic Kegel Master device has significantly increased the pelvic floor muscle strength and decreased the symptoms of pelvic organ prolapse, urinary and fecal incontinence. The use of the Magic Kegel Master device significantly reduced the symptoms of sexual dysfunction. The use of the EmbaGYN device was effective in addressing the individual symptoms of urinary incontinence. [ABSTRACT FROM AUTHOR]

Introduction: Grip strength is the most commonly used muscle strength proxy in clinical research. However, evidence regarding the associations of grip strength with cancer has been mainly restricted to overall cancer risk. Therefore, this study aims to evaluate the associations between grip strength relative to BMI and 15 cancer sites as well as with all-cause cancer mortality.Methods: A total of 445,555 participants (53.8% women, mean age=56.3 years) were recruited across the United Kingdom. The association of grip strength relative to BMI (expressed as 1 SD) with incidence and mortality from 15 cancer sites was investigated using Cox proportional hazard models. All analyses were conducted in April 2021.Results: Over an 8.8-year follow-up period, 37,291 patients were diagnosed with cancer, and 11,363 died of it. After covariate adjustment, higher relative grip strength per 1 SD was associated with a lower risk of incident endometrial (hazard ratio=0.76, 95% CI=0.71, 0.81), liver (hazard ratio=0.81, 95% CI=0.74, 0.88), gallbladder (hazard ratio=0.83, 95% CI=0.73, 0.94), kidney (hazard ratio=0.89, 95% CI=0.84, 0.95), and colorectal (hazard ratio=0.94, 95% CI=0.91, 0.98) cancer as well as with lower risk of gallbladder, colorectal, endometrial, liver, and all-cause cancer mortality.Conclusions: Grip strength relative to BMI was associated with incidence and mortality from endometrial, gallbladder, colorectal, liver, all-cause cancer, and breast and kidney cancer incidence, independent of major confounding factors, including comorbidity, diet, and physical activity. [ABSTRACT FROM AUTHOR]

Background Weak grip strength is associated with a range of adverse health outcomes and an accelerated decline in grip strength confers an even greater risk. The factors associated with change in grip strength in mid-life remain to be fully determined. Methods We used data from 44,315 UK Biobank participants who had grip strength measured at baseline (2006-10) and a subsequent visit approximately nine years later. At baseline, participants' long-term conditions (LTCs) were categorised against a hierarchy, with multimorbidity characterised by the number of LTC categories. Lifestyle factors were assessed. Change in grip strength was grouped into four patterns: decline, stable low, stable high or reference (no change or increase) and used as the outcome in multinomial logistic regression. Results Most LTC categories were associated with adverse patterns of change in grip strength (stable low and/or decline): for example, musculoskeletal/trauma conditions were associated with an increased risk of the stable low pattern (Relative Risk Ratio [RRR] = 1.63; 95% confidence interval [CI]: 1.49-1.79). Multimorbidity and lifestyle factors had independent associations with grip strength change. Those with 3+ categories of LTCs were more likely to experience decline in grip strength (RRR = 1.18; 95% CI: 1.08-1.28) compared to those with none. Low physical activity was associated with adverse patterns of grip strength, while raised body mass index (BMI) had divergent associations. Conclusions Individuals living with multimorbidity and those with lifestyle risk factors such as low physical activity are at increased risk of low muscle strength and the loss of strength over time. [ABSTRACT FROM AUTHOR]

Purpose: To investigate strength and power development in elite rugby players during the different phases of a professional season. Methods: Sixteen professional rugby union athletes from an English premiership team were monitored for measures of lower-body peak force, force at 50 ms, force at 100 ms (all isometric squat), and power (explosive hack squat). Athletes were assessed at the start of preseason (Tl), postpreseason (T2), midway through the competitive season (T3), and at the end of the competitive season (T4). Effect-size (ES) statistics with magnitude-based inferences were calculated to interpret differences in physical performance between the different stages of the season. Results: Very likely beneficial increases in force at 50 ms (+16%, ES = 0.75 ± 0.4) and 100 ms (+14%, ES = 0.63 ± 0.4) were observed between T1 and T2. A likely beneficial increase in power was observed between T2 and T3 (+4%, ES = 0.31 ± 0.2). Between T3 and T4, decreases in force at 50 ms (-6%, ES = -0.39 ± 0.3) and 100 ms (-9%, ES - -0.52 ± 0.4) occurred, while peak force and power were maintained. Over the full season (T1-T4) clear beneficial increases in all measures of strength and power were identified. Conclusions: Meaningful increases in strength and power can be achieved in professional English premiership rugby players over a full playing season. The greatest opportunity for strength and power development occurs during pre- to midseason phases, while these measures are maintained or decrease slightly during the latter stages of a season. [ABSTRACT FROM AUTHOR]

To investigate reasons for the age-related reduction in physical function, we determined the relationships between muscle size, strength, and power with 6-min walk distance (6MWD) and timed up-and-go performance in 49 young (23 ± 3.1 years) and 66 healthy, mobile older adults (72 ± 5 years). While muscle mass, determined by DXA and MRI, did not correlate with performance in the older adults, power per body mass, determined from a countermovement jump, did correlate. The 40% lower jumping power observed in older adults (p < .05) was due to a lower take-off velocity, which explained 34% and 42% of the variance in 6MWD in older women and men, respectively (p < .01). The lower velocity was partly attributable to the higher body mass to maximal force ratio, but most was due to a lower intrinsic muscle speed. While changes in muscle function explain part of the age-related reduction in functional performance, ~60% of the deficit remains to be explained. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of simulated soccer on the hamstrings eccentric torque-angle profile and angle of peak torque (APTeccH), and on the hamstrings:quadriceps torque ratio at specific joint angles (ASHecc:Qcon). Methods: The authors assessed dominant-limb isokinetic concentric and eccentric knee flexion and concentric knee extension at 120°/s in 9 semiprofessional male soccer players immediately before and after they completed the Loughborough Intermittent Shuttle Test (LIST). Results: The LIST resulted in significant decreases in eccentric hamstrings torque at 60°, 50°, and 10° and a significant (21.8%) decrease in ASHecc:Qcon at 10° (P < .05). APTeccH increased from 7.1° ± 1.0° to 18.8° ± 4.2° (P < .05). Eccentric hamstrings peak torque significantly declined from 185.1 ± 70.4 N·m pre-LIST to 150.9 ± 58.5 N·m post-LIST (P = .002), but there were no significant changes in hamstrings or quadriceps concentric peak torque (P = .312, .169, respectively). Conclusions: Simulated soccer results in a selective loss of eccentric hamstrings torque and hamstrings-to-quadriceps muscle balance at an extended joint position and a shift in the eccentric hamstrings APT to a shorter length, changes that could increase vulnerability to hamstrings injury. These findings suggest that injury-risk screening could be improved by evaluating the eccentric hamstrings torque-angle profile and hamstrings strength-endurance and that the development of hamstrings fatigue resistance and long-length eccentric strength may reduce injury incidence. [ABSTRACT FROM AUTHOR]

PURPOSE: To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming. METHODS: Twenty national-level junior swimmers (10 male and 10 female, 16 ± 1 y, 171 ± 5 cm, 63 ± 4 kg) participated in the study. Group allocation (intervention [n = 10], control [n = 10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function. RESULTS: Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (-2.0%; 90% confidence interval -3.8 to -0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1-16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7-33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction. CONCLUSION: This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance. [ABSTRACT FROM AUTHOR]

CONTEXT: Hamstring injury-risk assessment has primarily been investigated using isokinetic dynamometry. However, practical issues such as cost and availability limit the widespread application of isokinetics for injury-risk assessment; thus, field-based alternatives for assessing eccentric hamstring strength are needed. OBJECTIVE: The aim of this study was to investigate the validity of the angle achieved during Nordic hamstring lowers (break-point angle) as a field-based test for eccentric hamstring strength. DESIGN: Exploratory study. SETTING: Laboratory. PARTICIPANTS: Sixteen male (n = 7) and female (n = 9) soccer players (mean ± SD age 24 ± 6 y, height 1.77 ± 0.12 m, and body mass 68.5 ± 16.5 kg) acted as subjects for the study. MAIN OUTCOME MEASURES: The authors explored relationships between the Nordic break-point angle (the point at which the subject can no longer resist the increasing gravitational moment during a Nordic hamstring lower) measured from video and isokinetic peak torque and angle of peak torque of right- and left-knee flexors. RESULTS: The results revealed a meaningful relationship between eccentric knee-flexor peak torque (average of right and left limbs) and the Nordic break-point angle (r = -.808, r2 = 65%, P < .00001). However, there was a weak relationship observed (r = .480, r2 = 23%, P = .06) between break-point angle and the angle of peak torque (average of right and left limbs). CONCLUSIONS: The results suggest that the break-point angle achieved during Nordic hamstring lowers could be used as a field-based assessment of eccentric hamstring strength. [ABSTRACT FROM AUTHOR]

The potential ergogenic effects of vitamin D (vitD) in high performing athletes has received considerable attention in the literature and media. However, little is known about non-supplemented university athletes and students residing at a higher latitude. This study aimed to investigate the effects of vitD (biochemical status and dietary intake) on exercise performance in UK university athletes and sedentary students. A total of 34 athletes and 16 sedentary controls were studied during the spring and summer months. Serum vitD status and sunlight exposure were assessed using LC-MS/MS and dosimetry, respectively. Muscular strength of the upper and lower body was assessed using handgrip and knee extensor dynamometry (KE). Countermovement jump (CMJ) and aerobic fitness were measured using an Optojump and VO2max test, respectively. Statistical analysis was performed using paired/ independent t-tests, ANCOVA and Pearson/ Spearman correlations, depending on normality. VitD status increased significantly over the seasons, with athletes measuring higher status both in spring (51.7±20.5 vs. 37.2±18.9 nmol/L, p = 0.03) and summer (66.7±15.8 vs 55.6±18.8 nmol/L, p = 0.04) when compared to controls, respectively. Notably, 22% of the subjects recruited were vitD deficient during the spring term only (<25nmol/L, n 9). Subjects with 'insufficient' vitD status (<50nmol/L) elicited significantly lower CMJ when contrasted to the vitD 'sufficient' (>50nmol/l) group (p = 0.055) and a lower VO2 max (p = 0.05) in the spring and summer term (p = 0.05 and p = 0.01, respectively). However, an ANCOVA test showed no significant difference detected for either CMJ or VO2max following adjustments for co-variates. In conclusion, we provide novel information on the vitD status, dietary intake, physical fitness and sunlight exposure of UK young adults across two separate seasons, for which there is limited data at present. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to explore, via an online survey, how therapists assess, diagnose and manage hemiplegic shoulder pain (HSP) in the United Kingdom. The objectives were to explore (1) how therapists assessed HSP, (2) what the aims of therapy were, (3) what interventions therapists used, (4) what outcome measures therapists used, (5) what training of HSP therapists had, and (6) what barriers therapists experienced in the management of HSP. Methods: An online survey was distributed to physiotherapists (PTs) and occupational therapists (OTs) working in stroke rehabilitation via professional bodies' interest groups. Results: Sixty‐seven responses were received: 40 (60%) were PTs and 27 (40%) were OTs. Therapists routinely screened for HSP (n = 59, 89%). When HSP was assessed, 33 (50%) spent <10 min and 34 (50%) spent >10 min on assessment. Patient‐reported pain was used for assessment of HSP by 66 (99%) of respondents. Frequent interventions included positioning (n = 62, 94%), posture re‐education (n = 57, 86%), and range of motion exercises (n = 55, 83%). Range of movement was used as an outcome measure by 31 (47%). Sixty (91%) respondents reported receiving training in HSP management. Time constraints (n = 41, 62%) and lack of diagnosis of HSP (n = 33, 54%) were identified as barriers to providing appropriate care to people with HSP Conclusion: Study findings showed varied practice in the assessment and treatment for HSP and indicate that time constraints are a considerable barrier to the management of these patients. Further research is required to establish best practice which may help improve outcomes and care for people with poststroke shoulder pain. [ABSTRACT FROM AUTHOR]

The aims of this study were to quantify the effects of spinal mobilization on force production, failure point, and muscle activity of the hamstrings during the Nordic hamstring exercise (NHE), and to explore individual differences in responses. In a replicated randomized crossover trial, 24 asymptomatic, recreationally active men (age [mean ± standard deviation]: 27 ± 6 years; body mass: 82 ± 17 kg; height: 181 ± 8 cm) completed 2 standardized intervention trials (L4/5 zygapophyseal mobilizations) and 2 control trials. The failure point of the NHE was determined with 3D motion capture. Peak force, knee flexor torque, and electromyography (EMG) of the biceps femoris were measured. Data analyses were undertaken to quantify mean intervention response and explore any individual response heterogeneity. Mean (95% confidence interval) left-limb force was higher in intervention than in control trials by 18.7 (4.6-32) N. Similarly, right-limb force was higher by 22.0 (3.4-40.6) N, left peak torque by 0.14 (0.06-0.22) N • m, and right peak torque by 0.14 (0.05-0.23) N • m/kg. Downward force angle was decreased in intervention vs control trials by 4.1° (0.5°-7.6°) on the side of application. Both peak EMG activity (P =.002), and EMG at the downward force (right; P =.020) increased in the intervention condition by 16.8 (7.1-26.4) and 8.8 (1.5-16.1) mV, respectively. Mean downward acceleration angle changed by only 0.3° (−8.9° to 9.4°) in intervention vs control trials. A clear response heterogeneity was indicated only for right force (Participant × Intervention interaction: P =.044; response heterogeneity standard deviation = 34.5 [5.7-48.4] N). Individual response heterogeneity was small for all other outcomes. After spinal mobilization, immediate changes in bilateral hamstring force production and peak torque occurred during the NHE. The effect on the NHE failure point was unclear. Electromyographic activity increased on the ipsilateral side. Response heterogeneity was generally similar to the random trial-to-trial variability inherent in the measurement of the outcomes. [ABSTRACT FROM AUTHOR]