Navigating the Complex Pathway of Youth Athletic Development: Challenges and Solutions to Managing the Training Load of Youth Team Sport Athletes

The development of a youth team sport athlete is a complex process. This article outlines challenges that may restrict the optimal balance between training and recovery and provide solutions to help practitioners overcome these challenges. To facilitate positive youth athletic development, training aims must be aligned between stakeholders to synchronize periods of intensified training and recovery. Within- and between-athlete variations in weekly training load must be managed and practitioners should attempt to ensure the intended load of training equals the load perceived by the athlete. Furthermore, practitioners should be cognizant of the athletes' nonsport-related stressors to enable both academic and sporting pursuits. Although each of these challenges adds intricacy, they may be overcome through collaboration, monitoring, and, if necessary, the modification of the athletes' training load

Мультимодальное лечение двусторонних опухолей почек как способ улучшения онкологических и функциональных результатов: клинический случай и обзор литературы

Почечно-клеточный рак (ПКР) может поражать как одну, так и обе почки. Описаны случаи мультифокального поражения одной почки. Синхронные и метахронные двусторонние опухоли почек представляют серьезную медицинскую проблему, которая должна быть решена наилучшим путем с точки зрения радикальности лечения и максимального сохранения функции почек. Мы представляем описание клинического случая метахронного ПКР с рецидивом в ипсилатеральной и контралатеральной почке. У этого пациента было использовано несколько методик, направленных на сохранение функции нефронов. Был проведен обзор литературы по заболеваемости, лечению и исходам синхронного и метахронного ПКР, а также по вариантам лечения, доступным таким больным. Мы использовали сочетание открытых и малоинвазивных методик, направленных на сохранение функции почек, включая открытую резекцию почки и лапароскопическую криотерапию. По прошествии 5 лет наблюдения пациент не имеет признаков болезни и ему не требуется проведение гемодиализа. Двусторонние опухоли почек встречаются нередко и могут представлять значительную проблему при выборе методов лечения с учетом необходимости сохранения функции почек. Результаты лечения можно улучшить при использовании мультимодального подхода, включающего малоинвазивные и открытые процедуры.

The influence of training load, exposure to match play and sleep duration on daily wellbeing measures in youth athletes

This study assessed the influence of training load, exposure to match play and sleep duration on two daily wellbeing measures in youth athletes. Forty-eight youth athletes (age 17.3 ± 0.5 years) completed a daily wellbeing questionnaire (DWB), the Perceived Recovery Status scale (PRS), and provided details on the previous day’s training loads (TL) and self-reported sleep duration (sleep) every day for 13 weeks (n = 2727). Linear mixed models assessed the effect of TL, exposure to match play and sleep on DWB and PRS. An increase in TL had a most likely small effect on muscle soreness (d = −0.43;± 0.10) and PRS (d = −0.37;± 0.09). Match play had a likely small additive effect on muscle soreness (d = −0.26;± 0.09) and PRS (d = −0.25;± 0.08). An increase in sleep had a most likely moderate effect on sleep quality (d = 0.80;± 0.14); a most likely small effect on DWB (d = 0.45;± 0.09) and fatigue (d = 0.42;± 0.11); and a likely small effect on PRS (d = 0.25;± 0.09). All other effects were trivial or did not reach the pre-determined threshold for practical significance. The influence of sleep on multiple DWB subscales and the PRS suggests that practitioners should consider the recovery of an athlete alongside the training stress imposed when considering deviations in wellbeing measures

Collision activity during training increases total energy expenditure measured via doubly labelled water

Purpose: Collision sports are characterised by frequent high intensity collisions that induce substantial muscle damage, potentially increasing the energetic cost of recovery. Therefore, this study investigated the energetic cost of collision-based activity for the first time across any sport. Methods: Using a randomised crossover design, six professional young male rugby league players completed two different five-day pre-season training microcycles. Players completed either a collision (COLL; 20 competitive one-on-one collisions) or non-collision (nCOLL; matched for kinematic demands, excluding collisions) training session on the first day of each microcycle, exactly seven days apart. All remaining training sessions were matched and did not involve any collision-based activity. Total energy expenditure was measured using doubly labelled water, the literature gold standard. Results: Collisions resulted in a very likely higher (4.96 ± 0.97 MJ; ES = 0.30 ±0.07; p=0.0021) total energy expenditure across the five-day COLL training microcycle (95.07 ± 16.66 MJ) compared with the nCOLL training microcycle (90.34 ± 16.97 MJ). The COLL training session also resulted in a very likely higher (200 ± 102 AU; ES = 1.43 ±0.74; p=0.007) session rating of perceived exertion and a very likely greater (-14.6 ± 3.3%; ES = -1.60 ±0.51; p=0.002) decrease in wellbeing 24h later. Conclusions: A single collision training session considerably increased total energy expenditure. This may explain the large energy expenditures of collision sport athletes, which appear to exceed kinematic training and match demands. These findings suggest fuelling professional collision-sport athletes appropriately for the "muscle damage caused” alongside the kinematic “work required”. Key words: Nutrition, Recovery, Contact, Rugb

Role of the monocarboxylate transporter MCT1 in the uptake of lactate during active recovery

Purpose We assessed the role of monocarboxylate transporter 1 (MCT1) on lactate clearance during an active recovery after high-intensity exercise, by comparing genetic groups based on the T1470A (rs1049434) MCT1 polymorphism, whose influence on lactate transport has been proven. Methods Sixteen young male elite field hockey players participated in this study. All of them completed two 400 m maximal run tests performed on different days, followed by 40 min of active or passive recovery. Lactate samples were measured immediately after the tests, and at min 10, 20, 30 and 40 of the recoveries. Blood lactate decreases were calculated for each 10-min period. Participants were distributed into three groups according to the T1470A polymorphism (TT, TA and AA). Results TT group had a lower blood lactate decrease than AA group during the 10?20 min period of the active recovery (p = 0.018). This period had the highest blood lactate for the whole sample, significantly differing from the other periods (p ? 0.003). During the passive recovery, lactate declines were constant except for the 0?10-min period (p ? 0.003), suggesting that liver uptake is similar in all the genetic groups, and that the difference seen during the active recovery is mainly due to muscle lactate uptake. Conclusions These differences according to the polymorphic variant T1470A suggest that MCT1 affects the plasma lactate decrease during a crucial period of active recovery, where the maximal lactate amount is cleared (i.e. 10?20 min period)

No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes

There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES) was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners), from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games) and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002), even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0), all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance performance but also of compromised cardiac functions and cardiometabolic diseases

The peak duration-specific locomotor demands and concurrent collision frequencies of European Super League rugby

Understanding the most demanding passages of European Super League competition can optimise training prescription. We established positional and match half differences in peak relative distances (m·min −1) across durations, and the number of collisions, high-speed- and very-high-speed-distance completed in the peak 10 min period. Moving-averages (10 s, 30 s, 1 min, 5 min, 10 min) of instantaneous speed (m·s −1) were calculated from 25 professional rugby league players during 25 matches via microtechnology. Maximal m·min −1 was taken for each duration for each half. Concurrently, collisions (n), high-speed- (5 to 7 m·s −1; m) and very-high-speed-distance (&gt; 7 m·s −1; m) were coded during each peak 10 min. Mixed-effects models determined differences between positions and halves. Aside from peak 10 s, trivial differences were observed in peak m·min −1 between positions or halves across durations. During peak 10 min periods, adjustables, full- and outside-backs ran more at high-speed and very-high-speed whilst middle- and edge-forwards completed more collisions. Peak m·min −1 is similar between positional groups across a range of durations and are maintained between halves of the match. Practitioners should consider that whilst the overall peak locomotor “intensity” is similar, how they achieve this differs between positions with forwards also exposed to additional collision bouts. </p

Are rugby league players involved in more tackles than normal, prior to an injury sustained during a tackle event?

Rugby league has a relatively high injury risk, with the tackle having the greatest injury propensity. The number of tackles players engage in, prior to injurious tackles may influence injury risk, which has yet to be investigated. Therefore, this study investigated if rugby league players are involved in more tackles (as either tackler or ball carrier) (i) in the 10 minutes, or (ii) 1-min periods prior to an injurious tackle-event, (iii) differences for ball carriers vs. tacklers, and (iv) forwards vs. backs. Video analysis was utilised to quantify the number and rate of tackles in the 10-min periods prior to 61 tackle-related injuries. One thousand two hundred and eighty 10-min periods where players were not injured, were used as matched-controls. Generalized mixed linear models were used to analyse mean total and rate for tackles. Injured players were involved in significantly fewer tackles during the 10-min period, yet significantly more tackles during the final minute prior to the injurious tackle-event, compared to non-injured players. There were no differences between ball carriers vs. tacklers during the 10-min period. Both injured position groups were involved in significantly more tackles in the final minute. Additional match data sources are needed to further inform injury preventive strategies of tackle events

Are rugby league players involved in more tackles than normal, prior to an injury sustained during a tackle event?

Rugby league has a relatively high injury risk, with the tackle having the greatest injury propensity. The number of tackles players engage in, prior to injurious tackles may influence injury risk, which has yet to be investigated. Therefore, this study investigated if rugby league players are involved in more tackles (as either tackler or ball carrier) (i) in the 10 minutes, or (ii) 1-min periods prior to an injurious tackle-event, (iii) differences for ball carriers vs. tacklers, and (iv) forwards vs. backs. Video analysis was utilised to quantify the number and rate of tackles in the 10-min periods prior to 61 tackle-related injuries. One thousand two hundred and eighty 10-min periods where players were not injured, were used as matched-controls. Generalized mixed linear models were used to analyse mean total and rate for tackles. Injured players were involved in significantly fewer tackles during the 10-min period, yet significantly more tackles during the final minute prior to the injurious tackle-event, compared to non-injured players. There were no differences between ball carriers vs. tacklers during the 10-min period. Both injured position groups were involved in significantly more tackles in the final minute. Additional match data sources are needed to further inform injury preventive strategies of tackle events

A multi-nation examination of the fatigue and recovery time course during the inaugural Under-18 Six Nations rugby union competition

The purpose of this study was to investigate the neuromuscular and perceptual fatigue responses of elite rugby players during the inaugural Under-18 (U18) Six Nations Festival. One hundred and thirty-three male players from five national squads (73 forwards, 60 backs) were examined during the competition. Each national squad was involved in three matches separated by 96 h each. Over the competition, players completed a daily questionnaire to monitor perceived well-being (WB) and performed daily countermovement jumps (CMJ) to assess neuromuscular function (NMF). Reductions in WB were substantial 24 h after the first and second match in forwards (d=0.77±0.21, pd=0.84±0.22, pd=0.89±0.22, p d=0.58±0.23, pd=0.31±0.15, p=0.001; d=0.25±0.17, p=0.0205) and backs (d=0.40±0.17, p=0.0001; d=0.28±0.17, p=0.0062) and recovered at 48 h after match-play. Average WB and CMJ height attained complete recovery within matchday cycles in the investigated international competition. The findings of this study can be useful for practitioners and governing bodies involved with fixture scheduling and training prescription during competitive periods