Plasma C-terminal agrin fragment concentrations across adulthood: Reference values and associations with skeletal muscle health.

BACKGROUND: Increasing interest surrounds the utility of blood-based biomarkers for diagnosing sarcopenia. C-terminal agrin fragment (CAF), a marker of neuromuscular junction stability, is amongst the most promising candidates; however, a dearth of reference data impedes the incorporation of its use in public health settings. This study aimed to establish reference values for plasma CAF concentrations across adulthood in a large, well-characterized cohort of healthy adults; and comprehensively examine the association between plasma CAF levels and skeletal muscle health. METHODS: One thousand people aged between 18 and 87 years took part in this study (mean age = 50.4 years; 51% females). Body composition and muscle strength were examined using DXA and hand dynamometry. Plasma CAF concentrations were measured, in duplicate, using commercially available ELISA kits. Sarcopenia and individual sarcopenia signatures [low skeletal muscle index (SMI) only/low grip strength only] were classified using the EWGSOP2 algorithm. RESULTS: Detailed reference CAF values, according to sex and age, are presented. A significant but modest age-related increase in plasma CAF concentration was observed (P = 0.018). Across adulthood, CAF concentrations were negatively associated with grip strength and SMI (both P < 0.001). In people ≥50 years old, CAF concentrations were 22.6% higher in those with sarcopenia (P < 0.001), 11.3% higher in those with low SMI (P = 0.006) and 9.6% higher in those with low grip strength (P = 0.0034), compared with controls. People in the highest CAF concentration quartile, had 3.25 greater odds for sarcopenia (95% CI = 1.41-7.49, P = 0.005), 2.76 greater odds for low SMI (95% CI = 1.24-5.22, P = 0.012), and 2.56 greater odds for low grip strength (95% CI = 1.07-5.57, P = 0.037), compared with those in the lowest quartile. People with a CAF Z-score ≥2 had 9.52 greater odds for sarcopenia (95% CI = 3.01-30.05, P < 0.001) compared with a Z-score <1. Plasma CAF concentration had an acceptable level of diagnostic accuracy for sarcopenia (AUC = 0.772, 95% CI = 0.733-0.807, P < 0.001). CONCLUSIONS: The reference values presented herein may guide the clinical interpretation of circulating CAF and help identify people at risk of poor skeletal muscle outcomes for inclusion in therapeutic interventions. Our findings add clarity to existing data, demonstrating a robust relationship between circulating CAF and skeletal muscle integrity in the largest adult cohort to date, and support the use of CAF as an accessible, cost-effective screening tool for sarcopenia. However, further research into the prognostic utility of plasma CAF, and the establishment of normative data from other populations, are urgently needed if routine CAF screening is to be embedded into public healthcare settings.

Grip strength positively correlates with blood pressure in individuals with abnormal adiposity.

Although strong positive correlations exist between grip strength and cardiovascular health, the association between grip strength and blood pressure (BP) is less clear. In this regard, a more precise relationship between grip strength and BP may be revealed by considering adiposity. We examined the association between grip strength and BP in 9424 individuals aged 18-92 years, while controlling for or stratifying by body mass index (BMI) or body fat (BF)%. Grip strength, BP and BF% were determined using dynamometry, sphygmomanometry and dual-energy x-ray absorptiometry. Overall, those with elevated BP had greater grip strength than those with normal BP (39.17 kg vs 38.38 kg, p < 0.001); however, following stratification this was only observed in overweight or obese individuals (42.08 kg vs 41.10 kg, p = 0.003 and 41.34 kg vs 40.03 kg, p = 0.033), and those within the highest BF% tertile (37.95 kg vs 36.52 kg, p < 0.001). Overall, higher grip strength was associated with an increased odds for elevated BP (OR = 1.014, 95% CI = 1.004-1.024, p = 0.004); however, after stratification the increased odds was only observed in overweight or obese individuals (OR = 1.025, 95% CI = 1.010-1.039, p < 0.001 and OR = 1.018, 95% CI = 1.004-1.031, p = 0.010), and those within the highest BF% tertile (OR = 1.036, 95% CI = 1.022-1.051, p < 0.001). Individuals with low grip strength and high BF% had lower odds for elevated BP (OR = 0.514, 95% CI = 0.341-0.775, p = 0.002), whereas those with low grip strength and low BF% had higher odds for elevated BP (OR = 2.162, 95% CI = 1.026-4.555, p = 0.043). Our findings show that higher grip strength is related to higher BP in overweight or obese individuals, or those with a high BF%. Having a BMI < 25 kg/m2 or lower BF% may neutralise this association.

Handgrip strength asymmetry as a new biomarker for sarcopenia and individual sarcopenia signatures.

BACKGROUND: Although handgrip strength (HGS) asymmetry has clinical screening utility, its relevance to sarcopenia is unknown. This study examined the relationship between HGS asymmetry and sarcopenia signatures, and explored the relevance of circulating neural/neuromuscular markers. METHODS: 9403 individuals aged 18-92 years participated in this study. Maximal HGS and skeletal muscle index (SMI) were determined using hand dynamometry and DXA. Sarcopenia was diagnosed upon the presence of low HGS and low SMI, according to cohort-specific thresholds. Plasma biomarkers were measured by ELISA in a sub-group of 269 participants aged 50-83 years. Asymmetry was determined as the highest recorded HGS divided by the highest recorded HGS of the opposite hand. Individuals with a ratio > 1.10 were classified as having asymmetrical HGS. RESULTS: Subjects with asymmetrical HGS had significantly lower SMI (7.67 kg/m2 vs 7.71 kg/m2, p = 0.004) and lower HGS (37.82 kg vs 38.91 kg, p < 0.001) than those with symmetrical HGS. In those aged ≥ 50 years asymmetrical HGS was associated with 2.67 higher odds for sarcopenia [95% confidence interval: (CI) = 1.557-4.561, p < 0.001], 1.83 higher odds for low HGS only (CI 1.427-2.342, p < 0.001), and 1.79 higher odds for low SMI only (CI 1.257-2.554, p = 0.001). HGS asymmetry demonstrated acceptable diagnostic accuracy for sarcopenia (AUC = 0.727, CI 0.658-0.796, p < 0.001). Plasma neural cell adhesion molecule concentrations were 19.6% higher in individuals with asymmetrical HGS (185.40 ng/mL vs 155.00 ng/mL, p < 0.001) than those with symmetrical HGS. DISCUSSION: Our findings demonstrate the utility of HGS asymmetry as a screening tool that may complement existing strategies seeking to combat sarcopenia. Biomarker analyses suggest that heightened denervation may be an important aetiological factor underpinning HGS asymmetry.

Contact injuries in field hockey and the potential role for personal protective equipment.

Field hockey is played with sticks and a hard ball. It is fast-paced, with athletes playing together in close proximity. Athletes may be at increased risk of sustaining injuries through contact. The aim of this study was to investigate the epidemiological characteristics of contact injuries in field hockey. Data were collected during the 2017/2018 and 2018/2019 Irish Hockey League seasons. This study included two methods of data collection among male athletes: self-reported injuries and via those reported by the teams' physiotherapists. Injuries were defined as any physical complaint sustained during field hockey, supplemented by medical attention and time-loss injuries. Only contact injuries were included for analysis. Overall, 107 contact injuries were incurred, giving rise to an injury incidence rate of 3.1/1000 h, and accounting for 33.1% of all injuries. Athletes had an absolute risk of 0.372 of sustaining a contact injury. Contusions (48.6%) were the most common type of contact injury, while injuries to the head/face (20.6%) were the most frequently reported location. Contact injuries represent an important proportion of all injuries. Rule changes to mandate the use of personal protective equipment in field hockey may assist in reducing the absolute risk and severity of contact injuries in field hockey.

Genes encoding agrin (AGRN) and neurotrypsin (PRSS12) are associated with muscle mass, strength and plasma C-terminal agrin fragment concentration.

Although physiological data suggest that neuromuscular junction (NMJ) dysfunction is a principal mechanism underpinning sarcopenia, genetic studies have implicated few genes involved in NMJ function. Accordingly, we explored whether genes encoding agrin (AGRN) and neurotrypsin (PRSS12) were associated with sarcopenia phenotypes: muscle mass, strength and plasma C-terminal agrin fragment (CAF). PhenoScanner was used to determine if AGRN and/or PRSS12 variants had previously been implicated with sarcopenia phenotypes. For replication, we combined genotype from whole genome sequencing with phenotypic data from 6715 GenoFit participants aged 18-83 years. Dual energy X-ray absorptiometry assessed whole body lean mass (WBLM) and appendicular lean mass (ALM), hand dynamometry determined grip strength and ELISA measured plasma CAF in a subgroup (n = 260). Follow-up analyses included eQTL analyses, carrier analyses, single-variant and gene-burden tests. rs2710873 (AGRN) and rs71608359 (PRSS12) associate with muscle mass and strength phenotypes, respectively, in the UKBB (p = 8.9 × 10-6 and p = 8.4 × 10-6) and GenoFit cohort (p = 0.019 and p = 0.014). rs2710873 and rs71608359 are eQTLs for AGRN and PRSS12, respectively, in ≥ three tissues. Compared to non-carriers, carriers of rs2710873 had 4.0% higher WBLM and ALM (both p < 0.001), and 9.5% lower CAF concentrations (p < 0.001), while carriers of rs71608359 had 2.3% lower grip strength (p = 0.034). AGRN and PRSS12 are associated with muscle strength and mass in single-variant analyses, while PRSS12 has further associations with muscle strength in gene-burden tests. Our findings provide novel evidence of the relevance of AGRN and PRSS12 to sarcopenia phenotypes and support existing physiological data illustrating the importance of the NMJ in maintaining muscle health during ageing.

Winter breaks: How do they affect injuries in field hockey?

OBJECTIVES: The Irish Hockey League (IHL) introduced an eight-week winter break for the first time in the 2018/2019 season. We evaluated the effects of this eight-week break by comparing injury outcome metrics in the 2018/2019 (winter break) season and the 2017/2018 (no winter break) season. DESIGN: Prospective cohort study. METHODS: Each season was split into three distinct periods: period one consisted of the first nine weeks of each season; period two, weeks ten to 18; and period three, the final weeks. For the 2018/2019 season, the winter break was implemented in period two (weeks 10 to18). Relative risk with 95 % CI and injury incidence (1000h) were compared across the two seasons. RESULTS: Overall, 173 and 150 injuries we incurred during the 2017/2018 (no winter break) and 2018/2019 (winter break season) seasons respectively. Compared to 2017/2018 season, total injury incidence rate, injury severity, and injury burden were all significantly higher in period three during the 2018/2019 season (i.e., following the winter break). Furthermore, injured athletes had a 2.5-times higher relative risk of sustaining an injury after the winter break. Relative risks of 15.3 and 21.4 were observed for lower back injuries and fractures after the winter break, when compared with no break. CONCLUSIONS: Although fewer injuries were incurred during the 2018/2019 season, significantly more injuries were sustained in the period after the implementation of the winter break when compared to the corresponding period during the 2017/2018 season.

The knowledge and attitudes of field hockey athletes to injury, injury reporting and injury prevention: A qualitative study.

OBJECTIVES: Researchers have often struggled to successfully implement injury prevention strategies in real-world practice. This is despite such strategies proving successful in reducing overall injury incidence and burden. It has been hypothesised that this may be because the behavioural and contextual factors related to sports injury are not fully understood. Such factors stem from multiple key stakeholders, including the athlete. The primary aim of this study was to investigate athletes' knowledge and attitudes towards injury, injury reporting and prevention, as well as some of the barriers that may impact the future implementation of prevention strategies. DESIGN: Qualitative; with semi-structured interviews following an interpretivist approach. METHODS: Twenty-two field hockey athletes, playing in the top-tier Irish Hockey League were interviewed. Data were analysed using reflexive thematic analysis, with three general dimensions containing six higher-order themes. RESULTS: The findings highlighted that athletes have a varied understanding of injury, which tends to improve with experience. The reporting of injuries by athletes to members of the coaching staff was relatively poor. This may be due to limited resources and supports available to athletes which also cause challenges to injury prevention. CONCLUSIONS: Future injury prevention strategies in field hockey need to account for athletes' varied understanding of what constitutes an injury. Furthermore, policy changes to influence potential barriers to injury may assist in preventing or reducing the number of injuries being sustained by athletes.

Plasma neurofilament light levels associate with muscle mass and strength in middle-aged and older adults: findings from GenoFit.

BACKGROUND: Efforts to enhance diagnostic measures for sarcopenia have led to an increased focus on the screening utility of blood-based biomarkers. In this regard, circulating neurofilament light chain (NfL) levels are a potent indicator of axonal damage and have been linked with several neurological disorders. However, despite the strong neurogenic contribution to skeletal muscle health, no studies have explored the relevance of NfL concentrations to sarcopenia. With that in mind, this study aimed to examine the association between plasma NfL concentration and sarcopenic domains. METHODS: Three hundred adults aged between 50 and 83 years participated to this study (male participants, n = 150; mean age: 64.2 ± 8.7 years and female participants, n = 150; mean age: 63.9 ± 8.3 years). Body composition was assessed using dual-energy X-ray absorptiometry, and a skeletal muscle index (SMI) was calculated. Muscle strength was assessed with hand dynamometry. Sarcopenia was classified using the European Working Group on Sarcopenia in Older People criteria. Plasma NfL concentration was determined using a highly sensitive, enzyme-linked immunosorbent assay. RESULTS: Neurofilament light chain levels were associated with grip strength and SMI (P = 0.005 and P = 0.045, respectively) and were significantly elevated in sarcopenic individuals, compared with non-sarcopenic participants (P < 0.001). Individuals with pre-sarcopenia (either low grip strength or low SMI) had significantly higher NfL levels, compared with healthy controls (P = 0.001 and P = 0.006, respectively). Male participants with either low grip strength or low SMI had significantly raised NfL levels (P = 0.006 and P = 0.002, respectively), while in female participants, NfL concentrations were significantly elevated only in those with low grip strength (P = 0.049). NfL concentration displayed acceptable diagnostic accuracy for sarcopenia (area under the curve = 0.726, P < 0.001). CONCLUSIONS: Our study clearly demonstrates the indicative pertinence of circulating NfL levels to sarcopenic domains, supporting its potential use as a biomarker of sarcopenia. More studies are needed, however, to further illuminate the diagnostic value of circulating NfL. Future research should explore whether NfL levels are more powerfully linked with muscle strength than mass and whether sex mediates the relevance of NfL concentrations to sarcopenic phenotypes.

Coaches' attitudes to injury and injury prevention: a qualitative study of Irish field hockey coaches.

Translating injury prevention research into practice has been challenging, which may be due to a poor understanding of the contextual factors influencing the occurrence of injury. Coaches are key figure in sporting environments and hold pivotal roles in preventing injury. Therefore, the aim of this study was to investigate the attitudes of field hockey coaches to injury and injury prevention. Thirteen field hockey coaches from the amateur Irish Hockey League were interviewed. Reflexive thematic analysis led to three general dimensions comprised five higher-order themes, categorised from 16 lower-order themes. Coaches had positive beliefs regarding the benefits of injury prevention over injury management. However, they lacked the necessary knowledge and skills to successfully implement injury prevention strategies with players. Coaches recognised the importance of empowering players to self-manage training loads to promote injury prevention but acknowledged the need to protect younger players from increased loads. Many barriers to injury prevention were not controllable by coaches including fixture congestion and poor structuring of the sport's domestic calendar. While coaches can play a key role in the implementation of injury prevention strategies, there is also a requirement to examine how system level barriers to injury prevention can be reduced.

The incidence of injury in male field hockey players: A systematic review and meta-analysis.

OBJECTIVE: Few studies have investigated injury incidence in field hockey. The aim of this systematic review was to determine the incidence and characteristics of injury in male field hockey athletes. DESIGN: Prognosis systematic review with meta-analysis. LITERATURE SEARCH: MEDLINE via PubMed; EMBASE via Ovid; CINAHL via EBSCO; SPORTDiscus; and Web of Science were searched. STUDY SELECTION CRITERIA: Prospective studies and retrospective studies employing video analysis, written in English and published in peer-reviewed journals, expressing the incidence of injury in male field hockey athletes were included. Studies must have been of a duration of a minimum one season or one tournament. Studies were screened by two authors, assessing the eligibility of each record. Following selection of the studies, data were extracted by the two authors. DATA SYNTHESIS: Levels of heterogeneity were assessed in aggregate data using the I2 statistic. RESULTS: In total, 1722 records were identified. Twelve studies were included in the review. Injury incidence ranged from 4.5 to 57.9/1000h (I2 = 98.5%). Nine studies were undertaken in tournament settings, with the remaining three conducted in club-based athletes in season-long settings. When a medical attention definition was used, there was a pooled incidence rate of 48.1/1000h, all in tournament studies. Contusions and muscle strains were the most frequently reported injury types, while the lower limb was the most common site of injury. Contact injuries were most common in tournament-based studies, while non-contact was more common in season-long studies. CONCLUSION: Prospective, season-long epidemiological studies investigating injury incidence in field hockey are lacking.

Grip strength performance from 9431 participants of the GenoFit study: normative data and associated factors.

Weak grip strength is a strong predictor of multiple adverse health outcomes and an integral diagnostic component of sarcopenia. However, the limited availability of normative data for certain populations impedes the interpretation of grip performance across adulthood. This study aimed to establish normative data and low grip strength thresholds in a large adult population, and to examine associations between grip strength and clinically relevant health variables. A total of 9431 adults aged between 18 and 92 years participated in this study (mean age: 44.8 ± 13.4 years; 57% females). Grip strength, body composition, and cardiorespiratory (CR) fitness were assessed using hand dynamometry, dual-energy x-ray absorptiometry and physical work capacity tests, respectively. Low grip strength was established according to criteria of the European Working Group on Sarcopenia in Older People. Normative data and t-scores, stratified by sex and age groups, are presented. Grip performance was associated with lean mass, skeletal muscle index (SMI), fat mass, CR fitness, bone mineral density (BMD), android/gynoid ratio, disease prevalence and physical activity levels (all p < 0.001) after controlling for multiple potential confounders. Individuals with weak grip strength had lower lean mass, SMI, CR fitness (all p < 0.001) and BMD (p = 0.001), and higher disease prevalence (p < 0.001), compared to healthy controls, although sex-specific differences were observed. Grip strength has practical screening utility across a range of health domains. The normative data and grip strength thresholds established in this study can guide the clinical interpretation of grip performance and facilitate timely therapeutic strategies targeting sarcopenia.

A Comparison of Peak Intensity Periods across Male Field Hockey Competitive Standards.

This investigation aimed to compare the international level peak intensity period of male field hockey players to those experienced during professional and amateur club hockey match play. Twenty-seven players from an international squad were monitored for all activity relating to field hockey over three seasons. The peak intensity period, of 3 min duration, was extracted from match play files for international and club matches. Club matches were categorised by league standard-professional vs. amateur. The output for the peak intensity period, within positions, was compared using linear mixed models (LMMs) and post hoc pairwise comparisons. Significance levels were set as p < 0.05 and Cohen's d was utilised for effect sizes. Competition level had a main effect on relative total distance (p < 0.05) and significant interaction effects were found between competition level and position (p < 0.05). Midfielders competing in amateur leagues and international match play completed less relative total distance than those who compete in professional leagues (-47.88 m/min, p < 0.05), (-46.06 m/min, p < 0.05) with large effect sizes reported. No other position displayed significant differences for peak periods. Match play in professional leagues provide opportunities for midfielders to experience peak intensity periods of a greater magnitude than international match play.

Plasma C-Terminal Agrin Fragment as an Early Biomarker for Sarcopenia: Results From the GenoFit Study.

Barriers associated with direct muscle quantification have prevented a consistent implementation of therapeutic measures for sarcopenia. Recently, the relevance of circulating C-terminal agrin fragment (CAF) as an accessible screening method alternative for sarcopenia has gained credence. Accordingly, this study aimed to verify the pertinence of plasma CAF as a biomarker for sarcopenia. Three hundred healthy adults aged between 50 and 83 years took part in this study. Sarcopenia was diagnosed according to the European Working Group on Sarcopenia in Older People criteria. Body composition was assessed using dual-energy x-ray absorptiometry, while muscle strength was examined using hand dynamometry. Plasma CAF concentrations were determined using a commercially available ELISA kit. CAF concentrations were significantly associated with appendicular lean mass (ALM), but not grip strength (p = .028, p = .575, respectively). Plasma CAF concentrations were significantly elevated in sarcopenic individuals compared to nonsarcopenic (p < .001). Overall, individuals with low grip strength or low ALM displayed significantly higher CAF levels compared to healthy controls, after adjusting for age and body mass index (p = .027, p = .003, respectively). In males, those with low grip strength or low ALM had significantly elevated CAF levels (p = .039, p = .027, respectively), while in females, only those with low ALM had significantly raised CAF concentrations, compared to healthy controls (p = .035). Our findings illuminate the potential relevance of CAF as an accessible biomarker for skeletal muscle health. CAF determination may enhance clinical practice by facilitating more widespread treatment strategies for sarcopenia. Nevertheless, future research is needed to confirm the diagnostic pertinence of CAF concentrations in screening for sarcopenia.

The burden of injury in field hockey: A secondary analysis of prospective cohort data.

Most studies report injuries based upon their incidence rate, or the number of injuries which occur in a sport per unit of time. While this is recommended across numerous consensus statements on reporting injury data in sport, it may be of benefit to consider injury burden also. Reporting injuries as the duration of injury per 1000 exposure hours highlights those injuries which will likely cause greater disruption within a team. Therefore, the primary aim of this study was to report the burden of injury in field hockey. This secondary analysis of epidemiological data employed two methods of data collection: self-reported through an online reporting software, and through contact with the team physiotherapist. Athletes reported injury-related symptoms for 4170 days in total, giving rise to an injury burden of 121.0/1000 h, of which 61.4/1000 h were days lost through injury. Injuries to the hamstring, as well as muscle strain injuries, caused the most significant injury burden in athletes (22.6 and 35.8/1000 h respectively). Reporting injuries as the duration of injuries per 1000 hours highlights those injuries which cause the most significant disruption within a squad. Future injury prevention strategies in field hockey should prioritize the injuries which are most burdensome.

Strength training and gross-motor skill exercise as interventions to improve postural control, dynamic functional balance and strength in older individuals.

BACKGROUND: Loss of balance control is commonly experienced by older individuals. Despite the large amount of research on the effects of exercise on balance the optimal exercise regime is yet to be identified. Most studies have concentrated on strength training due to associations between muscle weakness, balance disfunction and fall risk. The effects of gross-motor skill exercise for balance and postural control have been less investigated. The study aimed to compare the effectiveness of strength training (STT) and gross-motor skill exercise (GMT) on static postural control, dynamic functional balance and strength in healthy older individuals. METHODS: Thirty-eight individuals (65-85 years) participated to GMT or STT for 12 weeks, twice weekly. They were tested pre- and post-training for postural control (Romberg and Tandem positions on a force platform), dynamic functional balance (maximal walking speed in balance-challenging conditions), maximal isometric handgrip strength, maximal knee flexor and extensor strength. RESULTS: Improvements were observed in static postural balance (tandem position, P<0.05, -1.07 mm/s), walking speed (hurdles P<0.01, +0.08 m/s; narrow path P<0.05, +0.07 m/s; picking up P<0.01, +0.07 m/s) knee extensor strength (P<0.001, +10.9 Nm); knee flexor strength improved significantly in the SST group only (P<0.001, +13.9 Nm). There was no correlation between changes in strength and balance. CONCLUSIONS: Static postural balance and dynamic functional balance in healthy elderly may be improved through exercise targeting either muscular strength or coordination, agility and mobility. The present study helps fill the gap in research on gross-motor skill exercise and proposes a suitable exercise alternative to strength for managing static and dynamic balance decline.

Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals.

BACKGROUND: There is a paucity of reliability data for walking speed tests in complex conditions to assess functioning in healthy older individuals. AIMS: To evaluate the absolute intra- and intertest reliability of walking speed performed in basic and complex conditions in healthy older individuals. METHODS: Fifty-two men and women of mean age 69.7 ± 3.2 years were tested for habitual and maximal walking speed. Maximal speed was also assessed under different conditions, including walking on a path of reduced width; picking up objects; stepping over hurdles; stepping over hurdles wearing sunglasses and finally, carrying a box. Two testing sessions (separated by 4 weeks) of two trials each were administered. Reliability was analysed by intra-class correlation coefficient (ICC), minimal detectable change (MDC) and Bland-Altman plots with limits of agreement (LOA). RESULTS: Intrasession ICCs ranged from good to excellent (0.89-0.95) except for picking up objects (0.44). Intersession ICCs were moderate to good (0.60-0.78) and %MDCs were acceptable (14-24%). Bland-Altman plots suggested a good agreement between the two testing sessions at group level (mean differences from - 0.02 to - 0.11 m/s), and limited agreement between testing sessions at individual level (upper LOA from 0.13 to 0.37 m/s and lower LOA from - 0.29 to - 0.49 m/s). CONCLUSIONS: Complex walking speed tests are generally reliable measures displaying good and moderate intra- and inter-session reliability. Such tests seem a more suitable functional assessment tool for heathy older subjects compared with simple walking. Some learning effect may be present and further reliability studies are needed.

Neuromuscular Junction Aging: A Role for Biomarkers and Exercise.

Age-related skeletal muscle degradation known as "sarcopenia" exerts considerable strain on public health systems globally. While the pathogenesis of such atrophy is undoubtedly multifactorial, disruption at the neuromuscular junction (NMJ) has recently gained traction as a key explanatory factor. The NMJ, an essential communicatory link between nerve and muscle, undergoes profound changes with advancing age. Ascertaining whether such changes potentiate the onset of sarcopenia would be paramount in facilitating a timely implementation of targeted therapeutic strategies. Hence, there is a growing level of importance to further substantiate the effects of age on NMJs, in parallel with developing measures to attenuate such changes. As such, this review aimed to establish the current standpoint on age-related NMJ deterioration and consequences for skeletal muscle, while illuminating a role for biomarkers and exercise in ameliorating these alterations. Recent insights into the importance of key biomarkers for NMJ stability are provided, while the stimulative benefits of exercise in preserving NMJ function are demonstrated. Further elucidation of the diagnostic and prognostic relevance of biomarkers, coupled with the therapeutic benefits of regular exercise may be crucial in combating age-related NMJ and skeletal muscle degradation.