Biochemical responses to level-1 Yo-Yo intermittent recovery test in young Tunisian football players

The aim of this work was to investigate the metabolic and muscle damage responses after the level-1 Yo-Yo intermittent recovery test [YYIRT] in young football players. Fifteen male football players [17.42 +/- 0.2 yrs, 69.91 +/- 4.4 kg, 178.64 +/- 3.8 cm; mean +/- SD] participated in this study. Fasting blood samples for various biochemical parameters [i.e. lactate [Lac], glucose [GLC], triglycerides [Tri], creatine kinase [CK], uric acid [UA]] collected from a forearm vein after 5-min of seated rest and 3-min after the test. Moreover, rating of perceived exertion [RPE] and maximal heart rate during and after the YYIRT were recorded. Mean levels of the selected biochemical markers were raised after the YYIRT exercise [P<0.001 for the other markers]. Moreover, lipid parameters increased significantly after the test [P<0.01 for Tri and P<0.001 for HDL]. These findings confirm the higher metabolic demand of aerobic as well as anaerobic metabolism and reflect a significant mobilization of purine cycle during the YYIRT. The increase of muscle damage markers also reflects the higher anaerobic solicitation. From these findings, we can conclude the importance of aerobic and anaerobic metabolism during soccer-specific endurance performance [i.e. YYIRT, soccer match]

Effect of short-term maximal exercise on biochemical markers of muscle damage, total antioxidant status, and homocysteine levels in football players

Prolonged physical exercise results in transient elevations of biochemical markers of muscular damage. This study examined the effect of short-term maximal exercise on these markers, homocysteine levels [Hcy], and total antioxidant status [TAS] in trained subjects. Eighteen male football players participated in this study. Blood samples were collected 5-min before and 3-min after a 30-s Wingate test. The results indicated that plasma biochemical markers of muscle injury increased significantly after the Wingate test [P<0.05]. Moreover, significant increase of white blood Cells and their main subpopulations [i.e. monocytes, neutrophiles, and lymphocytes] [P<0.001] has been observed. Likewise, uric acid, total bilirubin, and TAS increased significantly after exercise [P<0.05]. However, Hcy levels were unaffected by the Wingate test [for 3-min post-exercise measurement]. Short-term maximal exercise [e.g. 30-s Wingate test] is of sufficient intensity and duration to increase markers of muscle damage, and TAS; but not Hcy levels. Increases in the selected enzymes probably come primarily from muscle damage, rather than liver damage. Moreover, increase of TAS confirms the Wingate test induced oxidative stress