EFFECTS OF SOCCER TRAINING ON AEROBIC AND ANAEROBIC THRESHOLDS WITH EMPHASIS ON LACTATE RECOVERY

Abstract

High blood lactic acid levels during soccer may hinder performance, by limiting individual abilities. Aerobic (AT), and anaerobic thresholds (ANT) causing 2.0 and 4.0 mM blood lactate levels respectively, are accepted as sound criteria of aerobic endurance, and are used in devising and evaluating training loads. Effective blood lactate elimination is also an important factor for high level performance. Studies on the relationships of lactate thresholds and recovery under field conditions are scarce. The present study's main objective is to determine the effect of three month's training on the AT and ANT, and to evaluate the relationships of the latter with blood lactate elimination following an incremental running exercise in premier league soccer players. Tests were performed on two occasions at the beginning and end of a three month's period in 11 of 18 soccer players (23.6 ± 4.7 yrs of age) who participated in the study. The testing protocol consisted of a 40m shuttle run test starting at 8.0 km/h, and stepwise incremented by 1.2 km/h every 5 min, until volitional fatigue, with 1 min rests in-between steps for blood sampling and heart rate (HR) determination. Lactate recovery was evaluated in all 18 players during the second test. Players were separated into active, jogging (AG) or passive, sitting (PG) recovery groups, respectively. Blood samples for lactate were obtained following 2 (LA2) and 10 min (LA10) the completion of the shuttle run test. The fall in blood lactate concentration (∆mM/min) was defined as lactate elimination (LE). At the end of the training period, AT and ANT speeds of the 11 players improved by 8.5 and 6.6% respectively (p>0.05). No significant differences were observed between the the lactate levels of the two groups at the end of the runs. LE of the AG (0.55 mM/min) was significantly (p<0.05) higher than that of the PG (0.31 mM/min), indicating that light jogging is effective in a faster and more efficient recuperation. Neither AG's nor PG’s threshold speeds displayed any correlation with their LE scores, but correlations obtained between post-testing lactate levels and these threshold speeds may suggest an indirect relationship.