The effect of concurrent training organisation in youth elite soccer players

Purpose: This study compared the adaptive responses to two concurrent training programmes frequently used in professional soccer. Methods: Fifteen youth soccer players (17.3 ± 1.6 years, 1.82 ± 0.06 m, 77.0 ± 7.3 kg; VO peak, 62.0 ± 4.7 ml kg min) who compete in the English Premier League volunteered for this study. In addition to completing their habitual training practices, the participants were asked to alter the organisation concurrent training by performing strength (S) training either prior to (S + E, n = 8) or after (E + S, n = 7) soccer-specific endurance training (E) 2d wk for 5 wk. Results: With the exception of 30 m sprint, IMVC PF, quadriceps strength (60°/s, 180°/s, 120°/s) pooled data revealed training effects across all other performances measures (P < 0.05). Whilst ANCOVA indicated no significant interaction effects for training condition, the difference between the means divided by the pooled standard deviation demonstrated large effect sizes in the E + S condition for in HBS 1-RM [S + E vs E + S; −0.54 (9.6 %) vs −1.79 (19.6 %)], AoP-M [−0.72 (7.9 %) vs −1.76 (14.4 %)], SJ [−0.56, (4.4 %), vs −1.08, (8.1 %)], IMVC-LR; [−0.50, (20.3 %) vs −1.05 (27.3 %)], isokinetic hamstring strength 60°/s [−0.64, (12.2 %) vs −0.95 (19.2 %)], 120°/s [−0.78 (27.9 %) vs −1.55 (23.3 %)] and isokinetic quadriceps strength 180°/s  [−0.23 (2.5 %) vs −1.52 (13.2 %)]. Conclusion: Results suggest the organisation of concurrent training, recovery time allocated between training bouts and the availability nutrition may be able to modulate small but clinically significant changes in physical performance parameters associated with match-play. This may have practical implications for practitioners who prescribe same day concurrent training protocols

Hormonal responses during two different concurrent-training trials in youth elite soccer players: does changing the organisation of training impact the hormonal response to concurrent exercise?

BACKGROUND: There are no data describing the acute hormonal responses to concurrent-training programmes in youth elite soccer players. Therefore, the aim of this study was to describe the total testosterone (T), cortisol (C), and growth hormone (hGH) responses during two same-day concurrent-training (CT) trials in elite soccer players. METHODS: n=13 youth elite players (age: 17.0±0.2 yrs; height, 1.80±0.07 m; body mass, 73.1±5.7 kg; O2 max, 64.4±4.8ml-1.kg-1.min-1) from an English premier league soccer club completed two CT trials. ‘Trial 1’ (CT1); E (10.30h) followed by S (14.00h) and Trial 2 (CT2); strength-training (S) 09.00h followed by a soccer-specific endurance-training session (E) at 10.30h. Venous blood samples were collected at 5 time-points around training and food intake (T1; 08.00h, T2; 09.45h, T3; 12.30h, T4; 13.45h and T5; 15.15h) and analysed for T (nmol/L) and C (nmol/L) and hGH (ug/L). RESULTS: There was no main effects found between exercise conditions for any hormones (T; P=0.22, C; P=0.07, hGH; P=0.21). Effect size analysis revealed a moderate effect for T at T3 (ES=0.63, CT1; 18.4±3.8, CT2; 15.7±4.7 nmol/L-1). A moderate effect for T area under the curve (AUC) was observed between conditions (CT1; 300±76 versus CT2; 244 ± 81 [AU]; ES=0.71). A moderate effect was apparent for C concentrations T4 in (ES=-0.95, CT1; 230±69, CT2; 314±105 nmol/L-1). Moderate effect sizes were observed at T3 and T4 (ES=0.82, CT1; 1.28±1.17, CT2; 0.47±0.75, ES=0.72, CT1; 0.11±0.05, CT2; 0.07±0.06 ug/L-1 respectively). A moderate effect for hGH AUC was observed between trials (CT1; 14±11 versus CT2; 5±9; [AU], ES=-1.08). CONCLUSIONS: The organisation of the concurrent-training protocols used in this study has a negligible impact upon the acute T, C and hGH in youth elite soccer players

Male Flat Jockeys Do Not Display Deteriorations in Bone Density or Resting Metabolic Rate in Accordance With Race Riding Experience: Implications for RED-S.

Despite consistent reports of poor bone health in male jockeys, it is not yet known if this is a consequence of low energy availability or lack of an osteogenic stimulus. Given the rationale that low energy availability is a contributing factor in low bone health, we tested the hypothesis that both hip and lumbar bone mineral density (BMD) should progressively worsen in accordance with the years of riding. In a cross-sectional design, male apprentice (n=17) and senior (n=14) jockeys (matched for body mass and fat free mass) were assessed for hip and lumbar spine BMD as well as both measured and predicted resting metabolic rate (RMR). Despite differences (P0.05) in hip (-0.9 ± 1.1 v -0.8 ± 0.7) and lumbar Z-scores (-1.3 ± 1.4 v -1.5 ± 1) or measured RMR (1459 ± 160 v 1500 ± 165 kcal.d-1) between apprentices and senior jockeys, respectively. Additionally, years of race riding did not demonstrate any significant correlations (P>0.05) with either hip or lumbar spine BMD. Measured RMR was also not different (P>0.05) from predicted RMR in either apprentice (1520 ± 44 kcal.d-1) or senior jockeys (1505 ± 70 kcal.d-1). When considered with previously published data examining under-reporting of energy intake and direct assessments of energy expenditure, we suggest that low BMD in jockeys is not due to low energy availability per se, but rather, the lack of an osteogenic stimulus associated with riding

Regulation of Muscle Glycogen Metabolism during Exercise: Implications for Endurance Performance and Training Adaptations.

Since the introduction of the muscle biopsy technique in the late 1960s, our understanding of the regulation of muscle glycogen storage and metabolism has advanced considerably. Muscle glycogenolysis and rates of carbohydrate (CHO) oxidation are affected by factors such as exercise intensity, duration, training status and substrate availability. Such changes to the global exercise stimulus exert regulatory effects on key enzymes and transport proteins via both hormonal control and local allosteric regulation. Given the well-documented effects of high CHO availability on promoting exercise performance, elite endurance athletes are typically advised to ensure high CHO availability before, during and after high-intensity training sessions or competition. Nonetheless, in recognition that the glycogen granule is more than a simple fuel store, it is now also accepted that glycogen is a potent regulator of the molecular cell signaling pathways that regulate the oxidative phenotype. Accordingly, the concept of deliberately training with low CHO availability has now gained increased popularity amongst athletic circles. In this review, we present an overview of the regulatory control of CHO metabolism during exercise (with a specific emphasis on muscle glycogen utilization) in order to discuss the effects of both high and low CHO availability on modulating exercise performance and training adaptations, respectively

An Intensive Winter Fixture Schedule Induces a Transient Fall in Salivary IgA in English Premier League Soccer Players

We examined the effects of an intensive fixture schedule on salivary IgA (SIgA) concentration in professional soccer players from the English Premier League. Salivary samples were obtained from 21 males who participated in 7 games over a 30-day period during December 2013 and January 2014 (games 1-5 occurred in a 15-day period). Salivary-IgA decreased (P 0.05) from game 1 (91 ± 18 and 99 ± 21 μg.mL-1, respectively). Data demonstrate for the first time that a congested winter fixture schedule induces detectable perturbations to mucosal immunity in professional soccer players

Anthropometric and Performance Characteristics of Elite Hurling Players

The purpose of the present study was to examine variations in the anthropometric and performance characteristics of elite hurling players in relation to playing position. Forty-one male, elite intercounty hurlers (25 ± 4 years), 4 goalkeepers, 8 full-backs, 8 halfback, 6 midfielders, 8 half-forwards and 7 full-forwards underwent measurements of standard anthropometric (stature, body mass, sum of five skinfolds and adipose tissue percentage estimates (%AT)) and performance characteristics (counter-movement jump (CMJ), CMJ peak power, CMJ relative peak power, 5-, 10-, 20-m sprint times and estimated V•O2max) during the later stages of the competitive season. A clear hierarchical anthropometric profile is evident with goalkeepers being the taller (184.3 ± 3.7 m), possessing the highest body mass (88.7 ± 5.7 kg) and adiposity (13.2 ± 3.1 %AT) than their outfield colleagues. Half-backs (47.4 ± 2.4 cm) and half-forwards (50.7 ± 5.9 cm) produced the highest CMJ scores; a similar profile was evident for sprint times. Midfielders (60.1 ± 1.4 mL.kg-1.min-1) exhibited a significantly (p<0.05) greater maximal oxygen uptake than all other playing positions. Differences in the anthropometric and performance characteristics of other playing positions whilst evident were non-significant. This study provides novel data, as it is the first report to present normative anthropometric and performance data for elite hurling players which to date has not been present in the literature. The enhanced maximal oxygen uptake in midfield players is likely due to different performance, technical and tactical demands associated with this position

Prevalence, Severity and Potential Nutritional Causes of Gastrointestinal Symptoms during a Marathon in Recreational Runners.

The purpose of the present study was to investigate the prevalence of gastrointestinal symptoms (GIS) amongst recreational runners during a marathon race, and potential nutritional factors that may contribute. Recreational runners of the 2017 Liverpool (n = 66) and Dublin (n = 30) marathons were recruited. GIS were reported post-marathon and we considered GIS in the 7 days prior to the marathon and during the marathon using the Gastrointestinal Symptom Rating Scale (GSRS). Nutritional intake was recorded using food diaries for the day before the race, morning of the race, and during the race; 43% of participants reported moderate (&ge;4) GIS in the 7 days prior to the marathon and 27% reported moderate symptoms during the marathon with most common symptoms being flatulence (16%) during training, and nausea (8%) during the marathon race. Correlations between all nutritional intake and GIS were not statistically significant (p > 0.05). There were significant correlations between total GIS score (r = 0.510, p < 0.001), upper GIS score (r = 0.346, p = 0.001) and lower GIS score (r = 0.483, p < 0.001) in training and during the marathon. There appears to be a modest prevalence of GIS in recreational runners, in the week prior to a marathon and during marathon running, although there was no association with nutritional intake before or during the race

The Work-Rate of Elite Hurling Match-Play

This study describes the global work-rate of elite hurling match-play and the influence which positional difference has on workrate is considered. The movement of ninety-four players was recorded using global positioning system, sampling at 4 Hz in a total of 12 games. Data were classified according to the positional line on the field and period of the match. The total and high-speed distance of match-play was 7,617 6 1,219 m (95% confidence interval [CI], 7,367–7,866) and 1,134 6 358 m (95% CI, 1,060–1,206), respectively. The maximum speed attained was 29.8 6 2.3 km.h-1 with a mean speed of 6.1 6 1 kmh 21. The second {271 6 107 m (p = 0.001; effect size [ES] = 0.25)}, third (278 6 118 m [p = 0.001; ES = 0.21]), and fourth quarter (255 6 108 m [p = 0.001; ES = 0.31]) high-speed running distance differed significantly from that of the first quarter (330 6 120 m). There was a significant difference in total (p = 0.001; ES = 0.01–0.85), high-speed running (p = 0.001; ES = 0.21–0.76), and sprint (p = 0.013; ES = 0.01–0.39) distance across the positions, with midfielders undertaking the highest volume of work, followed by the half-forward and half-back lines and finally the full-forward and full-back lines. A decrease in high-speed running distance seems to occur through out the game and in particular at the latter stages of each half. Distinct positional work profiles are evident. The present finding provide a context on which training which replicates the work-rate of match-play may be formulated, thus helping to improve the physical preparation of elite players

Training duration may not be a predisposing factor in potential maladaptations in talent development programmes that promote early specialisation in elite youth soccer

Purpose To determine whether training duration is a predisposing factor in potential maladaptations in talent development programmes that promote early specialisation in elite youth soccer. Methods Training times and type of 184 elite soccer players, from the under-9 to under-21 age groups (age 9.4 to 18.4 yrs; stature 1.38 to 1.82 m; body mass 32.2 to 76.2 kg) were recorded. Results Total training time progressively increased between the under-9 (268 ± 25 min/week) and under-14 (477 ± 19 min/week) groups with the majority of training time (96.5 ± 3.9%) consisting of soccer training and matches. Total training time then subsequently reduced from under-14 to under-15 (266 ± 77 min/week) groups, with no differences in training time between under-15 and under-21. Only under-15 to under-21 players completed resistance training; this inclusion coincided with a reduction in soccer training and match play when compared to time spent in these activities for younger groups (73.8 ± 3.2% of total training). Conclusion Data suggest that although the majority of training is focused on technical development, the training duration as a whole is unlikely to contribute to potential maladaptations in talent development programmes in elite youth soccer

GB Apprentice Jockeys Do Not Have the Body Composition to Make Current Minimum Race Weights: Is It Time to Change the Weights or Change the Jockeys?

Flat jockeys in Great Britain (GB) are classified as apprentices if they are aged less than 26 years and/or have ridden less than 95 winners. To gain experience, apprentices are allocated a weight allowance of up to 7 lb (3.2 kg). Given that there is no off-season in GB flat horseracing, jockeys are required to maintain their racing weight all year round. In light of recent work determining that current apprentices are considerably heavier than previous generations and that smaller increases have been made in the minimum weight, the aim of this study was to assess if the minimum weight in GB was achievable. To make the minimum weight (50.8 kg) with the maximal weight allowance requires a body mass of ∼46.6 kg while maintaining a fat mass >2.5 kg (the lowest fat mass previously reported in weight-restricted males). Thirty-two male apprentice jockeys were assessed for body composition using dual-energy X-ray absorptiometry. The mean (SD) total mass and fat mass were 56 (2.9) kg and 7.2 (1.8) kg, respectively. Given that the lowest theoretical body mass for this group was 51.2 (2.3) kg, only one of 32 jockeys was deemed feasible to achieve the minimum weight with their current weight allowance and maintaining fat mass >2.5 kg. Furthermore, urine osmolality of 780 (260) mOsmol/L was seen, with 22 (out of 32) jockeys classed as dehydrated (>700 mOsmols/L), indicating that body mass would be higher when euhydrated. Additionally, we observed that within new apprentice jockeys licensed during this study (N = 41), only one jockey was able to achieve the minimum weight. To facilitate the goal of achieving race weight with minimal disruptions to well-being, the authors’ data suggest that the minimum weight for GB apprentices should be raised