The purpose of the present study was to investigate the pubertal characteristics of a group of specialist association football (soccer) players (N = 22) between the ages of 12.3 and 15.3 years. Pubertal status was assessed by direct observation of pubic hair (PH), and peak height velocity (PHV) was assessed using graphic procedures. The ages at which the various stages of PH were reached did not differ between playing positions or between players as a whole and the control group. The length of the interval between sequential stages of PH was about a year and between PH2 and PH5 was 2.5 years. Correlations between the age at PHV and each of the pubertal stages were generally high. It was concluded that the influence of participation in competitive association football had no significant effect on the attainment and progress of pubertal development beyond that expected by normal growth.
Alexander David Blackett, Adam B. Evans and David Piggott
between elite athlete and high-performance coach is as logical, simplistic and unproblematic as previously inferred. The aim of this study, therefore, is to provide the field with an original contribution by better understanding the experiences of whether fast-tracked coaches within men’s association
Iñigo Mujika, Juanma Santisteban, Paco Angulo and Sabino Padilla
A 7-week, 10-session individual training program was implemented with a youth elite football (soccer) player who had been underperforming because of poor aerobic fitness. The intervention focused on developing aerobic power and high lactate production and contributed to a 32.3% improvement in a football-specific performance test. The player was able to return to play and exceed expected performance levels during competitive match play.
Laura A. Garvican, Kristal Hammond, Matthew C. Varley, Christopher J. Gore, Francois Billaut and Robert J. Aughey
This study investigated the decrement in running performance of elite soccer players competing at low altitude and time course for abatement of these decrements.
Twenty elite youth soccer players had their activity profile, in a sea-level (SL) and 2 altitude (Alt, 1600 m, d 4, and d 6) matches, measured with a global positioning system. Measures expressed in meters per minute of match time were total distance, low- and high-velocity running (LoVR, 0.01–4.16 m/s; HiVR, 4.17–10.0 m/s), and frequency of maximal accelerations (>2.78 m/s2). The peak and subsequent stanza for each measure were identified and a transient fatigue index calculated. Mean heart rate (HR) during the final minute of a submaximal running task (5 min, 11 km/h) was recorded at SL and for 10 d at Alt. Differences were determined between SL and Alt using percentage change and effect-size (ES) statistic with 90% confidence intervals.
Mean HR almost certainly increased on d 1 (5.4%, ES 1.01 ± 0.35) and remained probably elevated on both d 2 (ES 0.42 ± 0.31) and d3 (ES 0.30 ± 0.25), returning to baseline at d 5. Total distance was almost certainly lower than SL (ES –0.76 ± 0.37) at d 4 and remained probably reduced on d 6 (ES –0.42 ± 0.36). HiVR probably decreased at d 4 vs SL (–0.47 ± 0.59), with no clear effect of altitude at d 6 (–0.08 ± 0.41). Transient fatigue in matches was evident at SL and Alt, with a possibly greater decrement at Alt.
Despite some physiological adaptation, match running performance of youth soccer players is compromised for at least 6 d at low altitude.
Martin Buchheit, Ben M. Simpson, Esa Peltola and Alberto Mendez-Villanueva
The aim of the present study was to locate the fastest 10-m split time (Splitbest) over a 40-m sprint in relation to age and maximal sprint speed in highly trained young soccer players. Analyses were performed on 967 independent player sprints collected in 223 highly trained young football players (Under 12 to Under 18). The maximal sprint speed was defined as the average running speed during Splitbest. The distribution of the distance associated with Splitbest was affected by age (X 2 3 = 158.7, P < .001), with the older the players, the greater the proportion of 30-to-40-m Splitbest. There was, however, no between-group difference when data were adjusted for maximal sprint speed. Maximal sprint speed is the main determinant of the distance associated with Splitbest. Given the important disparity in Splitbest location within each age group, three (U12-U13) to two (U14-U18) 10-m intervals are still required to guarantee an accurate evaluation of maximal sprint speed in young players when using timing gates.
Carlo Castagna, Matthew Varley, Susana C.A. Póvoas and Stefano D’Ottavio
To test the interchangeability of 2 match-analysis approaches for external-load detection considering arbitrary selected speeds and metabolic power (MP) thresholds in male top-level soccer.
Data analyses were performed considering match physical performance of 60 matches (1200 player cases) of randomly selected Spanish, German, and English first-division championship matches (2013–14 season). Match analysis was performed with a validated semiautomated multicamera system operating at 25 Hz.
During a match, players covered 10,673 ± 348 m, of which 1778 ± 208 m and 2759 ± 241 m were performed at high intensity, as measured using speed (≥16 km/h, HI) and metabolic power (≥20 W/kg, MPHI) notations. High-intensity notations were nearly perfectly associated (r = .93, P < .0001). A huge method bias (980.63 ± 87.82 m, d = 11.67) was found when considering MPHI and HI. Very large correlations were found between match total distance covered and MPHI (r = .84, P < .0001) and HI (r = .74, P < .0001). Player high-intensity decelerations (≥–2 m/s2) were very largely associated with MPHI (r = .73, P < .0001).
The speed and MP methods are highly interchangeable at relative level (magnitude rank) but not absolute level (measure magnitude). The 2 physical match-analysis methods can be independently used to track match external load in elite-level players. However, match-analyst decisions must be based on use of a single method to avoid bias in external-load determination.
Andrew Foskett, Ajmol Ali and Nicholas Gant
There is little evidence regarding the benefits of caffeine ingestion on cognitive function and skillful actions during sporting performance, especially in sports that are multifaceted in their physiological, skill, and cognitive demands.
To examine the influence of caffeine on performance during simulated soccer activity.
Twelve male soccer players completed two 90-min soccer-specific intermittent running trials interspersed with tests of soccer skill (LSPT). The trials were separated by 7 days and adhered to a randomized crossover design. On each occasion participants ingested 6 mg/kg body mass (BM) of caffeine (CAF) or a placebo (PLA) in a double-blind fashion 60 min before exercise. Movement time, penalties accrued, and total time were recorded for the LSPT. Physiological and performance markers were measured throughout the protocol. Water (3 ml/kg BM) was ingested every 15 min.
Participants accrued significantly less penalty time in the CAF trial (9.7 ± 6.6 s vs. PLA 11.6 ± 7.4 s; p = .02), leading to a significantly lower total time in this trial (CAF 51.6 ± 7.7 s vs. PLA 53.9 ± 8.5 s; p = .02). This decrease in penalty time was probably attributable to an increased passing accuracy in the CAF trial (p = .06). Jump height was 2.7% (± 1.1%) higher in the CAF trial (57.1 ± 5.1 cm vs. PLA 55.6 ± 5.1 cm; p = .01).
Caffeine ingestion before simulated soccer activity improved players’ passing accuracy and jump performance without any detrimental effects on other performance parameters.