Effect of football activity and physical fitness on information processing, inhibitory control and working memory in adolescents

Background Whilst an acute bout of exercise has been shown to enhance subsequent cognition, including in adolescents, the effects of team games (of which Football is the most popular) has received little attention. Therefore, this study examined: the effect of an acute bout of outdoor Football activity on information processing, inhibitory control, working memory and circulating brain-derived neurotrophic factor (BDNF) in adolescents; the effect of physical fitness on cognition and; the moderating effect of physical fitness on the acute exercise responses. Methods Following familiarisation, 36 adolescents (16 girls) took part in two trials (60-min Football and 60-min seated rest) separated by 7-d in a counterbalanced, crossover design. Information processing and inhibitory control (Stroop Test), and working memory (Sternberg Paradigm) were assessed 30-min before exercise/rest and immediately, 45- and 90-min post-exercise/rest. Capillary blood samples were obtained before exercise/rest and up to 120-min post-exercise/rest. The median split of distance covered on the MSFT was used to divide the group into high- and low-fit groups. Results Performance on the cognitive function tasks was similar between Football and seated rest (trial*time interactions; all p > .05). However, the high-fit group had overall quicker response times on both levels of the Stroop Task and all three levels of the Sternberg Paradigm (main effect of fitness; all p < .001). Furthermore, the exercise-cognition relationship was moderated by physical fitness, with improvements in working memory response times seen post-exercise, only in the high-fit group (trial*time*fitness interaction, p < .05). Circulating BDNF was unaffected by the Football activity and physical fitness (p > .05). Conclusion The present study shows that higher levels of physical fitness are beneficial for cognitive function and provides novel evidence that an ecologically valid, and popular, form of exercise is beneficial for working memory following exercise, in high-fit participants only.

Effects of Preferred and Nonpreferred Warm-Up Music on Exercise Performance

This study investigated the effects of preferred and non-preferred warm-up music listening conditions on subsequent exercise performance. A total of 12 physically active male and female participants engaged in a crossover, counterbalanced research design in which they completed exercise trials after 3 different warm-up experiences of (a) no music (NM), (b) preferred music (PREF), and (c) nonpreferred music (NON-PREF). Participants began warming up by rowing at 50% of of age-predicted heart rate maximum (HRmax) for 5 minutes while exposed to the three music conditions. Immediately following the warm-up and cessation of any music, participants completed a 2000-m rowing time trial as fast as possible. Relative power output, trial time, heart rate, rating of perceived exertion, and motivation were analyzed. Results indicated that, compared with NM, relative power output was significantly higher ( p = .018), trial time was significantly lower ( p = .044), and heart rate was significantly higher ( p = .032) during the PREF but not the NON-PREF condition. Rating of perceived exertion was not altered, regardless of music condition ( p > .05). Motivation to exercise was higher during the PREF condition versus the NM ( p = .001) and NON-PREF ( p < .001) conditions. Listening to preferred warm-up music improved subsequent exercise performance compared with no music, while nonpreferred music did not impart ergogenic benefit.

IMPLEMENTATION OF GOVERNMENT PROCUREMENT OF GOODS / SERVICES LAW AS A STATE ADMINISTRATIVE DISPUTE

Goods/Services Procurement is one kind classifications of state administrative disputes whose resolutions are often incomplete, and even do not provide benefits for those who submit them. It's affected by long trial time compared to the short duration of the procurement process and the implementation of government projects, as well as a different paradigm of Administrative Judges addressing the context of Goods/ Services Procurement as a rule of public law or private law. Synchronizing the paradigms about the legal context in the procurement of goods/services among the Administrative Judges, are vital for the benefit and certainty of law in the settlement of administrative disputes over goods/services procurement.

Fluid Restriction Decreases Solid Food Consumption Post-Exercise

Dehydration in rodents induces anorexia. In humans however, the role of dehydration in energy intake is controversial. This study investigated the effect of extreme fluid restriction on acute energy intake during and after exercise-induced dehydration. Eight physically active participants performed two exercise sessions to induce dehydration. After the exercise, the men were allowed to either rehydrate for 2 h or were maintained in a hypohydrated state, in a randomized manner. After 2 h, they were given cereal bars ad libitum for 1 h. Blood and saliva samples of the participants were collected before the exercise session, after the exercise session, after rehydration, and after the meal. Post-exercise energy intake differed between hypohydrated (1430 ± 210 kcal) and rehydrated (2190 ± 780 kcal) trials (p = 0.01). For the concentrations of ghrelin and leptin, there were no significant effects of time (p = 0.94, p = 0.21), between trials (p = 0.09, p = 0.99), or due to a trial–time interaction (p = 0.64, p = 0.68), respectively. The concentrations of peptide YY (PYY) were not different between trials (p = 0.94) but there was a significant effect of time (p = 0.0001) and a trial–time interaction (p = 0.01), with higher levels in the rehydration trial after eating in response to a higher energy intake. For saliva production, there was a significant effect of time (p = 0.02) and a trial–time interaction (p = 0.04), but no between-trial effect (p = 0.08). In conclusion, extreme fluid restriction decreased acute food intake after exercise, which may be explained by a lower flow of saliva.

Assessment of vibration exposure and physiological responses of crew members during Infantry Combat Vehicle (ICV) operation: a pilot study

BackgroundOperation of infantry combat vehicle (ICV) influences the cardiorespiratory responses as well as the risk of vibration exposure on the crew members which adversely affect their performance and health.AimTo assess the effect of stress factors, that is, ICV’s compartmental temperature, relative humidity (RH) and vehicular vibration on the physiological parameters (heart rate (HR), respiratory frequency (RF), estimated core body temperature (ECT)) of the crew members during the ICV operation.MethodsA 1 hour run trial of the ICV operation was conducted with its crew members at their respective positions. Compartmental temperature and RH were monitored at an interval of every 15 min during the run trial. Physiological parameters were monitored continuously during the run trial. Whole body vibration (WBV) and hand-arm vibration (HAV) of the crew members were also measured during the run trial time.ResultsThe findings showed a strong positive correlation (p<0.05) between the increasing compartmental temperature and RH with its run trial time. Significant changes were observed in the physiological parameters (p<0.05) along with the increasing run trial time. Additionally, the physiological parameters showed a strong positive correlation with compartmental temperature and RH, respectively (p<0.05). Also, a significant increase (p<0.05) in the muscle strength was recorded after their exposure to ICV operation. The study also confirmed high level of WBV exposure of the crew members during the ICV operation.ConclusionIncrease in HR, RF and ECT along with increase in temperature and RH is a predictive indicator of physiological stress. Moreover, high levels of vibration exposure of various operations may bring deleterious effect on soldiers’ health as well as their performance. Proper ergonomic intervention can reduce exposure to vibration, physiological stress and increase comfort which may ultimately ensure an optimum performance of soldiers and successful completion of mission.

The WISDOM Personalized Breast Cancer Screening Trial: Simulation Study to Assess Potential Bias and Analytic Approaches

Background WISDOM (Women Informed to Screen Depending on Measures of Risk) is a randomized trial to assess whether personalized breast cancer screening—where women are screened biannually, annually, biennially, or not at all depending on risk and age—can prevent as many advanced (stage IIB or higher) cancers as annual screening in women ages 40–74 years across 5 years of trial time. The short study time in combination with design choices of not requiring study entry and exit mammograms for all participants may introduce different sources of bias in favor of either the personalized or the annual arm. Methods We designed a simulation model and performed 5000 virtual WISDOM trials to assess potential biases. Each virtual trial simulated 65 000 randomly assigned participants who were each assigned a risk stratum and a time to stage of at least IIB cancer sampled from an exponential distribution with the hazard rate based on the risk stratum. Results from the virtual trials were used to evaluate two candidate analysis strategies with respect to susceptibility for introducing bias: 1) difference between arms in total number of events over total trial time, and 2) difference in number of events within complete screening cycles. Results Based on the simulations, about 86 stage IIB or higher cancers will be detected within the trial and the total exposure time will be about 74 000 years in each arm. Potential ascertainment bias is introduced at study entry and exit. Analysis strategy 1 works better for the nonscreened stratum, whereas method 2 is considerably more unbiased for the strata of women screened biennially or every 6 months. Conclusion Combining the two candidate analysis approaches gives a reasonably unbiased analysis based on the simulations and is the method we will use for the primary analysis in WISDOM. Publishing the WISDOM analysis approach provides transparency and can aid the design and analysis of other individualized screening trials.

Gut-training: the impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance

Due to gastrointestinal tract adaptability, the study aimed to determine the impact of gut-training protocol over 2 weeks on gastrointestinal status, blood glucose availability, fuel kinetics, and running performance. Endurance runners (n = 25) performed a gut-challenge trial (GC1), consisting of 2 h running exercise at 60% V̇O2maxwhilst consuming gel-discs containing 30 g carbohydrates (2:1 glucose/fructose, 10% w/v) every 20 min and a 1 h distance test. Participants were then randomly assigned to a carbohydrate gel-disc (CHO-S), carbohydrate food (CHO-F), or placebo (PLA) gut-training group for 2 weeks of repetitive gut-challenge intervention. Participants then repeated a second gut-challenge trial (GC2). Gastrointestinal symptoms reduced in GC2 on CHO-S (60%; p = 0.008) and CHO-F (63%; p = 0.046); reductions were greater than PLA (p < 0.05). H2peak was lower in GC2 on CHO-S (mean (CI): 6 (4–8) ppm) compared with CHO-F (9 (6–12) ppm) and PLA (12 (2–21) ppm) (trial × time: p < 0.001). Blood glucose concentration was higher in GC2 on CHO-S (7.2 (6.3–8.1) mmol·L−1) compared with CHO-F (6.1 (5.7–6.5) mmol·L−1) and PLA (6.2 (4.9–7.5) mmol·L−1) (trial × time: p = 0.015). No difference in oxidation rates, plasma I-FABP, and cortisol concentrations were observed between groups and trials. Distance test improved on CHO-S (5.2%) and CHO-F (4.3%) in GC2, but not on PLA (–2.1%) (trial × time: p = 0.009). Two weeks of gut-training with CHO-S and CHO-F improved gastrointestinal symptoms and running performance compared with PLA. CHO-S also reduced malabsorption and increased blood glucose availability during endurance running compared with PLA.