Physiological Status and Prediction of Cardiovascular Fitness in Highly Trained Youth Soccer Athletes

Abstract

This study evaluated the physiological status and assessed the validity of the 20-m shuttle run test (20 MST) in pre- dicting VO2 max values of these same athletes. Thirteen high- ly trained male soccer players (age 12.62 6 0.65 years) were tested for VO2 max, heart rate max, and maximum lactate via direct laboratory measurement (i.e., maximal treadmill test (TM)) and the 20 MST. Based on two 20 MST prediction equations, the cross-validation statistics were r 5 0.78, SE 3.82 for equation 1 and r 5 0.86, SE 52 1.39 for equation 2. No significant differences were found between the observed and predicted VO2 max values (p . 0.05). Specifically, the directly measured VO2 max 5 56.53 6 5.80, with predicted values of 58.68 6 3.22 and 55.14 6 3.89 for equations 1 and 2, respectively. There was a small but significant (p # 0.05) difference in HR max between the test protocols, with no significant difference for lactate values (TM lactate 5 6.07 6 1.40 and 20 MST lactate 5 6.26 6 1.92 mm/L). In conclusion, the 20 MST appears to be a valid method for predicting the cardiovascular fitness of youth soccer athletes.