Intra-unit reliability and movement variability of submission grappling external load as measured by torso mounted accelerometery.

Submission grappling consists of skills and movements used in combat sports to physically control opponents whilst trying to apply choke holds and joint locks. There is currently no accepted method of monitoring external load in grappling-based sports due to the absence of key variables such as distance, velocity or time. The primary aim of this study was to determine whether PlayerLoad is a reliable variable for measuring external load of submission grappling movements, with a secondary aim of determining the between repetition variance of submission grappling movements. 7 experienced submission grapplers were recruited. Each wore a torso mounted Catapult® Optimeye S5 microelectromechanical systems (MEMS) device and completed 5 repetitions of each of the following: 4 submission techniques; 5 transition techniques; 2 guard pass techniques; 2 takedown techniques. Accumulated PlayerLoad (PLdACC) was recorded as a marker of absolute load, with accumulated PlayerLoad per minute (PLdACC∙min-1) representing relative load. Reliability of each was assessed using intraclass correlation coefficient (ICC(3,1)) (≥ 0.70). Between repetition movement variation was assessed via coefficient of variation with 95% confidence intervals (CV, 95%CI) (acceptable ≤ 15%, good ≤ 10%). PLdACC ICC(3,1) range = 0.78-0.98, with CV range = 9-22%. PLdACC∙min-1 ICC(3,1) range = 0.83-0.98, with CV range = 11-19%. Though several variables displayed CV > 15%, all had 95%CI lower boundaries ≤ 15%. Whilst PlayerLoad was found to be a reliable measure for submission grappling, relatively high CVs across most techniques examined suggest PlayerLoad may not be appropriate for measuring changes in external load for individual movements in submission grappling. However, it may prove a useful tool for monitoring the external load of full, grappling-based, training sessions within an individual.

Effects of exercise and whey protein on muscle mass, fat mass, myoelectrical muscle fatigue and health-related quality of life in older adults: a secondary analysis of the Liverpool Hope University-Sarcopenia Ageing Trial (LHU-SAT).

PURPOSE: To investigate the effects of exercise in combination with, or without, a leucine-enriched whey protein supplement on muscle mass, fat mass, myoelectrical muscle fatigue and health-related quality of life (HR-QOL) in older adults. METHODS: 100 community-dwelling older adults [52% women, age: 69 ± 6 years (mean ± SD)] were randomised to four [Control (C); Exercise (E); Exercise + Protein (EP); Protein (P)] independent groups. E and EP groups completed 16 weeks of exercise [resistance (2 times/week) and functional (1 time/week]. EP and P groups were also administered a leucine-enriched whey protein supplement (3 times/day) based on body weight (1.5 g/kg/day). Muscle and fat mass (bioelectrical impedance analysis), myoelectrical muscle fatigue (surface electromyography) and HR-QOL (WHOQOL-BREF) were measured pre- and post-intervention. RESULTS: At post-intervention, the rectus femoris (E: - 4.8%/min, p = 0.007, ES = 0.86; EP: - 3.3%/min, p = 0.045, ES = 0.58) and bicep femoris (E: - 3.9%/min, p < 0.001, ES = 1.46; EP: - 4.3%/min, p < 0.001, ES = 1.58) muscles became more resistant to fatigue in the E and EP groups, respectively (p < 0.05 versus C). HR-QOL improved in the E group only. Muscle and fat mass did not change (p > 0.05). CONCLUSION: Physical exercise is a potent method to improve myoelectrical muscle fatigue and HR-QOL in older adults. However, leucine-enriched whey protein did not augment this response in those already consuming sufficient quantities of protein at trial enrolment.

Evaluating the progressive cardiovascular health benefits of short-term high-intensity interval training.

PURPOSE: High-intensity training is recognised as a time-efficient way of improving aerobic fitness. However, there is a lack of consensus regarding the temporal nature of adaptation response and which peripheral and cardiac changes occur using the same exercise stimulus and protocol. Therefore, this study aimed to evaluate the progression of vascular and cardiac changes over a 6-week training period. METHODS: Twelve healthy males (age 21 ± 2 years; 42.5 ± 8.3 ml min-1 kg-1) participated in a high-intensity training programme consisting of 1-min sprints, interspersed with 2 min active recovery, 3 days/week for 6 weeks on a cycle ergometer. Cardiac, vascular, blood lipids and VO2max measurements were taken at 0, 3 and 6 weeks and compared against a participant-matched control group (age 21 ± 2 years; 37.7 ± 8.3 ml min-1 kg-1). RESULTS: There was a significant improvement in VO2max (42.5 ± 8.3-47.4 ± 8.5 ml min-1 kg-1; p = 0.009) in the training group and a significant decrease in systolic blood pressure (8%) from 0 to 6 weeks (p = 0.025). There was a small yet significant decrease in ejection fraction and increased end-systolic volume in both groups over time (p = 0.01) with no significant interaction effect (p > 0.05). A between-group difference in peak velocity of early diastolic mitral annular motion was also observed (p = 0.01). No improvements were seen in blood lipid profiles, central arterial stiffness and cardiometabolic risk score. CONCLUSIONS: Six weeks of high-intensity training increases aerobic fitness and is enough to stimulate initial reductions in peripheral pressure, but not sufficient to elicit structural and functional cardiac changes, reduce arterial stiffness or lower CV risk.

Mathematical modelling of metabolic regulation in aging.

The underlying cellular mechanisms that characterize aging are complex and multifaceted. However, it is emerging that aging could be regulated by two distinct metabolic hubs. These hubs are the pathway defined by the mammalian target of rapamycin (mTOR) and that defined by the NAD+-dependent deacetylase enzyme, SIRT1. Recent experimental evidence suggests that there is crosstalk between these two important pathways; however, the mechanisms underpinning their interaction(s) remains poorly understood. In this review, we propose using computational modelling in tandem with experimentation to delineate the mechanism(s). We briefly discuss the main modelling frameworks that could be used to disentangle this relationship and present a reduced reaction pathway that could be modelled. We conclude by outlining the limitations of computational modelling and by discussing opportunities for future progress in this area.

Ventricular structure, function, and focal fibrosis in anabolic steroid users: a CMR study.

PURPOSE: Anabolic steroid (AS) misuse is widespread amongst recreational bodybuilders; however, their effects on the cardiovascular system are uncertain. Our aim was to document the impact of AS use on cardiac structure, function and the presence of focal fibrosis using the gold standard cardiovascular magnetic resonance imaging (CMR). METHODS: A cross-sectional cohort design was utilised with 21 strength-trained participants who underwent CMR imaging of the heart and speckle-tracking echocardiography. Thirteen participants (30 ± 5 years) taking AS for at least 2 years and currently on a "using"-cycle were compared with age and training-matched controls (n = 8; 29 ± 6 years) who self-reported never having taken AS (NAS). RESULTS: AS users had higher absolute left ventricular (LV) mass (220 ± 45 g) compared to NAS (163 ± 27 g; p < 0.05) but this difference was removed when indexed to fat-free mass. AS had a reduced right ventricular (RV) ejection fraction (AS 51 ± 4 % vs. NAS 59 ± 5 %; p < 0.05) and a significantly lower left ventricular E':A' myocardial tissue velocity ratio [AS 0.99(0.54) vs. NAS 1.78(0.46) p < 0.05] predominantly due to greater tissue velocities with atrial contraction. Peak LV longitudinal strain was lower in AS users (AS -14.2 ± 2.7 % vs. NAS -16.6 ± 1.9 %; p < 0.05). There was no evidence of focal fibrosis in any participant. CONCLUSIONS: AS use was associated with significant LV hypertrophy, albeit in-line with greater fat-free mass, reduced LV strain, diastolic function, and reduced RV ejection fraction in male bodybuilders. There was, however, no evidence of focal fibrosis in any AS user.

Exercise referral for drug users aged 40 and over: results of a pilot study in the UK.

OBJECTIVES: To test whether older drug users (aged 40 and over) could be recruited to an exercise referral (ER) scheme, to evaluate the feasibility and acceptability and measure the impact of participation on health. DESIGN: Observational pilot. SETTING: Liverpool, UK. PARTICIPANTS: (1) 12 men and 5 women recruited to ER. (2) 7 specialist gym instructors. OUTCOME MEASURES: Logistic feasibility and acceptability of ER and associated research, rate of recruitment, level of participation over 8 weeks and changes in health. RESULTS: 22 gym inductions were arranged (recruitment time: 5 weeks), 17 inductions were completed and 14 participants began exercising. Attendance at the gym fluctuated with people missing weeks then re-engaging; in week 8, seven participants were in contact with the project and five of these attended the gym. Illness and caring responsibilities affected participation. Participants and gym instructors found the intervention and associated research processes acceptable. In general, participants enjoyed exercising and felt fitter, but would have welcomed more support and the offer of a wider range of activities. Non-significant reductions in blood pressure and heart rate and improvements in metabolic equivalents (METs; a measure of fitness) and general well-being were observed for eight participants who completed baseline and follow-up assessments. The number of weeks of gym attendance was significantly associated with a positive change in METs. CONCLUSIONS: It is feasible to recruit older drug users into a gym-based ER scheme, but multiple health and social challenges affect their ability to participate regularly. The observed changes in health measures, particularly the association between improvements in METs and attendance, suggest further investigation of ER for older drug users is worthwhile. Measures to improve the intervention and its evaluation include: better screening, refined inclusion/exclusion criteria, broader monitoring of physical activity levels, closer tailored support, more flexible exercise options and the use of incentives.

Performance enhancing drug abuse and cardiovascular risk in athletes: implications for the clinician.

The use of performance-enhancing and social drugs by athletes raises a number of ethical and health concerns. The World Anti-Doping Agency was constituted to address both of these issues as well as publishing a list of, and testing for, banned substances in athletes. Despite continuing methodological developments to detect drug use and associated punishments for positive dope tests, there are still many athletes who choose to use performance and image enhancing drugs. Of primary concern to this review are the health consequences of drug use by athletes. For such a large topic we must put in place delimitations. Specifically, we will address current knowledge, controversies and emerging evidence in relation to cardiovascular (CV) health of athletes taking drugs. Further, we delimit our discussion to the CV consequences of anabolic steroids and stimulant (including amphetamines and cocaine) use. These drugs are reported in the majority of adverse findings in athlete drug screenings and thus are more likely to be relevant to the healthcare professionals responsible for the well-being of athletes. In detailing CV health issues related to anabolic steroid and stimulant abuse by athletes we critique current research evidence, present exemplar case studies and suggest important avenues for on-going research. Specifically we prompt the need for awareness of clinical staff when assessing the potential CV consequences of drug use in athletes.

Anabolic steroids and cardiovascular risk.

Recent reports from needle exchange programmes and other public health initiatives have suggested growing use of anabolic steroids (AS) in the UK and other countries. Data indicate that AS use is not confined to body-builders or high-level sportsmen. Use has spread to professionals working in emergency services, casual fitness enthusiasts and subelite sportsmen and women. Although the precise health consequences of AS use is largely undefined, AS use represents a growing public health concern. Data regarding the consequences of AS use on cardiovascular health are limited to case studies and a modest number of small cohort studies. Numerous case studies have linked AS use with a variety of cardiovascular disease (CVD) events or endpoints, including myocardial infarction, stroke and death. Large-scale epidemiological studies to support these links are absent. Consequently, the impact of AS use upon known CVD risk factors has been studied in relatively small, case-series studies. Data relating AS use to elevated blood pressure, altered lipid profiles and ECG abnormalities have been reported, but are often limited in scope, and other studies have often produced equivocal outcomes. The use of AS has been linked to the appearance of concentric left ventricular hypertrophy as well as endothelial dysfunction but the data again remains controversial. The mechanisms responsible for the negative effect of AS on cardiovascular health are poorly understood, especially in humans. Possibilities include direct effects on myocytes and endothelial cells, reduced intracellular Ca2+ levels, increased release of apoptogenic factors, as well as increased collagen crosslinks between myocytes. New data relating AS use to cardiovascular health risks are emerging, as novel technologies are developed (especially in non-invasive imaging) that can assess physiological structure and function. Continued efforts to fully document the cardiovascular health consequences of AS use is important to provide a clear, accurate, public health message to the many groups now using AS for performance and image enhancement.

Anabolic steroid use and longitudinal, radial, and circumferential cardiac motion.

PURPOSE: The purpose of this study was to investigate the effect of anabolic steroid (AS) use on cardiac structure and function and cardiovascular risk factors. METHODS: We recruited 47 strength-trained individuals (male = 46, female = 1), with 28 self-reporting regular AS use and 19 self-reporting never taking AS. Participants underwent assessment of body composition, lipid profiles, blood pressure, 12-lead ECG, and a comprehensive echocardiographic examination incorporating speckle tracking of longitudinal, radial, and circumferential left ventricular (LV) motion. A subgroup of AS users (n = 4) were tested during periods of AS use and abstinence. RESULTS: AS users were heavier (96 ± 15 vs 81 ± 9 kg, P < 0.05), had higher LDL (3.68 ± 0.47 vs 2.41 ± 0.49 mmol·L⁻¹, P < 0.05), and had higher resting HR (79 ± 12 vs 64 ± 13 beats·min⁻¹), although blood pressures did not differ significantly between groups. In AS, LV wall thickness and mass were significantly greater (12 ± 2 vs 11 ± 1 mm and 280 ± 60 vs 231 ± 44 g, respectively, P < 0.05), whereas ejection fractions and peak longitudinal strain ([Latin Small Letter Open E]) were significantly lower (58% ± 8% vs 63% ± 6% and -14.6% ± 2.3% vs -16.9% ± 2.2%, P < 0.05). Indices of global diastolic function were reduced in AS users (E/A, E'/A'). Some diastolic strain rates (ESR and ASR) were altered in AS users. The E/A SR ratio was reduced in the longitudinal plane as well as in the circumferential and radial plane at the basal level (P < 0.05). Basal LV E/A rotation rate was also decreased in AS users (P < 0.05). CONCLUSIONS: AS use is associated with alterations in cardiac structure and function that, allied to poor lipid profiles, represent an increased cardiovascular risk profile.