Acute Responses of Youth Elite Players to a Football Match in Terms of Blood Markers.

The current study verified the acute responses of participants to a football match in terms of blood markers. Sixteen elite U-18 male football players were divided into two groups: experimental (EG, n = 10), who played a friendly football match; and control (CG), who were not exposed to any physical exertion. Intravenous blood samples were collected from both groups at baseline, pre-match, half-time, and post-match. The blood analysis consisted of four groups: immunological (leukocytes, platelets, and cortisol), muscle damage (creatine kinase and lactate dehydrogenase), metabolic (lactate, glucose, erythrocytes, hematocrit, hemoglobin, and urea), and electrolytic (sodium, calcium, and potassium). Edwards' training impulse demonstrated that the first half was more demanding than the second half (p = 0.020). Significant changes between time points and groups were observed for leukocytes (pre-match: 6920 ± 1949; post-match: 13,890 ± 3292; p ≤ 0.05) and cortisol (pre-match: 10.78 ± 3.63; post-match: 19.15 ± 7.40; p ≤ 0.05). CK (pre-match: 516.50 ± 248.38; post-match: 713.70 ± 308.20; p ≤ 0.05) and LDH (pre-match: 348.80 ± 36.49; post-match: 414.80 ± 26.55; p ≤ 0.05) increased significantly across the time points for the EG, with no difference between the groups, however. Raised lactate (pre-match: 1.05 ± 0.32; post-match: 3.24 ± 1.60; p ≤ 0.05) and glucose (pre-match: 72.54 ± 9.76; post-match: 101.42 ± 19.87; p ≤ 0.05) differences between the groups at half-time were also observed. These current findings provide helpful information to better understand football match demands regarding physiological effects.

Relationship Between Body Size and Skeletal Age with Muscle Damage in Young Soccer Players.

This study verified the relationship between body size and skeletal age (SA) with the behavior of blood markers of muscle damage and delayed onset muscle soreness (DOMS) after a soccer match in the U-13 and U-15 categories. The sample consisted of 28 soccer players in the U-13 and 16 in the U-15 categories. Creatine kinase (CK), lactate dehydrogenase (LDH), and DOMS were evaluated up to 72 h after the match. Muscle damage was elevated at 0 h in U-13, and from 0 h to 24 h in U-15. DOMS increased from 0 h to 72 h in U-13 and from 0 h to 48 h in U-15. Significant associations of SA and fat-free mass (FFM) with muscle damage markers and DOMS were observed only in U-13, specifically at time 0 h, when SA explained 56% of CK and 48% of DOMS and FFM explained 48% of DOMS. We concluded that in the U-13 category, higher SA is significantly associated with muscle damage markers, and increase in FFM is associated with muscle damage markers and DOMS. Furthermore, U-13 players need 24 h to recover pre-match muscle damage markers and more than 72 h to recover DOMS. In contrast, the U-15 category needs 48 h to recover muscle damage markers and 72 h to recover DOMS.

The physical exercise-induced oxidative/inflammatory response in peripheral blood mononuclear cells: Signaling cellular energetic stress situations.

Peripheral blood mononuclear cells (PBMCs) are a variety of specialized immune cells produced in the bone marrow from hematopoietic stem cells (HSCs) that work together to protect our bodies from harmful pathogens. From a metabolic point of view, these cells can serve as sentinel tissue source for distinguishing multiple types of whole-body physiological perturbations. The significant interaction of PBMCs with systemic physiology makes these cells an attractive target for several interventions such as physical exercise. Analyses of oxidative/inflammatory and metabolic markers of PBMCs obtained from unhealthy and healthy humans have been used in monitoring immune response in different exercise conditions. It is already a common consensus that regular practice of physical exercise, that is planned, structured, and repetitive, influences personal health by altering the metabolic state and the immune system. However, the role of distinct metabolic processes responsible for maintaining metabolic balance during physical exercise in PBMCs is not fully understood. Furthermore, a complete dose-response analysis between different exercise protocols and biomarkers capable of predicting physical performance needs to be better elucidated. The absence of published reviews on this topic compromises the understanding of the crosstalk between the metabolic adaptations of PBMCs and exercise-induced changes in the immune system. Given the above, this review highlights the main findings in the literature involving the responses of PBMCs in the inflammatory/oxidative stress induced by physical exercise. The present review also highlights how distinct phenotypes and functional diversity of PBMCs make these cells an accessible alternative for assessing exercise-induced metabolic adaptations.

Panax ginseng Supplementation Increases Muscle Recruitment, Attenuates Perceived Effort, and Accelerates Muscle Force Recovery After an Eccentric-Based Exercise in Athletes.

ABSTRACT: Cristina-Souza, G, Santos-Mariano, AC, Lima-Silva, AE, Costa, PL, Domingos, PR, Silva, SF, Abreu, WC, De-Oliveira, FR, and Osiecki, R. Panax Ginseng supplementation increases muscle recruitment, attenuates perceived effort, and accelerates muscle force recovery after an eccentric-based exercise in athletes. J Strength Cond Res 36(4): 991-997, 2022-The effect of Panax ginseng during and after an eccentric-based exercise is underexplored. In this study, we investigated the effect of Panax ginseng on muscle force and muscle excitation during an eccentric-based exercise and on subsequent muscle damage and delayed-onset muscle soreness (DOMS). Using a randomized, double-blind, crossover design, 10 male track and field athletes consumed Panax ginseng or placebo for 8 days. At the fifth day, they performed 4 sets until concentric failure of a half-squat exercise, with eccentric action increased by using an eccentric-inductor device attached to their knees. The rating of perceived exertion (RPE) and vastus lateralis electromyographic (EMG) activity was measured during the half-squat. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) concentrations, DOMS, and maximal isometric voluntary contractions (MIVCs) with EMG recording were measured at 24, 48, and 72 hours after the half-squat. Panax ginseng attenuated RPE and increased EMG during the sets. The MIVC remained reduced 48 hours after exercise in the placebo but returned to baseline 24 hours after exercise in the Panax ginseng, with values at 24 and 48 hours after exercise significantly higher in the Panax ginseng than in the placebo. The EMG during MIVC was higher in the Panax ginseng than in the placebo over the time points. No significant effect of Panax ginseng on LDH, CK, and DOMS was observed. These findings suggest that Panax ginseng increases muscle excitation and attenuates perceived effort during an eccentric-based exercise as well as accelerates the recovery of muscle force in well-trained athletes.

Can a genetic profile be related to performance in young talent track and field athletes? A pilot study

Abstract Aim: This study analyzed the influences of ACE and ACTN3 gene variants in sprinters, jumpers, and endurance young athletes of track and field. Methods: 36 school-level competitors of both sex (15 girls and 21 boys; aged 16.4 ± 1.2 years; training experience 4 ± 1.2 years) practitioners of different sport disciplines (i.e., sprint, jump, and endurance athletes) participated in the study. The deoxyribonucleic acid (DNA) was extracted from peripheral blood using a standard protocol. Anthropometric measurements, 30 m sprint, squat jump (SJ), and maximal oxygen uptake (VO2max) tests were measured. Results: Genotype distribution of the ACE and ACTN3 genes did not differ between groups. In ACE DD and ACTN3 RX genotypes, the SJ test was bigger in sprinters and jumpers than in the endurance runners. In contrast, when analyzing the ACE ID genotype, sprinters had higher SJ than endurance athletes. Moreover, in the ACE DD genotype, the sprinters and jumpers' athletes had lower time in 30 m tests compared to endurance runners. However, the ACE ID and ACTN3 RX genotypes was greater aerobic fitness in endurance runners than in jumpers' athletes. Conclusion: Although the genetic profile is not a unique factor for determining athletic performance, the ACE DD and ACTN3 RX genotypes seem to favor athletic performance in power and sprint versus endurance sports. Thus, this study evidenced that assessing genetic variants could be used as an auxiliary way to predict a favorable profile for the identification of young talents of track and field.

Could physical, technical, and tactical variables differentiate the top players of the 2018 FIFA World Cup?

Abstract Aim: This study aimed to analyze the difference between tactical, technical, and physical variables in selected and unselected top players of the 2018 FIFA World Cup. Methods: A sample data of 1049 soccer players were collected by the multiple-camera computerised tracking system. Subsequently, data were analyzed and divided into two groups: selected (man of the match and top 10 players of the World Cup) and unselected players (other players). Twenty-six performance variables were used to assess tactical (passing), technical (goals, assist, shots, and fouls), and physical variables (height, distance covered, distance with and without the ball, number of sprints, maximal speed, and intensities zone 1 [low] to 5 [high]). Results: The selected players had more tactical (performed and completed more long, middle, and short pass), technical (goal for, assist, shots, shots on goal, fouls committed on them), and physical variables (covered more distance and distance with the ball, more sprints, greater speed and distance in low intensity [zone 1]). However, they were shorter in height and covered less distance in moderate intensity [zones 2 and 3] when compared to unselected players (p < 0.05). Conclusion: This study suggests that the selected players have more tactical, technical, and physical variables than the unselected players. Our findings could be used as a trustworthy tool (performance variables) to characterize the top players of the World Cup.

Associated Determinants Between Evidence of Burnout, Physical Activity, and Health Behaviors of University Students.

Risk behaviors and signs of burnout are associated with substantial health losses and university dropouts. Physical activity can be an effective approach to reduce these factors. The objective of this study was to analyze aspects related to health behaviors, physical activity, and signs of burnout in university students and their association with physical activity. The probabilistic cluster sample consisted of 3,578 regularly enrolled undergraduate students from UFPR in Curitiba, based on a population sample of 24,032 university students. The students completed the MBI-SS and NCHA II instruments. Descriptive statistics were used to identify demographic indicators and characteristics of the university environment. For the proportion of subjects with respective confidence intervals (CI = 95%), contingency tables involving the chi-square test (χ2) were used. The prevalence of signs of burnout was estimated in punctual proportions accompanied by the respective confidence intervals (CI = 95%). To analyze the associations between the independent variables and signs of burnout, the Hierarchical Logistic Regression was used through an analysis adjusted by the other independent variables involved in the models (CI = 95%). Results showed that the prevalence of individuals who showed signs of burnout was 40.4%. The hierarchical multiple regression model pointed to: female sex (OR = 1.30; 1.11-1.51); age between 20-24 years (OR = 1.51; 1.25-1.83); and 25-29 years (OR = 1.69; 1.27-2.24); being single (OR = 2.67; 1.01-7.10); presenting regular/poor health perception (OR = 1.59; 1.13-2.22), belonging to Human Sciences courses (OR = 1.37; 1.14-1.64); attending 2nd or 3rd year (OR = 1.34; 1.12-1.61); poor academic performance (OR = 5.35; 4.11-6.96); mean (OR = 2.08; 1.78-2.43). We conclude that academics showed a high prevalence of health risk behaviors and correlate and diagnose emotional problems and signs of burnout. Signs of burnout were significantly associated with the practice of physical activity in its three dimensions; however, in the adjusted analysis for demographic indicators, the characteristics of the university environment, and health behaviors, physical activity was not significant for the model.

Predicting Lactate Threshold With Rate of Perceived Exertion in Young Competitive Male Swimmers.

The purpose of this study was to verify the effectiveness of the rate of perceived exertion threshold (RPET) for predicting young competitive swimmers' lactate threshold (LT) during incremental testing. We enrolled 13 male athletes (M age = 16, SD = 0.6 years) in an incremental test protocol consisting of eight repetitions of a 100-meter crawl with 2-minute intervals between each repetition. We collected data for blood lactate concentration ([La]) and Borg scale rate of perceived exertion (RPE) at the end of each repetition. The results obtained were: M RPET = 4.98, SD = 1.12 arbitrary units (A.U.) and M lactate threshold = 4.24, SD = 1.12 mmol.L-1, with [La] and RPE identified by the maximal deviation (Dmax) method without a significant difference (p > 0.05) and large correlations between DmaxLa and DmaxRPE at variables for time (r = 0.64), velocity (r = 0.67) and percentage of personal best time (PB) (r = 0.60). These results suggest that RPET is a good predictor of LT in young competitive swimmers.

Determinant Factors of the Match-Based Internal Load in Elite Soccer Players.

Purpose: To analyze the contribution of physical measures and external load in the match-based internal load of elite soccer players. Methods: Twenty-three elite soccer players (n = 23, age 26.69 ± 3.93 years, body mass 78.04 ± 5.03 kg, height 178.04 ± 5.19 cm, body fat 10.98 ± 1.25%) from a first division soccer team of the Brazilian Championship were evaluated first with anthropometric and physical measures (flexibility and muscle power of lower limbs), and after 24 hrs they were asked to perform an incremental treadmill test (VO2max and ventilatory thresholds). Subsequently, athletes were monitored for 6 weeks during nine official matches of a regional championship. On match days, the external load data (e.g., player load) were collected by triaxial accelerometers with GPS systems and post 30 min after the end of the match the internal load was assessed with the Session Rating of Perceived Exertion method (Session-RPE). Results: Our main findings showed significant contributions of the Player Load (r = .62, p < .001; 42.3%) and Anaerobic Threshold (r = - .199, p = .05, 17%) for the predictive model of Session-RPE. Conclusions: Physical measures and external load have a significant influence on the internal load in elite soccer players. Our findings suggest that sport scientists can use the Session-RPE as a low-cost method for prescribing and monitoring training loads, by the influence of physical measures and external load on the match-based internal load, in order to optimize athletes' performance.