EFFECT OF SWIM PADDLES ON THE INTRA-CYCLIC VELOCITY VARIATIONS AND ON THE ARM COORDINATION OF FRONT CRAWL STROKE

This study analysed the effect of swimming with hand paddles on arm coordination and velocity pattern. Eight competitive swimmers performed two maximal aerobic tests. The maximal aerobic velocity was significantly higher when swimming with paddles but stroke rate, maximal heart rate and blood lactate values did not differ. The index of coordination (IdC) determined according to Chollet et al. (2000) and the intra-cyclic velocity variations were measured in two 25 m tests, one with and one without swim paddles, at a fixed stroke rate. When swimming with paddles, IdC and the duration of the propulsive phase increased significantly (~~0.0a5n)d the velocity signal frequency spectrum showed fewer harmon~cs (

Human sarcopenia reveals an increase in SOCS-3 and myostatin and a reduced efficiency of Akt phosphorylation

Age-related skeletal muscle sarcopenia is linked with increases in falls, fractures, and death and therefore has important socioeconomic consequences. The molecular mechanisms controlling age-related muscle loss in humans are not well understood, but are likely to involve multiple signaling pathways. This study investigated the regulation of several genes and proteins involved in the activation of key signaling pathways promoting muscle hypertrophy, including GH/STAT5, IGF-1/Akt/GSK-3&beta;/4E-BP1, and muscle atrophy, including TNF&alpha;/SOCS-3 and Akt/FKHR/atrogene, in muscle biopsies from 13 young (20 &plusmn; 0.2 years) and 16 older (70 &plusmn; 0.3 years) males. In the older males compared to the young subjects, muscle fiber cross-sectional area was reduced by 40&ndash;45% in the type II muscle fibers. TNF&alpha; and SOCS-3 were increased by 2.8 and 1.5 fold, respectively. Growth hormone receptor protein (GHR) and IGF-1 mRNA were decreased by 45%. Total Akt, but not phosphorylated Akt, was increased by 2.5 fold, which corresponded to a 30% reduction in the efficiency of Akt phosphorylation in the older subjects. Phosphorylated and total GSK-3&beta; were increased by 1.5 and 1.8 fold, respectively, while 4E-BP1 levels were not changed. Nuclear FKHR and FKHRL1 were decreased by 73 and 50%, respectively, with no changes in their atrophy target genes, atrogin-1 and MuRF1. Myostatin mRNA and protein levels were significantly elevated by 2 and 1.4 fold. Human sarcopenia may be linked to a reduction in the activity or sensitivity of anabolic signaling proteins such as GHR, IGF-1, and Akt. TNF&alpha;, SOCS-3, and myostatin are potential candidates influencing this anabolic perturbation.<br /

Dietary Supplements and Sports Performance: Metabolites, Constituents, and Extracts

This is the fifth in a series of six articles to discuss the major classes of dietary supplements (vitamins; minerals; amino acids; herbs or botanicals; and metabolites/constituents/extracts). The major focus is on efficacy of such dietary supplements to enhance exercise or sports performance

A New Method for Non-Invasive Estimation of Human Muscle Fiber Type Composition

Background: It has been established that excellence in sports with short and long exercise duration requires a high proportion of fast-twitch (FT) or type-II fibers and slow-twitch (ST) or type-I fibers, respectively. Until today, the muscle biopsy method is still accepted as gold standard to measure muscle fiber type composition. Because of its invasive nature and high sampling variance, it would be useful to develop a non-invasive alternative.status: publishe

NLO QCD+EW predictions for HV and HV +jet production including parton-shower effects

We present the first NLO QCD+EW predictions for Higgs boson production in association with a ℓνℓ or ℓ+ℓ− pair plus zero or one jets at the LHC. Fixed-order NLO QCD+EW calculations are combined with a QCD+QED parton shower using the recently developed resonance-aware method in the POWHEG framework. Moreover, applying the improved MiNLO technique to Hℓνℓ +jet and Hℓ+ℓ− +jet production at NLO QCD+EW, we obtain predictions that are NLO accurate for observables with both zero or one resolved jet. This approach permits also to capture higher-order effects associated with the interplay of EW corrections and QCD radiation. The behavior of EW corrections is studied for various kinematic distributions, relevant for experimental analyses of Higgsstrahlung processes at the 13 TeV LHC. Exact NLO EW corrections are complemented with approximate analytic formulae that account for the leading and next-to-leading Sudakov logarithms in the high-energy regime. In the tails of transverse-momentum distributions, relevant for analyses in the boosted Higgs regime, the Sudakov approximation works well, and NLO EW effects can largely exceed the ten percent level. Our predictions are based on the POWHEG BOX RES+OpenLoops framework in combination with the Pythia 8.1 parton shower

Strength and hypertrophy responses to constant and decreasing rest intervals in trained men using creatine supplementation

<p>Abstract</p> <p>Background</p> <p>The purpose of the current study was to compare strength and hypertrophy responses to resistance training programs that instituted constant rest intervals (CI) and decreasing rest intervals (DI) between sets over the course of eight weeks by trained men who supplemented with creatine monohydrate (CR).</p> <p>Methods</p> <p>Twenty-two recreationally trained men were randomly assigned to a CI group (n = 11; 22.3 ± 1 years; 77.7 ± 5.4 kg; 180 ± 2.2 cm) or a DI group (n = 11; 22 ± 2.5 years; 75.8 ± 4.9 kg; 178.8 ± 3.4 cm). Subjects in both groups supplemented with CR; the only difference between groups was the rest interval instituted between sets; the CI group used 2 minutes rest intervals between sets and exercises for the entire 8-weeks of training, while the DI group started with a 2 minute rest interval the first two weeks; after which the rest interval between sets was decreased 15 seconds per week (i.e. 2 minutes decreasing to 30 seconds between sets). Pre- and post-intervention maximal strength for the free weight back squat and bench press exercises and isokinetic peak torque were assessed for the knee extensors and flexors. Additionally, muscle cross-sectional area (CSA) of the right thigh and upper arm was measured using magnetic resonance imaging.</p> <p>Results</p> <p>Both groups demonstrated significant increases in back squat and bench press maximal strength, knee extensor and flexor isokinetic peak torque, and upper arm and right thigh CSA from pre- to post-training (p ≤ 0.0001); however, there were no significant differences between groups for any of these variables. The total volume for the bench press and back squat were significantly greater for CI group versus the DI group.</p> <p>Conclusions</p> <p>We report that the combination of CR supplementation and resistance training can increase muscular strength, isokinetic peak torque, and muscle CSA, irrespective of the rest interval length between sets. Because the volume of training was greater for the CI group versus the DI group, yet strength gains were similar, the creatine supplementation appeared to bolster adaptations for the DI group, even in the presence of significantly less volume. However, further research is needed with the inclusion of a control group not receiving supplementation combined and resistance training with decreasing rest intervals to further elucidate such hypotheses.</p

Universality of next-to-leading power threshold effects for colourless final states in hadronic collisions

SCOAP

Practical nutritional recovery strategies for elite soccer players when limited time separates repeated matches

Specific guidelines that aim to facilitate the recovery of soccer players from the demands of training and a congested fixture schedule are lacking; especially in relation to evidence-based nutritional recommendations. The importance of repeated high level performance and injury avoidance while addressing the challenges of fixture scheduling, travel to away venues, and training commitments requires a strategic and practically feasible method of implementing specific nutritional strategies. Here we present evidence-based guidelines regarding nutritional recovery strategies within the context of soccer. An emphasis is placed on providing practically applicable guidelines for facilitation of recovery when multiple matches are played within a short period of time (i.e. 48 h). Following match-play, the restoration of liver and muscle glycogen stores (via consumption of ~1.2 gkg-1h-1 of carbohydrate) and augmentation of protein synthesis (via ~40 g of protein) should be prioritised in the first 20 minutes of recovery. Daily intakes of 6-10 gkg-1 body mass of carbohydrate are recommended when limited time separates repeated matches while daily protein intakes of >1.5 gkg-1 body mass should be targeted; possibly in the form of multiple smaller feedings (e.g., 6 x 20-40 g). At least 150% of the body mass lost during exercise should be consumed within 1 h and electrolytes added such that fluid losses are ameliorated. Strategic use of protein, leucine, creatine, polyphenols and omega-3 supplements could also offer practical means of enhancing post-match recovery. Keywords: soccer, nutrition, recovery, polyphenols, omega-3, creatine, fixture, congestio