The effects of theaflavin-enriched black tea extract on muscle soreness, oxidative stress, inflammation, and endocrine responses to acute anaerobic interval training: a randomized, double-blind, crossover study

<p>Abstract</p> <p>Background</p> <p>Muscle soreness and decreased performance often follow a bout of high-intensity exercise. By reducing these effects, an athlete can train more frequently and increase long-term performance. The purpose of this study is to examine whether a high-potency, black tea extract (BTE) alters the delayed onset muscle soreness (DOMS), oxidative stress, inflammation, and cortisol (CORT) responses to high-intensity anaerobic exercise.</p> <p>Methods</p> <p>College-age males (N = 18) with 1+ yrs of weight training experience completed a double-blind, placebo-controlled, crossover study. Subjects consumed the BTE (1,760 mg BTE·d^-1) or placebo (PLA) for 9 days. Each subject completed two testing sessions (T1 & T2), which occurred on day 7 of the intervention. T1 & T2 consisted of a 30 s Wingate Test plus eight 10 s intervals. Blood samples were obtained before, 0, 30 & 60 min following the interval sessions and were used to analyze the total to oxidized glutathione ratio (GSH:GSSG), 8-isoprostane (8-iso), CORT, and interleukin 6 (IL-6) secretion. DOMS was recorded at 24 & 48 h post-test using a visual analog scale while BTE or PLA continued to be administered. Significance was set at <it>P < 0.05</it>.</p> <p>Results</p> <p>Compared to PLA, BTE produced significantly higher average peak power (<it>P = 0.013</it>) and higher average mean power (<it>P = 0.067</it>) across nine WAnT intervals. BTE produced significantly lower DOMS compared to PLA at 24 h post test (<it>P < 0.001</it>) and 48 h post test (<it>P < 0.001</it>). Compared to PLA, BTE had a slightly higher GSH:GSSG ratio at baseline which became significantly higher at 30 and 60 min post test (<it>P < 0.002</it>). AUC analysis revealed BTE to elicit significantly lower GSSG secretion (<it>P = 0.009</it>), significantly higher GSH:GSSG ratio (<it>P = 0.001</it>), and lower CORT secretion (<it>P = 0.078</it>) than PLA. AUC analysis did not reveal a significant difference in total IL-6 response (<it>P = 0.145</it>) between conditions.</p> <p>Conclusions</p> <p>Consumption of theaflavin-enriched black tea extract led to improved recovery and a reduction in oxidative stress and DOMS responses to acute anaerobic intervals. An improved rate of recovery can benefit all individuals engaging in high intensity, anaerobic exercise as it facilitates increased frequency of exercise.</p

Genetic variation and exercise-induced muscle damage: implications for athletic performance, injury and ageing.

Prolonged unaccustomed exercise involving muscle lengthening (eccentric) actions can result in ultrastructural muscle disruption, impaired excitation-contraction coupling, inflammation and muscle protein degradation. This process is associated with delayed onset muscle soreness and is referred to as exercise-induced muscle damage. Although a certain amount of muscle damage may be necessary for adaptation to occur, excessive damage or inadequate recovery from exercise-induced muscle damage can increase injury risk, particularly in older individuals, who experience more damage and require longer to recover from muscle damaging exercise than younger adults. Furthermore, it is apparent that inter-individual variation exists in the response to exercise-induced muscle damage, and there is evidence that genetic variability may play a key role. Although this area of research is in its infancy, certain gene variations, or polymorphisms have been associated with exercise-induced muscle damage (i.e. individuals with certain genotypes experience greater muscle damage, and require longer recovery, following strenuous exercise). These polymorphisms include ACTN3 (R577X, rs1815739), TNF (-308 G>A, rs1800629), IL6 (-174 G>C, rs1800795), and IGF2 (ApaI, 17200 G>A, rs680). Knowing how someone is likely to respond to a particular type of exercise could help coaches/practitioners individualise the exercise training of their athletes/patients, thus maximising recovery and adaptation, while reducing overload-associated injury risk. The purpose of this review is to provide a critical analysis of the literature concerning gene polymorphisms associated with exercise-induced muscle damage, both in young and older individuals, and to highlight the potential mechanisms underpinning these associations, thus providing a better understanding of exercise-induced muscle damage

Game feature and expertise effects on experienced richness, control and engagement in game play

The extent to which game play is experienced as engaging is an important criterion for the playability of video games. This study investigates how video games can be designed towards increased levels of experienced engagement over time. For this purpose, two experiments were conducted in which a total of 35 participants repeatedly played a video game. Results indicate that experienced engagement is based on the extent to which the game provides rich experiences as well as by the extent to which the game provides a sense of control. In view of the influence of both game features and players’ expertise on the levels of experienced richness and control, it is concluded that game features should be modified over time to maintain optimal levels of engagement

Investigation of Genetic Variation Underlying Central Obesity amongst South Asians

The LOLIPOP study is supported by the National Institute for Health Research (NIHR) Comprehensive Biomedical Research Centre Imperial College Healthcare NHS Trust, the British Heart Foundation (SP/04/002), the Medical Research Council (G0601966,G0700931), the Wellcome Trust (084723/Z/08/Z), and the NIHR (RP-PG-0407-10371). The work was carried out in part at the NIHR/Wellcome Trust Imperial Clinical Research Facility. The Sikh Diabetes Study is supported by National Institute of Health grants KO1TW006087, funded by the Fogarty International Center, R01DK082766, funded by National Institute of Diabetes and Digestive and Kidney Diseases, and a seed grant from University of Oklahoma Health Sciences Center, Oklahoma City, USA. The Mauritius Family Study is supported by the Mauritius Ministry of Health and Quality of Life, Australian Government National Health and Medical Research Council NHMRC project grant numbers 1020285 and 1037916, the Victorian Government’s OIS Program, and partly funded by US National Institutes of Health Grant DK-25446. We thank the participants and research staff who made the study possible.South Asians are 1/4 of the world’s population and have increased susceptibility to central obesity and related cardiometabolic disease. Knowledge of genetic variants affecting risk of central obesity is largely based on genome-wide association studies of common SNPs in Europeans. To evaluate the contribution of DNA sequence variation to the higher levels of central obesity (defined as waist hip ratio adjusted for body mass index, WHR) among South Asians compared to Europeans we carried out: i) a genome-wide association analysis of >6M genetic variants in 10,318 South Asians with focused analysis of population-specific SNPs; ii) an exome-wide association analysis of ~250K SNPs in protein-coding regions in 2,637 South Asians; iii) a comparison of risk allele frequencies and effect sizes of 48 known WHR SNPs in 12,240 South Asians compared to Europeans. In genome-wide analyses, we found no novel associations between common genetic variants and WHR in South Asians at P<5x10-8; variants showing equivocal association with WHR (P<1x10-5) did not replicate at P<0.05 in an independent cohort of South Asians (N = 1,922) or in published, predominantly European meta-analysis data. In the targeted analyses of 122,391 population-specific SNPs we also found no associations with WHR in South Asians at P<0.05 after multiple testing correction. Exome-wide analyses showed no new associations between genetic variants and WHR in South Asians, either individually at P<1.5x10-6 or grouped by gene locus at P<2.5x10−6. At known WHR loci, risk allele frequencies were not higher in South Asians compared to Europeans (P = 0.77), while effect sizes were unexpectedly smaller in South Asians than Europeans (P<5.0x10-8). Our findings argue against an important contribution for population-specific or cosmopolitan genetic variants underlying the increased risk of central obesity in South Asians compared to Europeans.Yeshttp://www.plosone.org/static/editorial#pee

RELATIONSHIP BETWEEN FRONTAL PLANE KINEMATICS DURING THE SINGLE-LEG SQUAT: A PILOT STUDY

Havana O. Charles1, JP Barfield2, FACSM. 1Lander University, Greenwood, SC. 2UNC Charlotte, Charlotte, NC. Background: Identifying the relationships between various frontal plane kinematics during a multi-segmental motion assessment may help clinicians determine the best path of treatment. Specifically, the single-leg squat is a low-cost kinetic chain assessment that has been determined to be clinically useful. Purpose: The purpose of this project was to determine the relationship between various frontal plane kinematics during the single-leg squat amongst a group of collegiate softball players. Methods: Eight female softball athletes (age, 20.85 ± 2.05 years; height, 167.8 ± 4.7 cm; weight, 74.3 ± 7.8 kg) agreed to participate and performed three single-leg squats with their non-dominant leg on a force plate. Center of pressure excursion was collected in the mediolateral direction. Peak values for knee valgus, hip adduction, lateral pelvic tilt, and lateral trunk tilt were obtained between 45° of knee flexion during the descent and 45° of knee flexion during the ascent using an electromagnetic tracking system. Data for all three trials were averaged and analyzed with JASP 0.10.2. Results: Pearson product moment correlations revealed a strong relationship between mediolateral center of pressure excursion and knee varus/valgus (r[8]=0.91, p\u3c0.01). Greater mediolateral center of pressure excursion was strongly related to increased knee valgus. Additionally, a strong relationship between lateral pelvic tilt and hip adduction (r[8]=-0.79, p=0.02) was observed. Greater lateral pelvic tilt was strongly related to increased contralateral hip adduction. Conclusion: The results partially confirmed our hypothesis that strong relationships exist between various frontal plane kinematics during the single leg squat. Increased center of pressure excursion and knee valgus have been used as clinical measures of lower extremity instability. When observing knee valgus in dynamic assessments, awareness of the strong link with base of support instability may help treatment decisions. Additionally, pelvic lateral tilt is another clinical measure of stability. The relationship between lateral pelvic tilt and contralateral hip adduction implies that frontal plane hip motion during a single-leg squat is due to muscular weakness around the lumbopelvic hip complex. Further research should examine muscle activity during the single-leg squat to further understand the observed break between knee valgus and hip adduction

EVIDENCE-BASED CLASSIFICATION: VALID MEASURES OF IMPAIRMENT IN POWER SOCCER

JP Barfield, FACSM1, Kirsten Clancy2, Allison Foster2, Hannah Millsaps2, Samuel T. Rutherford2, Sarah Whitsett2, Stephanie Williams3. 1UNC Charlotte, Charlotte, NC. 2Emory & Henry College, Marion, VA. 3Emory & Henry College, Emory, VA. BACKGROUND: The International Paralympic Committee (IPC) encourages participation in sport by ensuring athletes with varied impairments are selected and grouped appropriately to minimize the effect of impairment on sport outcomes. To accomplish this goal, all sport governing bodies within the IPC must have a classification system that is evidence-based to determine an athlete’s eligibility and grouping for sport competition. The purpose of this study was to identify and examine the measurement properties of prospective classification assessments for the sport of Power Soccer. METHODS: Thirty-six power soccer athletes (MAge = 25±15 yrs, MExpericne = 7±7 yrs) with severe physical impairments (i.e., cerebral palsy, muscular dystrophy, spinal cord injury, spinal muscular atrophy) completed multiple tests of impairment and performance selected from previously identified domains. IRB and informed consent were obtained prior to the study. RESULTS: Acceptable inter-rater reliability (via ICC) was demonstrated on multiple tests of impairment, including functional dexterity (1.0), opposite pinch (0.78), lateral pinch (0.87), cervical range of motion (0.92), cervical extension force (0.84), lateral force (0.89), and total force (0.89). Performance tests (reverse slalom, spider, Figure 8) also demonstrated acceptable inter-rater reliability (0.97 to 0.99) with good test-retest reliability for some items (reverse slalom, Figure 8, total time). DISCUSSION: Test items selected from previously identified domains (determinants) were a good first step to meet the IPC recommendations of developing/identifying valid, objective, ratio-scaled measures of impairment and performance. These data support Step 3 (of 5) in the IPC process of developing an evidence-based classification system for the sport of power soccer, a game designed for individuals with impairment severity that mandates the use of a power wheelchair (or electric wheelchair) for sport

Physical, Sensory, and Intellectual Impairments.

Exercise testing and exercise prescription in individuals with different I) motor impairments determined by several health conditions (e.g., spinal cord injury, amputation, cerebral palsy, ecc.), II) sensory impairments and III) intellectual impairments