A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players.

Deprez D, Buchheit M, Fransen J, Pion J, Lenoir M, Philippaerts RM, Vaeyens R.. A longitudinal study investigating the stability of anthropometry and soccer-specific endurance in pubertal high-level youth soccer players. J Sports Sci Med. 2015 May 8;14(2):418-26. eCollection 2015 Jun

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We investigated the evolution and stability of anthropometric and soccer-specific endurance characteristics of 42 high-level, pubertal soccer players with high, average and low yo-yo intermittent recovery test level 1 (YYIR1) baseline performances over two and four years. The rates of improvement were calculated for each performance group, and intra-class correlations were used to verify short- and long-term stability. The main finding was that after two and four years, the magnitudes of the differences at baseline were reduced, although players with high YYIR1 baseline performance still covered the largest distance (e.g., low from 703 m to 2126 m; high from 1503 m to 2434 m over four years). Furthermore, the YYIR1 showed a high stability over two years (ICC = 0.76) and a moderate stability over four years (ICC = 0.59), due to large intra-individual differences in YYIR1 performances over time. Anthropometric measures showed very high stability (ICCs between 0.94 to 0.97) over a two-year period, in comparison with a moderate stability (ICCs between 0.57 and 0.75) over four years. These results confirm the moderate-to-high stability of high-intensity running performance in young soccer players, and suggest that the longer the follow-up, the lower the ability to predict player’s future potential in running performance. They also show that with growth and maturation, poor performers might only partially catch up their fitter counterparts between 12 and 16 years. Key pointsYoung, high-level soccer players with a relatively low intermittent-endurance capacity are capable to catch up with their better performing peers after four years.Individual development and improvements of anthropometric and physical characteristics should be considered when evaluating young soccer players.


Football; field test; high-intensity intermittent performance; maturity status; talent development

Peak match speed and maximal sprinting speed in young soccer players: effect of age and playing position

Hani Al Haddad, Ben M. Simpson, Martin Buchheit, Valter Di Salvo and Alberto Mendez-Villanueva. Peak match speed and maximal sprinting speed in young soccer players: effect of age and playing position. IJSPP, 2015, In press.

Figure 1Figure 1. Data are presented as mean and 90% confidence interval for maximal sprinting speed (MSS, white circles), peak match speed (PMSAbs, gray circles) and PMSAbs as percentage of MSS (PMSRel, black circles).


In this study we assessed the relationship between peak match speed (PMS) and maximal sprinting speed in regard to age and playing positions. Maximal sprinting speed and absolute PMS (PMSAbs) were collected from 180 male youth soccer players (U13 to U17, 15.0 ± 1.2 yrs, 161.5 ± 9.2 cm and 48.3 ± 8.7 kg). The fastest 10-m split over a 40-m sprint was used to determine maximal sprinting speed. PMSAbs was recorded using a global positioning system and was also expressed as a percentage of maximal sprinting speed (PMSRel). Sprint data were compared between age groups and between playing positions. Results showed that regardless of age and playing positions, faster players were likely to reach higher PMSAbs and possibly lower PMSRel. Despite a lower PMSAbs compared with older groups (e.g., 23.4 ± 1.8 vs. 26.8 ± 1.9 km/h for U13 and U17, respectively, ES= 1.9 90% confidence limits (1.6;2.1)), younger players reached a greater PMSRel (92.0±6.3% vs. 87.2±5.7% for U13 and U17, respectively, ES= -0.8 90% CL (-1.0; -0.5)). Playing position also affected PMSAbs and PMSRel, as strikers were likely to reach higher PMSAbs (e.g., 27.0 ± 2.7 vs. 23.6 ± 2.2 km/h for strikers and central midfielder, respectively, ES= 2.0 (1.7;2.2)) and PMSRel (e.g., 93.6 ± 5.2% vs. 85.3 ± 6.5% for striker and central midfielder, respectively, ES= 1.0 (0.7;1.3)) compared with all other positions. Present findings confirm that age and playing positions affect the absolute and relative intensity of speed-related actions during matches.

Key words: youth players, soccer, sprinting speed, playing position

@HaniAlHaddad2 @benMsimpson

Effects of age, maturity and body dimensions on match running performance in highly-trained under 15 soccer players

More vs less mature

Buchheit & Mendez-Villanueva. Effects of age, maturity and body dimensions on match running performance in highly-trained under 15 soccer players. Journal of Sports Science, In press

For a discussion about the stats used in this study see the comments here: don’t trust % differences

The aim of the present study was to compare, in 36 highly-trained under 15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n=115 player-files). Total distance and distance covered >16 km/h (D>16 km.h-1) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen’s d for MSS: 0.5-1.0, likely to almost certain) and match running performances (D>16 km.h-1: 0.2-0.5, possibly to likely) than their younger, less mature and/or smaller team-mates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures vs. match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players’ maturity status when assessing their on-field playing performance.

Locomotor Performance in Highly-trained Young Soccer Players – Does Body Size Always Matter?

We all know that body dimensions affect athletic performance, especially in young players differing in maturation. However, how important is this effect is still unclear, and the available methods to account for differences in body dimensions have not been compared. In this study we compared the Aspire Qatari U15 players with the best french U15 players, and examined how their different body size affected their locomotor performance. The first interesting findings was to see how shorter (-7cm) and lighter (-10 kg) the Qatari are !! As you will also understand if you read all results in details, allometric scaling helps to account for these differences, but not always – body dimensions don’t explain everything ! Feedback appreciated, as always.

Screenshot - 9_11_2013 , 11_52_33 PM