: influence of birth month and effect of specific training S. Boyas, T. Hervéou, A. Rahmani, S. Durand Laboratory «Movement, Interactions, Performance» EA 4334 School of Sports Sciences, University of Le Mans InternationalCongress of Sciences and Football Valenciennes March 1 4, 2016 www.mip.univ-nantes.fr Sebastien.Boyas@univ lemans.fr
Soccer and physical skills Technical and tactical skills crucial Physical skills mandatory / high level Reilly et al., 2000 Optimal physical skills Relative intensity efforts Training loads Delay performance / fatigue Mendez Villanueva et al., 2013
Soccer and physical skills Sprints / soccer game 96% < 30 m 49% < 10 m Stolen et al., 2003 Acceleration Maximal running speed Power Hoff, 2005; Taskin, 2008 Assessed during players selection
Maturation and physical skills Training sessions, competitions Young athletes grouped / chronological age Soccer: age groups include 2 years of birth 2014 2015 Season U15 : players born after 01/01/2000 and before 31/12/2001 Teammates or opponents may have almost 2 years of age difference
Relative age effect (RAE) Impact on physical skills Players born earlier in the year Are taller, have longer lower limbs Bucheit at al., 2013; Gil et al., 2013; Torres Unda et al., 2013; Carling et al., 2009 Tend to perform better in speed and agility tests Gil et al., 2013; Carling et al., 2009 Perform better in endurance tests Gil et al., 2013
Relative age effect (RAE) Players selection Young soccer teams (U14 to U18) Wattie et al., 2008 36 50% born during first 3 months of the year 4 17% born during last 3 months of the year Carling et al., 2009; Gil et al., 2007; Gravina et al., 2008; Auguste et Lames, 2011; Helsen et al., 2005; Williams, 2010 RAE significant for all age groups in French soccer teams (U7 to U18) Delorme et al., 2010 RAE not obvious at low level of practice Cobley et al., 2009
Aims Influence of a 6 week specific training program targeting speed and power in U15 soccer players Influence of birth month on speed and power capacities
Population 24 young soccer players Born in 1999 and 2000 (U15) Part of regional selection Played at regional or national level U14 (n = 11) U15 (n = 14) Total (n = 25) Body mass (Kg) Height (cm) 46.4 ±6.4 160.6 ±9.7 51.11 ±9.2 165.66 ±7.4 49.2 ±8.4 163.5 ±8.6 Trained daily + weekend game
Running speed assessment 20 m sprints 3 pairs of photocells 10 m apart 20 m End Standing start, run the distance as fast as possible 10 m 0 10 m time 10 20 m time Acceleration Maximal speed 0 m Start
Power assessment Vertical jump tests 1 pair of 1 m rails Counter Movement Jump (CMJ) Hands on hips Knee flexion until 90 Jump as high as possible Squat Jump (SJ) Hands on hips Start at 90 of knee flexion Jump as high as possible Flight time Jump height ht
Margaria Kalamen test Power assessment 2 pairs of photocells 9 e 6 e D Climb steps as fast as possible 3 e Step on 3 rd, 6 th et 9 th steps only Time Power P = (m x D) x g / t
Experimental design and data analysis Warm up Margaria Vertical jumps 20 m sprints CMJ, SJ, Margaria Best of the 3 trials il 0 10 m and 10 20 m times Best of the 4 trials il
Speed and power training 2 specific training sessions of 30 minutes per week during 6 weeks Sprinting drills with and without changes in direction, shuttle exercises, jumps, stair climbing
Months of birth Using quartiles Q1 Q2 Q3 Q4 U14 5 4 1 1 U15 4 3 4 2 Total 9 7 5 3 Q1 = January, February, March Q2 = April, May, June Q3 = July, August, September Q4 = October, November, December 38 % 29 % 21 % 13 % Q4 Q3 Q1 Q4 Q3 25% 26% Q2 Q2 Q1 24% 24% Majority of players born early in the year Not representative ese e of normal birth statistics Auguste et Lames, 2011; Williams, 2010 INSEE, 2011
Running speed Q1 Q2 Q3 Q4 PRE POST 0 10 m, 10 20 m and 0 20 m times 3.8 3.7 3.6 0 20 m Time (s) 22 2.2 0 10 m 2.0 1.8 Time (s) 3.5 3.4 3.3 1.6 Q1 Q2 Q3 Q4 1.6 10 20 0 m 3.2 3.1 3.0 +1.7% +0.1% +1.0% +0.7% Q1 Q2 Q3 Q4 Players born earlier are faster Time (s) 1.5 1.4 1.3 1.2 Q1 Q2 Q3 Q4 No significant training effect (+0.9% on average) Gil et al., 2013; Carling et al., 2009
Power Q1 Q2 Q3 Q4 PRE POST Margaria Kalamen test 1200 1100 1000 Power (W) 900 800 700 600 +5.0% +2.8% +10.7% +0.8% Q1 Q2 Q3 Q4 Players born at the end of the year produce less power No significant training effect (+4.8% on average)
Power Q1 Q2 Q3 Q4 PRE POST Vertical jump heights 45 CMJ 40 SJ 40 35 35 30 Height (cm) 30 25 Height (cm) 25 20 20 15 15 +7.5% +5.6% 3.7% +6.1% +0.7% +0.3% 1% +1.9% 10 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 RAE influence is lower No significant training effect (+3.9% for CMJ, +0.5% for SJ on average)
Conclusion Majority of selected players born earlier in the year As observed din the literature Players born earlier get better results except for vertical jumps Auguste and Lames, 2011 Expected, probably due to longer growth and/or training period Vertical jumps less influenced by the RAE could represent an interesting way to compare young soccer players lower limb power capacities Gil et al., 2013; Carling et al., 2009 6 week training program had no significant influence on speed and power Highly trained population, 6 weeks of training, twice a week is not sufficient to significantly improve these capacities Playing soccer naturally develops speed and power, to increase these capacities more specific work is required
: influence of birth month and effect of specific training S. Boyas, T. Hervéou, A. Rahmani, S. Durand Laboratory «Movement, Interactions, Performance» EA 4334 School of Sports Sciences, University of Le Mans InternationalCongress of Sciences and Football Valenciennes March 1 4, 2016 www.mip.univ-nantes.fr Sebastien.Boyas@univ lemans.fr