Internal and External Training Load in Under-19 Versus Professional Soccer Players During The In-Season Period

This study aimed to compare the training load of a professional under-19 soccer team (U-19) to that of an elite adult team (EAT), from the same club, during the in-season period. Thirty-nine healthy soccer players were involved (EAT [n = 20]; U-19 [n = 19]) in the study which spanned four weeks. Training load (TL) was monitored as external TL, using a global positioning system (GPS), and internal TL, using a rating of perceived exertion (RPE). TL data were recorded after each training session. During soccer matches, players’ RPEs were recorded. The internal TL was quantified daily by means of the session rating of perceived exertion (session-RPE) using Borg’s 0–10 scale. For GPS data, the selected running speed intensities (over 0.5 s time intervals) were 12–15.9 km/h; 16–19.9 km/h; 20–24.9 km/h; >25 km/h (sprint). Distances covered between 16 and 19.9 km/h, > 20 km/h and >25 km/h were significantly higher in U-19 compared to EAT over the course of the study (p = 0.023, d = 0.243, small; p = 0.016, d = 0.298, small; and p = 0.001, d = 0.564, small, respectively). EAT players performed significantly fewer sprints per week compared to U-19 players (p = 0.002, d = 0.526, small). RPE was significantly higher in U-19 compared to EAT (p = 0.001, d = 0.188, trivial). The external and internal measures of TL were significantly higher in the U-19 group compared to the EAT soccer players. In conclusion, the results obtained show that the training load is greater in U19 compared to EAT

Relationship of Pre-season Training Load With In-Season Biochemical Markers, Injuries and Performance in Professional Soccer Players

IntroductionThere is controversy in the literature in regards of the link between training load and injury rate. Thus, the aims of this non-interventional study were to evaluate relationships between pre-season training load with biochemical markers, injury incidence and performance during the first month of the competitive period in professional soccer players.Materials and MethodsHealthy professional soccer players were enrolled in this study over two pre-season periods. Data sets were available from 26 players during the first season (2014–2015) and 24 players during the second season (2015–2016) who completed two pre-season periods (6 weeks each). External training load was assessed from all athletes during training using Global Positioning System (GPS). Internal training load was monitored after each training session using rate of perceived exertion (RPE). Before and after each pre-season, blood samples were taken to determine plasma lactate dehydrogenase (LDH), creatine kinase (CK) and C-reactive protein (CRP). Injury incidence and overall performance (ranking of the team after the first five official games of the championship) were recorded for both seasons separately.ResultsThere was no statistically significant difference in mean RPE values of the two-preparation periods (2737 ± 452 and 2629 ± 786 AU, p = 0.492). The correlational analysis did not reveal significant associations between internal and external training load (RPE and GPS data) and biological markers. There was a significant positive correlation between RPE and LDH during the 2015/2016 season (r = 0.974, p = 0.001). In addition, a significant negative correlation was found between total distance >20 km/h and CRP during the 2015–2016 season (r = -0.863, p = 0.027). The injury rates for the two seasons were 1.76 and 1.06 per 1000 h exposure for the 2014–2015 and 2015–2016 seasons, respectively (p = 0.127).ConclusionOur study showed that pre-season training load is not associated with overall team performance. This association is most likely multifactorial and other factors (e.g., technical and tactical level of the team, opponents, environment) may play an important role for the collective team performance. Our findings may help coaches to better prepare their athletes during pre-season

Sprint and jump performances in highly trained young soccer players of different chronological age: Effects of linear VS. CHANGE-OF-DIRECTION sprint training

International audienceOBJECTIVE: The aim of this study was to examine the effects of two different sprint-training regimes on sprint and jump performances according to age in elite young male soccer players over the course of one soccer season. METHODS: Players were randomly assigned to two training groups. Group 1 performed systematic change-of-direction sprints (CODST, U19 [n = 9], U17 [n = 9], U15 [n = 10]) while group 2 conducted systematic linear sprints (LST, U19 [n = 9], U17 [n = 9], U15 [n = 9]). Training volumes were similar between groups (40 sprints per week x 30 weeks = 1200 sprints per season). Pre and post training, all players performed tests for the assessment of linear and slalom sprint speed (5-m and 10-m), countermovement jump, and maximal aerobic speed performance. RESULTS: For all physical fitness measures, the baseline-adjusted means data (ANCOVA) across the age groups showed no significant differences between LST and CODST at post (0.061 < p < 0.995; 0.0017 < d < 1.01). The analyses of baseline-adjusted means for all physical fitness measures for U15, U17, and U19 (LST vs. CODST) revealed no significant differences between LST and CODST for U15 (0.213 < p < 0.917; 0.001 < d < 0.087), U17 (0.132 < p < 0.976; 0.001 < d < 0.310), and U19 (0.300 < p < 0.999; 0.001 < d < 0.049) at post. CONCLUSIONS: The results from this study showed that both, LST and CODST induced significant changes in the sprint, lower limbs power, and aerobic performances in young elite soccer players. Since no significant differences were observed between LST and CODST, the observed changes are most likely due to training and/or maturation. Therefore, more research is needed to elucidate whether CODST, LST or a combination of both is beneficial for youth soccer athletes’ performance development

Timing of Resistance Training During Ramadan Fasting and Its Effects on Muscle Strength and Hypertrophy

International audiencePURPOSE: During Ramadan month, Muslims often continue training to maintain their muscle performance. However, trainers should stress the importance of the time of day chosen for practicing resistance training (RT) during Ramadan fasting to avoid health and performance alteration. Thus, this study aimed to investigate the effects of the timing of RT during Ramadan intermittent fasting (RIF) on muscle strength and hypertrophy in healthy male adults. METHODS: Forty men were randomly allocated to 2 matched groups: 20 practicing whole-body RT in the late afternoon in a fasted state and 20 training in the late evening in a fed state (FED). Both groups performed 4 days per week of whole-body RT (∼75%-85% 1-repetition maximum, 12 repetitions/3-4 sets) during RIF. Anthropometric measurements and 1-repetition-maximum test for the squats, deadlift, and bench press were measured. A cross-sectional area of the quadriceps and biceps brachii was examined using ultrasound scans. All measurements were taken at 4 time points: 24 hours before the start of Ramadan, on the 15th day of Ramadan, on the 29th day of Ramadan, and 21 days after Ramadan. RESULTS: Post hoc tests indicated significant preimprovement to postimprovement in FED at the 29th day of Ramadan for the 1-repetition-maximum test for the squats (P = .02; effect size = 0.21) and deadlift (P = .03; effect size = 0.24) when compared to 24 hours before the start of Ramadan. No significant changes were observed in the fasted-state group or for cross-sectional area for both groups. CONCLUSIONS: Practicing RT during RIF appears not to have adverse effects on muscle hypertrophy and strength no matter whether it is practiced in FED or fasted state. However, RT had greater effects on muscle strength when applied in FED. Our findings suggest that training sessions should be scheduled after breaking the fast during Ramadan

The Effects of Combined Versus Single-Mode Resistance and Repeated Sprint Training on Physical Fitness, Hematological Parameters, and Plasma Volume Variations in Highly Trained Soccer Players

International audienceObjective: We examined the effects of eight weeks of single-mode resistance, repeated sprint training, and the combination of the two programs on selected measures of physical fitness (muscle power, speed, and body composition), hematological parameters, and plasma volume variations in highly trained soccer players. Sixty male soccer players from the Tunisian national Ligue were randomly allocated to a resistance training group (RTG), a repeated sprint training group (RSTG), a combined resistance and repeated sprint training group (CTG), or an active control group (CG, soccer training only). The training volumes were similar between groups. Before and after training, we examined body composition, squat jump (SJ), countermovement jump (CMJ), sprint 30 m (S30), repeated-sprint sequences (RSSs), hematocrit, hemoglobin, mean hemoglobin concentration (MHC), and plasma volume. Significant group-by-time interactions were recorded for the RSS indices, SJ, and S30 (p < 0.039], 0.1< ηp2 < 0.49]), as well as the hematological parameters (p = 0.0001–0.045, 0.11 < ηp2 < 0.46). In terms of physical fitness, using post hoc tests, the CTG showed significantly greater gains compared to the RSTG, RTG, and the CG on the best time index of the RSSs (p = 0.008; d = 4.1), SJ (p = 0.004; d = 4.18) and 30 m linear sprint time (p = 0.008; d = 3.84). Body fat percentage also decreased significantly in the CTG compared to all other groups (p < 0.005, 0.21 < d< 0.35). Regarding hematological parameters (i.e., hemoglobin and hematocrit), the CTG, RSTG, and RTG showed significant decreases (p < 0.05) in their hemoglobin and hematocrit values compared to the CG (p < 0.05, 0.11 < d< 2.22]). Eight weeks of combined training compared to single-mode training was found to be more effective in improving fitness measures in highly trained soccer players. However, there appeared to be no consensus regarding the effect of single and combined repeated-sprint and resistance training on the hematological system

Gastrointestinal Hormones, Morphological Characteristics, and Physical Performance in Elite Soccer Players

International audiencePurpose: To determine the relationship between gastrointestinal hormones (leptin, glucagon-like peptide-1), ghrelin, cholecystokinin, peptide YY, morphological characteristics, and physical performances in elite soccer players. Methods: Q2 Twenty-two elite male soccer players (age = 23.1 [2.7] y, height = 177.0 [0.1] cm, weight = 70.2 [2.9] kg, body mass index = 22.1 [1.8] kg/m(2)) completed 3-day food records each week during the 5-week training period. Blood samples were drawn after an overnight fast before and after preseason training to assess gastrointestinal hormones (leptin, glucagon-like peptide-1, ghrelin, cholecystokinin, and peptide YY). Continuous analysis of the training load was used during the training period. Preintervention and postintervention tests assessed jumping (countermovement jump), sprinting (10, 20, and 30 m), and endurance fitness (the Yo-Yo Intermittent Recovery Test Level 1 [YYIRT1]) levels. Results: Preseason training decreased body mass index (P = .001; effect size [ES] = 0.183) and body fat percentage (P = .001; ES = 0.516). There were increases in countermovement jump (P = .032; ES = 0.215), 20-(P = .016; ES = 0.195) and 30-m sprints (P = .001; ES = 0.188), and YYIRT1 performance (P = .001; ES = 0.9). Levels of cholecystokinin, peptide YY, and ghrelin did not change during preseason training, although changes in leptin (P = .001; ES = 0.41) and glucagon-like peptide-1 levels (P = .039; ES = 0.606) were recorded. Leptinemia correlated with anthropometric parameters (body mass index, r= .77, P = .001; percentage of body fat, r = .67, P = .006) and the total distance covered during the YYIRT1 (r= -.54; P = .03). Conclusion: Changes in morphological parameters and physical performance in elite-level male soccer players are related to variations in selected gastrointestinal hormones