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]

Association of short-passing ability with athletic performances in youth soccer players

This study was designed to examine the relationship between multiple short-passing ability [measured using the Loughborough Soccer Passing Test [LSPT]] and athletic performances in youth soccer players. Forty-two young soccer players [age 14.8 +/- 0.4years] performed the LSPT, the squat-jump [SqJ], the counter movement jump [CMJ], the 30m sprints [with 5m and 20m split times also recorded], the 15m agility run [Agility-15m], the 15m ball dribbling [Ball-15m], the Illinois agility test [IAGT] and the Yo-Yo IRT Level 1 tests. LSPT total performance [LSPT TP] showed significant positive correlation with 5m, 20m, and 30m sprint times, Agility-15m, Ball-15m and Illinois agility test [r=0.60, r=0.58, r=0.49, r=0.75, r=0.71 and r=0.72; P<0.01, respectively]. Significant negative correlation were found between LSPT TP and SqJ and CMJ [r=?0.62 and r=?0.64; P<0.01, respectively]. It was determined that Agility-15m, Illinois agility test and Ball-15m were the most effective factors associated with LSPT TP among other factors in multiple regression analysis. This study showed that LSPT TP of young elite soccer players is determined by their agility abilities, thus enabling this test to be used for talent identification purposes

effects of music on high-intensity short-term exercise in well trained athletes

The purpose of this investigation was to assess the effects of listening to music during warm-up on short-term supramaximal performances during the 30-s Wingate test in highly trained athletes. Twelve young male athletes [20.6 +/- 1.8 yrs, 177 +/- 4.4 cm and 72.3 +/- 5.3 kg] underwent two Wingate tests in separate sessions with a recovery period of 48 h in-between, either after a 10 min of warm-up with [MWU] or without [NMWU] music. High tempo music [> 120 to 140bpm] was selected for the study. Heart rate [HR] and rate of perceived exertion [RPE] were recorded after the warm-up [for HR = average of warm-up] and immediately after the Wingate test. HR, RPE and the fatigue index during the Wingate test are not affected by the incorporation of music during warm-up. However, power output [P[peak] and P[mean]] was significantly higher after MWU than NMWU [p < 0.05]. The relative increases were 4.1 +/- 3.6 and 4.0 +/- 3.7 W·kg[-1] for P[peak] and P[mean] respectively. These findings demonstrated the beneficial effect of music during warm-up on short-term supramaximal performances. As it's a legal method and an additional aid, music may be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions during short-term supramaximal exercises

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

Diurnal variations in physical performances related to football in young soccer players

This study investigated the effects of time-of-day on aerobic and anaerobic performances during the Yo-Yo, repeated sprint ability [RSA] and the Wingate tests in young soccer players. In a counterbalanced and a random order, twenty junior male soccer players completed the Yo-Yo, the RSA, and the Wingate tests at two different times-of-day: 07:00 and 17:00 h. During the Yo-Yo test, the total distance [TD] covered and the estimated maximal aerobic velocity [MAV] were determined. The peak power [PP] during each sprint, the percentage of decrement of PP [PD] and total work [Wtotal] during the RSA test were, also, measured. In addition, during the Wingate test, the peak [P[peak]] and mean [P[mean]] powers were recorded. During the Wingate test, P[peak] and P[mean] were significantly higher at 17:00 than 07:00 h [P<0.05] with diurnal gains of 3.1 +/- 3.6 and 2.9 +/- 3.5% respectively. During the RSA test, PP during the first two sprints, Pdec and Wtotal were, also, higher in the evening [P<0.05] with amplitudes of 4.8 +/- 4.6, 3.1 +/- 3.0, 13.1 +/- 32.1, and 4.1 +/- 2.5% respectively. Likewise, TD and MAV during the Yo-Yo test were higher at 17:00 than 07:00 h with diurnal gains of 13.1 +/- 10.7 and 4.2 +/- 3.3 respectively. The present study confirms the daily variations of both aerobic and anaerobic performances during the Yo-Yo, the RSA, and the Wingate tests in trained young Tunisian soccer players

Monitoring training load and fatigue in rugby sevens players

Trainers and physical fitness coaches' need a useful tool to assess training loads to avoid overtraining. However, perceived scales or questionnaires were required. Therefore, the purpose of this study was to assess whether a short 8-item questionnaire of fatigue could be a useful tool for monitoring changes in perceived training load and strain among elite rugby Sevens [7s] players during preparation for a major competition. Sixteen elite rugby 7s players completed an 8-week training program composed of 6-week intense training [IT] and 2-week reduced training [RT]. They were tested before [T0], after the IT [T1] and after the RT [T2]. The quantification of the perceived training load and strain were performed by the session-RPE [rating of perceived exertion] method and concomitantly the 8-item questionnaire of fatigue was administered. Training load [TL] and strain [TS] and total score of fatigue [TSF from the 8-item questionnaire] increased during IT and decreased during RT. Simultaneously, physical performances decreased during IT and were improved after LT. The changes in TL, TS and TSF correlated significantly over the training period [r=0.63-0.83]. These findings suggest that the short questionnaire of fatigue could be a practical and a sensitive tool for monitoring changes in training load and strain in team-sport athletes. Accordingly, the simultaneous use of the short questionnaire of fatigue along with the session-RPE method for perceived changes in training load and strain during training could provide additional information on the athletes' status, allowing coaches to prevent eventual states of overreaching or overtraining

effect of Ramadan fasting on physical performances, mood state and perceived exertion in young footballers

This study was designed to assess the effects of Ramadan fasting on the profile of mood state and perceived exertion in young soccer players and aerobic and anaerobic performances during the Yo-Yo, repeated sprint ability [RSA] and the Wingate tests. Twenty junior male soccer players completed the Yo-Yo, the RSA, and the Wingate tests on three different occasions: one-week before Ramadan [BR], the second week [SWR] and the fourth week [ER] of Ramadan. The total distance [TD] covered and the estimated maximal aerobic velocity [MAV] during the Yo-Yo test were recorded. During the RSA test, peak power [PP] during each sprint, the percentage of decrement of PP [PD] and total work [Wtotal] were calculated. During the Wingate test, peak [Ppeak] and mean [Pmean] powers and fatigue index [FI] were recorded. TD and MAV [P=0.01] during the Yo-Yo test and PP [P=0.01, P=0.004, P=0.001, P=0.01, P=0.03 for sprints 1, 2, 3, 4, and 5, respectively] and Wtotal [P=0.02] during the RSA test were significantly higher during BR than ER. Furthermore, muscle fatigue during the RSA test increased significantly from BR to ER [P=0.01]. Ppeak and Pmean during the Wingate test decreased significantly from BR to SWR and ER [P<0.0005]. FI was higher during SWR [P=0.001] and ER [P<0.0005] than BR. In addition, rating of perceived exertion scores and fatigue estimated by the profile of mood state questionnaire were higher during Ramadan in comparison with BR. The present study suggests that both aerobic and anaerobic performances during the Yo-Yo, the RSA and the Wingate tests were affected by Ramadan fasting in young soccer players