Autoregulation in resistance training : addressing the inconsistencies

Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties

International Society of Sports Nutrition Position Stand: Nutritional recommendations for single-stage ultra-marathon; training and racing

Background. In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~60% of energy intake, 5 – 8 g⸱kg−1·d−1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~1.6 g·kg−1·d−1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g⸱kg−1·d−1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150 - 400 kcal⸱h−1 (carbohydrate, 30 – 50 g⸱h−1; protein, 5 – 10 g⸱h−1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450 – 750 mL⸱h−1 (~150 – 250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., >575 mg·L−1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety

Bovine herpesvirus 1 abortion: current prevalence in the United Kingdom and evidence of hematogenous spread within the fetus in natural cases

9 páginas.While Bovine herpesvirus 1 (BoHV-1) has been known as a cause of bovine abortion for nearly 50 years, information is limited on the current prevalence of BoHV-1 abortion in the United Kingdom, or about the mode of virus dissemination to cause infection of the fetus. The present study aimed to investigate these issues by surveying the prevalence of BoHV-1 in abortion cases in the United Kingdom, and comparing diagnostic methods to determine which are most efficient in BoHV-1–induced abortion. Where BoHV-1 DNA was detected, viral load was compared in fetal tissues, using real-time polymerase chain reaction (PCR), supported by histopathology and immunohistochemistry (IHC) to investigate virus dissemination in bovine abortions. A total of 400 U.K. bovine abortion cases were studied; PCR detected BoHV-1 nucleic acids in 10 cases, suggestive histopathological lesions were observed in 8, and positive IHC staining was observed in 9. In routine diagnosis, BoHV-1 was identified in 2 of these cases, highlighting the utility of using molecular diagnostic tests such as real-time PCR to achieve high sensitivity in potentially autolyzed tissues. The study of different fetal samples showed the highest viral load in the liver, along with severe multifocal necrotic hepatitis, suggesting either a clear tropism of the virus for this organ or that it is the first location to be reached in the fetus. Presence of viral antigen in endothelial cells of the placenta, brain, or heart suggest a hematogenous spread of virus from placenta to the liver, through the umbilical vein, and then to the rest of the organs via fetal blood vessels.Moredun Scientific Limited Scottish GovernmentPeer reviewe

The effects of a multi-ingredient supplement on markers of muscle damage and inflammation following downhill running in females

BACKGROUND: The effects of a multi-ingredient performance supplement (MIPS) on markers of inflammation and muscle damage, perceived soreness and lower limb performance are unknown in endurance-trained female athletes. The purpose of this study was to determine the impact of MIPS (NO-Shotgun®) pre-loaded 4 weeks prior to a single-bout of downhill running (DHR) on hsC-Reactive Protein (hsCRP), interleukin (IL)-6, creatine kinase (CK), muscle soreness, lower limb circumferences and performance. METHOD: Trained female runners (n = 8; 29 ± 5.9 years) (VO(2max): ≥ 50 ml(-1).kg(-1).min(-1), midfollicular phase (7-11 days post-menses) were randomly assigned in a double-blind manner into two groups: MIPS (n = 4) ingested one serving of NO Shotgun daily for 28 days prior to DHR and 30 min prior to all post-testing visits; Control (CON) (n = 4) consumed an isocaloric maltodextrin placebo in an identical manner to MIPS. hsCRP, IL-6, CK, perceived soreness, limb circumferences, and performance measures (flexibility, squat jump peak power) were tested on 5 occasions; immediately before (PRE), immediately post-DHR, 24, 48 and 72 h post-DHR. RESULTS: There were main effects of time for CK (p = 0.05), pain pressure threshold (right tibialis anterior (p = 0.010), right biceps femoris (p = 0.01), and left iliotibial band (ITB) (p = 0.05) across all time points), and maximum squat jump power (p = 0.04). Compared with 24 h post-DHR, maximum squat jump power was significantly lower at 48 h post-DHR (p = 0.05). Lower body perceived soreness was significantly increased at 24 h (p = 0.02) and baseline to 48 h (p = 0.02) post DHR. IL-6 peaked immediately post-DHR (p = 0.03) and hsCRP peaked at 24 h post-DHR (p = 0.06). Calculation of effect sizes indicated a moderate attenuation of hsCRP in MIPS at 72 h post-DHR. CONCLUSIONS: Consumption of MIPS for 4 weeks prior to a single bout of DHR attenuated inflammation three days post, but did not affect perceived soreness and muscle damage markers in endurance trained female runners following a single bout of DHR