Metabolic Profile of Football Athletes During Running Incorporating Different Levels of Direction Change

Abstract

We evaluated the metabolic profile of football athletes during running incorporating different levels of direction change. A total of 34 male football athletes performed a running test in the laboratory and two running tests in a gymnasium. The laboratory running test (0-TURN) included continuous forward running and was performed on a motorized treadmill. The two running tests conducted in the gymnasium involved repetitive bouts of continuous running for 20 m followed by directional changes of either 90° (90-TURN test) or 180°(180-TURN test). Repeated-measures analysis of variance comparing results in the three running tests revealed statistically significant main effects in maximal oxygen uptake (VO2max), blood lactate concentration, and maximum heart
rate (p<0.05) but not in maximal accumulated oxygen deficit (p>0.05). Post hoc t tests incorporating a Bonferroni correction revealed that the VO2max was similar in the 0-TURN and the 90-TURN tests (p>0.05). However, statistically significant differences in VO2max were observed between the 0-TURN and the 180-TURN tests as well as between the 90-TURN and the 180-TURN tests (p<0.001). The lowest values of blood lactate concentration were measured after the 90-TURN test, while the highest were recorded following the 180-TURN test (p<0.001). Finally, the maximum heart rate was similar in the 0-TURN and the 90-TURN tests (p>0.05), but it was significantly augmented in the 180-TURN tests (p<0.05).Based on the present results, we conclude that increasing the
angle of direction change from 0°, to 90°, and, finally, to 180° during intermittent running in football athletes results in significantly increased metabolic demands.