Effects of aerobic training on the exercise-induced decline in short-passing ability in junior soccer players Franco M. Impellizzeri, Ermanno Rampinini, Nicola A. Maffiuletti, Carlo Castagna, Mario Bizzini, and Ulrik Wisløff Abstract: To examine the effects of aerobic interval training on the decline in short-passing ability caused by a short bout of high-intensity intermittent activities. For this randomized controlled trial, 26 junior soccer players (mean age, 17.8 ± 0.6 years; mean height, 178 ± 5 cm; mean body mass, 74.5 ± 6.9 kg) were recruited. After baseline measurements, sub- jects were randomly allocated to 1 of 2 groups: the control group (CG) or the aerobic interval training group (ITG). The ITG completed 4 weeks of high-intensity aerobic training, consisting of 4 bouts of running for 4 min at 90%–95% of maximal heart rate, with 3 min of active recovery between sets, in addition to normal training. Maximum oxygen uptake, Yo-Yo Intermittent Recovery Test level 1 (YYIRT), and short-passing ability (measured using the Loughborough Soccer Passing Test (LSPT)) were measured before and after a 5 min high-intensity simulation (HIS), reproducing the most in- tense phase of a match. The ITG (n = 11), but not the CG (n = 10), showed a significant 12% and 4% increase in YYIRT and maximal oxygen consumption after training, respectively, and reduced the worsening in LSPT penalty time after the HIS (p < 0.05). The relative exercise intensity during HIS decreased in the ITG only (p < 0.01). Our results demonstrated that junior soccer players may benefit from aerobic training to attenuate the decline in short-passing ability caused by a short bout of intermittent activities completed at the same pretraining workload. Key words: soccer, technical skills, randomized controlled trial, simulation, intermittent activity, interval training. Re ´sume ´: Le but de cette e ´tude est d’analyser l’effet de l’entraı ˆnement ae ´robie par intervalle sur la diminution de l’ap- titude a ` faire de courtes passes cause ´e par une bre `ve se ´ance d’activite ´s intermittentes de forte intensite ´. Vingt-six joueurs de soccer de la cate ´gorie junior (a ˆge, 17,8 ± 0,6 ans; taille, 178 ± 5 cm; masse corporelle, 74,5 ± 6,9 kg) participent a ` cet essai ale ´atoire contro ˆle ´. Apre `s l’enregistrement des mesures de re ´fe ´rence, les sujets sont re ´partis au hasard dans deux grou- pes : un groupe de contro ˆle (CG) et un groupe a ` l’entraı ˆnement ae ´robie par intervalle (ITG). En plus de l’entraı ˆnement re ´- gulier, le groupe ITG participe a ` un programme d’entraı ˆnement ae ´robie par intervalle d’une dure ´e de 4 semaines consistant en 4 se ´ances de course d’une dure ´e de 4 minutes re ´alise ´es a ` 90–95 % de la fre ´quence cardiaque maximale, les se ´ances e ´tant entrecoupe ´es de repos actif d’une dure ´e de 3 minutes. Avant et apre `s ce programme d’entraı ˆnement, on e ´va- lue les variables suivantes : la consommation maximale d’oxyge `ne, la performance au test yo-yo, niveau 1, incluant des pe ´riodes de re ´cupe ´ration (YYIRT) et l’aptitude a ` faire de courtes passes (test des passes au soccer de Loughborough, LSPT); ces donne ´es sont prises avant et apre `s une se ´ance de simulation de forte intensite ´ (HIS) d’une dure ´e de 5 minutes reproduisant ainsi la phase la plus intense d’un match. Contrairement au groupe CG (n = 10), le groupe ITG (n = 11) ame ´- liore de 12 % et de 4 % respectivement sa performance au YYIRT et a ` l’e ´preuve du consommation maximale d’oxyge `ne et diminue la perte de temps due aux pe ´nalite ´s distribue ´es dans le LSPT effectue ´ apre `s la se ´ance de HIS (p < 0,05). On observe uniquement dans le groupe ITG une baisse de l’intensite ´ relative durant la se ´ance de HIS (p < 0,01). D’apre `s nos observations, les joueurs de soccer de niveau junior be ´ne ´ficient d’un programme d’entraı ˆnement ae ´robie, car ils perdent moins d’aptitudes a ` faire de courtes passes a ` la suite d’efforts intermittents de courte dure ´e re ´alise ´s a ` la me ˆme intensite ´ qu’avant le de ´but du programme d’entraı ˆnement. Mots-cle ´s : soccer, habilete ´s techniques, essai ale ´atoire contro ˆle ´, simulation, activite ´ intermittente, entraı ˆnement par intervalle. [Traduit par la Re ´daction] Received 2 March 2008. Accepted 14 August 2008. Published on the NRC Research Press Web site at apnm.nrc.ca on 3 December 2008. F.M. Impellizzeri 1 and N.A. Maffiuletti. Neuromuscular Research Laboratory, Schulthess Clinic, Zurich, Switzerland. E. Rampinini. Human Performance Laboratory, Mapei Sport Research Center, Castellanza (VA), Italy. C. Castagna. School of Sport and Exercise Sciences, Faculty of Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy. M. Bizzini. Neuromuscular Research Laboratory, Schulthess Clinic, Zurich, Switzerland; FIFA Medical Assessment and Research Centre, Zurich, Switzerland. U. Wisløff. Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Faculty of Medicine, Trondheim, Norway. 1 Corresponding author (e-mail: franco.impellizzeri@kws.ch). 1192 Appl. Physiol. Nutr. Metab. 33: 1192–1198 (2008) doi:10.1139/H08-111 # 2008 NRC Canada