The complex role of physical exercise and reactive oxygen species on brain

Reactive oxygen species （ROS） are continuously generated during aerobic metabolism and at moderate level. They play a role in redox signaling, but in significant concentration they cause oxidative damage and neurodegeneration. Because of the enhanced sensitivity of brain to ROS, it is especially important to maintain the normal redox state in different types of neuron cells. In last decade it became clear that regular exercise beneficially affects brain function, and can play an important preventive and therapeutic role in stroke, Alzheimer, and Parkinson diseases. The effects of exercise appear to be very complex and could include neurogenesis via neurotrophic factors, increased capillariszation, decreased oxidative damage, and increased proteolyfic degradation by proteasome and neprilysin. Data from our and other laboratories indicate that exercise-induced modulation of ROS levels plays a role in the protein content and expression of brain-derived neurotrophic factor, tyrosinerelated kinase B （TrkB）, and cAMP response element binding protein, resulting in better function and increased neurogenesis. Therefore, it appears that exercise-induced modulation of the redox state is an important means, by which exercise benefits brain function, increases the resistance against oxidative stress, facilitates recovery from oxidative stress, and attenuates age-associated decline in cognition.

Performance Model Analysis of Armenian Premier League Soccer Players Using Global Positioning System Technology and Comparison between European Championship

The aim of this research was to analyze the PPM of Armenian Premier League using 25 GPS 10 Hz(K-Sport,Montelabbate,Italy),in order to compare data from literature from major European championship.In total 25 matches were analyzed from one team militant in Armenian Premier League(10 wins,10 loses and 5 draws),33 different players(age 24.3±4.2,height 1.76±4.2 and weight 74±3.5)and in total 270 performances(10.8 for matches).Matches were divided in First Half(T1),Second Half(T2),Second Half Substitution(T2 Sub),Full Match,Full Match Substitution(Full Match Sub)and Total Match(Total)that include all the players detected during a games.Furthermore,all matches were divided even by quarters 0-15,15-30,30-45,45-60,60-75 and 75-90,only players that played all match were included in this analyses,in order to check the performance decreasing during the time.All data were added in an Excel Spreadsheet in order to build a database,to organize and better analyze data,cataloging events for data,results,and role of players.Average data from Armenian Premier League in comparison with literature data from European and Italian Championship show that in every parameter,the Armenian Premier League is under the average.This is obviously related to the non-high level of the Armenian football that is in fact placed at the 106°place of the FIFA ranking(update 7 June 2019).Physical data represent an indicator of performance but also of the qualitative level of the league and of individual players.For this reason,the use of the match analysis can be decisive to verify the PPM,in order to better evaluate the championships,teams,and players,in order to build an easier search and discovery of talents.

Difference in Surface Roughness of Ethylene-Vinyl-Acetate Sheet before and after Application of Finishing Liquid: Part 2 Changes over Time in Surface Roughness

Surface texture of the mouthguard affects the sense of adaptation in the athlete and further affects hygiene. The aim of this study was to investigate the changes over time in surface roughness after finish polishing of ethylene vinyl acetate (EVA) sheets and before and after finishing liquid application, and to evaluate its effectiveness. Total of 160 specimens of EVA (3 × 3 mm) were divided into 4 groups according to polishing condition (control = unpolished;RB = Robinson-brush;LF = Lisko-Fine, and MW = Mouthguard-wheel). Polishing was performed at low speed by using a straight headpiece. The rotation speed was 5000, 4000 and 6000 rpm for RB, LF, and MW, respectively. Next, a finishing liquid was applied to each specimen. Changes over time in surface roughness before and after application of the finishing liquid were compared by a non-contact surface shape measuring machine. The arithmetic average height (Sa) was measured. The measurement time points were before application, immediately after application, and at 5, 10, and 15 min after application. The changes over time of the surface roughness of the sheet before and after application of the finishing liquid were analyzed by two-way analysis of variance and Bonferroni’s multiple comparison tests. Surface roughness of the specimen before application became coarse in the order of control;MW, LF and RB, and Sa were about 0.21 μm, 2.03 μm, 2.94 μm, and 4.72 μm, respectively. That showed the same order after finishing liquid application. Significant decrease in Sa for RB and LF were seen at 10 min after application and at 5 min after application, respectively. Sa of MW was not significantly different before and after application. The results of this study showed that a lubricity of about 1.0 μm increases within 5 - 10 min of application of finishing liquid, but in cases where polishing was performed to about 2.0 μm;the application of finishing liquid has no ef-fect.

Overhead shoulder press - In-front of the head or behind the head？

Background： Using a cross-sectional design comparison, two overhead press techniques （in-front of the head or behind the head） were compared. The purpose of this study was to determine the impact of behind the head or in-front of the head overhead pressing technique on shoulder range of movement （ROM） and spine posture. The overhead press is commonly prescribed exercise. The two techniques （in-front of the head or behind the head） may influence joint mechanics and therefore require an objective analysis. Methods： Passive shoulder ROM quantified using goniometric measures, dynamic ROM utilised three-dimensional （3D） biomechanical mea- sures （120 Hz） of 33 participants performing overhead pressing in a seated position. The timing and synchronisation of the upper limb shoulder and spine segments were quantified and influence of each technique was investigated. Results： The in-front technique commenced in lordotic position, whilst behind the head technique commenced in kyphotic position. Behind the head technique started with less thoracic extension than in-front condition. The thoracic spine remained extended and moved between 12~ and 15~ regardless of gender or technique. The techniques resulted in a significant difference between genders. Males were able to maintain a flat or normal lumbar lordosis, whereas females tended to kyphotic. Conclusion： Shoulder ROM was within passive ROM for all measures except external rotation for males with the behind the head technique. To avoid possible injury passive ROM should be increased prior to behind the head protocol. Females showed greater spine movements, suggesting trunk strengthening may assist overhead pressing techniques. For participants with normal trunk stability and ideal shoulder ROM, overhead pressing is a safe exercise （for the shoulder and spine） when performed either in-front of or behind the head.

Daily heart rate variability of Paralympic gold medallist swimmers： A 17-week investigation

Objectives： Heart rate variability （HRV） can be a simple, non-invasive method of gauging cardiac autonomic nervous system fluctuations across periodised training workloads and taper in elite athlete populations. The purpose of these three case studies was to examine daily cardiac autonomic variations in Paralympic athletes leading in to the Paralympic games. Methods： Three Paralympie gold medallist swimmers were monitored daily for their resting HRV over a 17-week monitoring period leading up to the Paralympic games. Specific time- and frequency-domain measures, along with non-linear indices of HRV were calculated for all analyses. All HRV data were analysed individually using daily values, weekly average values, and average values for rest and training phases. Results： A significant difference in HRV was seen for all variables between athlete 1 and athletes 2 and 3 （amputee disabilities） during the entire monitoring period. Conclusion： Despite minimal long-term changes, both swimming classification and disability type significantly influence HRV during athlete monitoring. An increased understanding of individual responses to training, travel, and other outside influences affecting Paralympic athletes could potentially lead to improved management and monitoring of training workloads for enhanced nerformance.

Session RPE and Speed High Intensity Distance in Meters(D_SHI mt):A Valid Method to Analyze Training Load in Soccer Players

The purpose of this study is to verify the physiological effect and describe the intensity of training in response to internal and external loads,through Session Rate of Perceived Exertion and Speed High Intensity Distance in Meters reports,on professional soccer players engaged in weekly training(199 Sessions,43 weeks)and league games(32 official matches).Twenty-two male professional soccer players(n=22)of the Italian national championship under-19 are involved in this study during the season 2014-2015.Daily,Weekly and Monthly RPE(perceived exertion)Session(Borg CR-10 Scale)is a good indicator of the amount of work done:training time multiplied by perceived effort(TL=Training Time×RPE).With Arbitrary units(a.u.)produced by the individual and used for team-based data analysis,we analyze the intensity produced by workout depending on the working time.Furthermore,by means of global positioning system technology(K-Sport,Montelabbate PU,Italy 10 Hz),we statistically established the existing relationship with high intensity speed distance(>16 km/h)and session rate of perceived exertion to describe how the internal(represented by the sum of the stresses that the body undergoes an external load;is strictly subjective)and external loads(the objective quantification of the means used in training km routes,running speed,slope,type of recovery),are correlated(r=0.87,p<0.01,95%CI).The statistical analysis highlights how these methods are suitable to quantifying the high-intensity work done by the soccer player during the workout and the game.

Physiological Responses to Agonist-Antagonist Superset Resistance Training

Purpose To investigate the physiological responses to low-load,superset resistance training(two exercises for the agonist and antagonist muscles performed without rest between exercises)to failure using elastic bands.Methods Twenty-three athletes were randomized to either a superset group(S,n=12,average age:19.8±1.5 years)or a traditional set group(T,n=11,average age:20.1±1.4 years).Strength,cross-sectional area(CSA)and muscular endurance of the biceps and triceps brachii were assessed before and after 8 weeks.Acute responses(muscle thickness)were measured during one testing session.Results Muscle thickness of the biceps significantly increased in both T group(P<0.05)and S group(P<0.05)after a single bout of Training.The triceps did not show significant increases in either T group(P>0.05)or S group(P>0.05).Blood lactate also increased in both groups after one bout of training(T:from 1.3±0.3 to 5.5±2.4 mmol/L,S:from 1.4±0.5 to 5.1±1.5 mmol/L,P<0.05).After 8-week training,both groups showed significant increases in the biceps(T:13.2%±5.0%;S:12.9%±7.3%,P<0.05)and triceps(T:9.5%±9.3%,S:4.8%±4.1%,P<0.05)without differences between groups.Increases in one repetition maximum for the bench press(7.8%±6.5%,P<0.05)and maximal voluntary contraction for the arm extensors(9.3%±11.6%,P<0.05)were observed for the T group only.Increases in muscular endurance were observed only in the S group for the bench press(26.0%±19.1%,P<0.05)and the barbell curl(17.2%±16.6%,P<0.05).Conclusions Superset training may enhance muscular endurance while attenuating maximal strength gains.There does not appear to be a hypertrophic benefit to performing superset training,but it may provide a time-efficient strategy to achieve adaptations in muscle mass.