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Successful coaches of young footballplayers have an understanding of thephysical demands of the game and areable to adopt a variety of practice andgame play activities to suit different agesand stages of development. Guidelinesfor the development of young footballplayers are available in most nations.These guidelines promote the principlethat the number of players and the size ofthe pitch increase with age and stage of

development. In North America, matchesin the under-8 year old age group are splitinto 4 x 12-minute quarters, progress inmatch duration is then made withincreasing age. By 10 years of age playersparticipate in 25-minute halves, increasingto 30-minute halves by age 12 years and45-minute halves by age 19 years.

There is a tacit need to adjust juniorfootball games to match childrens stagesof growth and development. However,are these game adaptations appropriate

in terms of the physical work expected ofyoung football players? Supportingscientific research into this aspect of thegame is very limited. Only a few studies

have demonstrated that adjustments inpitch size and number of players placesufficient and appropriate physiologicaldemands on youngsters. At adult and

junior levels, the physiological demandsof football depend on factors such aspositional role, tactics and strategies,level of performance and playingapproach used by the team. Youthfootball involves multiples of shortsprints, slow jogging, walking, jumping,

tackling, kicking and changing direction.Fast recovery from work applied tomaintaining or regaining possession isessential if high intensity movementduring match-play is to be sustained.These exercise bouts place significantdemands on the energy systems ofyoung players.

THE DEMANDS OF THE GAME

One of the few studies on the demands ofpre-pubertal football used heart rate

monitoring to estimate physiologicalstress during game play. In an attempt tomeasure the cardiorespiratory strain ofyouth football, Drust and Reilly (1997)

monitored the heart rates of 11 boysand 7 girls aged 10 years who had beenplaying football for 5 years. Mean heartrates recorded after playing a 10-minutegame were 17018 and 16720beatsmin-1 for boys and girlsrespectively. Klimt (1992) reported similarheart rates of 160-180 beatsmin-1 inGerman 11 and 12 year-old players.Furthermore, heart rates increased by afurther 10 beats after playing an 8-a-side

game on a 60 x 40 metre pitch during asecond playing period of 10 minutes.These two scientific investigationssuggest that adapted football stimulateshigh cardiorespiratory responses.Moreover, heart rate ranges of 35beatsmin-1 reflect the intermittent natureof the game as illustrated in Figure 1.Klimt (1992) also reported mean bloodlactates of 3-4 mmoll-1 during game play,supporting the view that children have alimited anaerobic capacity. Felci andcolleagues (1995) revealed that the

exercise intensity when children playfootball was below the anaerobicthreshold and that youth football washighly aerobic in nature.

The PhysiologicalDemands ofJunior Football

GARETH STRATTON

09INSIGHT ISSUE 3, VOLUME 7, SUMMER 2004

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HeartRate(beatsmin-1)

10 years old; English

Boys Girls Boys Girls Boys

11-12

years old;

German

210

200

190

180

170

160

150

10 years old; English boys

10 years old; English girls

10 years old; English boys

10 years old; English girls

11-12 years old; German boys

In the adult game the demands vary byposition. In a study on youth footballers,Felci and colleagues (1995) found thatheart rate and oxygen uptake (VO2)diverged and varied according toposition. Heart rates are more closelyrelated toVO2 in midfielders thanforwards and defenders. This differencewas attributed to the more continuousnature of midfielders running duringmatch play.

Motion analysis of elite adult football hasrevealed that players run distancesbetween 8 and 13 km at about 70-80 percent ofVO2max during a game. Theexercise is intermittent and varies inintensity from walking, to sprinting,

jumping to passing, and tackling toheading and shooting. Players are incontact with the ball for roughly 180seconds, turning about 400 times duringthe game. Comparative data from matchplay in different age groups are not

available on an exstensive basis. Taskanalysis of 12 junior teams demonstratedthat individual players made an average of29 passes, received 34 passes, dribbled 5

times, made two shots on goal andattempted 20 interceptions. Losers wereless successful than winners on all actioncategories, with particularly largedifferences for dribbling and shots ongoal (Luhtanen, 1994). Data has alsobeen reported on 106, 16-18 year oldplayers from First Division clubs. Gameplaying time ranged from 57 to 74 min.Boys and girls engaged in 34 and 33offensive manoeuvres, respectively. Boys

also engaged in 21 defensive manoeuvrescompared to an average of 24 in girls.Game understanding was better for theboys compared to the girls althoughmovement in match-play was similar.

CONCLUSION

The limited research on the matchplay requirements of youth footballreveal broadly similar demands tothose reported for adults. In effectthe reduced pitch dimensions,game duration and numbers of playersper team seem developmentallyappropriate for young players.However, more detailed research

using various notational andphysiological methods is requiredbefore the precise demands of adaptedyouth football practice and game playcan be better understood.

Dr. Gareth Stratton is a Reader in Paediatric Exercise Science at Liverpool John Moores

University. He has acted as consultant to a number of childrens fitness projects and has

published in areas related to childrens exercise, health and sports performance.

Further Reading

Klimt, F., Betz, M. and Seitz, V. (1992) Metabolism and circulation of children playing soccer: In Children and ExerciseXVI: Paediatric Work Physiology (eds J. Coudert and E. Van Praagh). Masson, Paris, pp 127-29.

Drust B., and Reilly, T. (1997) Heart rate responses of children during soccer play. Science and Football III (T. Reilly,J. Bangsbo, & M. Hughes Eds.) E&FN Spon.pp 196-200.

Figure 1 Heart Rates of Junior Age Boys and Girls during Game-Play

10 INSIGHT ISSUE 3, VOLUME 7, SUMMER 2004