Abderraouf Ben Abderrahman

Effects of Playing Surface (hard and Clay Courts) on Heart Rate and Blood Lactate During Tennis Matches Played by High-level Players

Martin, C, Thevenet, D, Zouhal, H, Mornet, Y, Delès, R, Crestel, T, Ben Abderrahman, A, and Prioux, J. Effects of playing surface (hard and clay courts) on heart rate and blood lactate during tennis matches played by high level players. J Strength Cond Res 25(1): 163-170, 2011-The aim of this study was to compare tennis matches played on clay (CL) and resin (R) courts. Six matches were played (3 on CL courts and 3 on R courts) by 6 high-level players. Heart rate (HR) was monitored continuously while running time (4.66 m), and blood lactate concentration ([La]) were measured every 4 games. Mean duration of points and effective playing time (EPT) were measured for each match. Mean HR (154 ± 12 vs. 141 ± 9 b·min−1) and [La] values (5.7 ± 1.8 vs. 3.6 ± 1.2 mmol·L−1) were significantly higher on CL (p < 0.05). The [La] increased significantly during the match on CL court. Mean duration of rallies (8.5 ± 0.2 vs. 5.9 ± 0.5 seconds) and EPT (26.2 ± 1.9 vs. 19.5 ± 2.0%) were significantly longer (p < 0.05) on CL. Running time values in speed tests were not significantly different between CL and R. Running time performance was not significantly decreased during the match, whatever the playing surface. This study shows that the court surface influences the characteristics of the match and the players physiological responses. The court surface should be a key factor for consideration when coaches determine specific training programs for high-level tennis players.

Original Research: Effect of sprint and strength training on glucoregulatory hormones: Effect of advanced age

The aim of this study was to examine the effect of high-intensity sprint and strength training (HISST) on glucoregulatory hormones in young (20 years) and middle-aged (40 years) men. Thirty-six moderately trained men participated as volunteers in this study. After medical examination, eligible subjects were randomly assigned to one of four groups according to their age: a young training group (21.3 ± 1.3 yrs, YT, n = 9), a young control group (21.4 ± 1.7 yrs, YC, n = 9), a middle-aged training group (40.7 ± 1.8 yrs, AT, n = 9), and a middle-aged control group (40.5 ± 1.8 yrs, AC, n = 9). YT and AT participated in HISST for 13 weeks. Before and after HISST, all participants performed the Wingate Anaerobic Test (WAnT). Blood samples were collected at rest, after warm-up (50% VO2max), immediately post-WAnT, and 10 min post-WAnT. Before HISST, we observed significantly higher (P < 0.05) glucose concentrations in AT (5.86 ± 0.32 mmol.L−1) compared to YT (4.24 ± 0.79 mmol.L−1) at rest, and in response to WAnT (6.56 ± 0.63 mmol.L−1 vs. 5.33 ± 0.81 mmol.L−1). Cortisol levels were significantly higher (P < 0.05) in AT than in YT in response to WAnT (468 ± 99.50 ng.mL−1 vs. 382 ± 64.34 ng.mL−1). Catecholamine levels measured at rest and in response to WAnT rose in a similar fashion. After HISST, this “age effect” disappeared at rest and in response to exercise in the trained groups (YT and AT). Changes in hormone concentrations with intense training are due to adaptive changes in various tissues, especially in the skeletal muscle and liver in trained subjects. HISST may, at least in part, counteract the negative “age effect” on glucose metabolism.

Hormonal (Cortical-Gonadotropic Axis) and Physical Changes With Two Years Intense Exercise Training in Elite Young Soccer Players

Abstract Hammami, MA, Ben Abderrahman, A, Hackney, AC, Kebsi, W, Owen, AL, Nebigh, A, Racil, G, Tabka, Z, and Zouhal, H. Hormonal (cortical-gonadotropic axis) and physical changes with two years intense exercise training in elite young soccer players. J Strength Cond Res 31(9): 2388–2397, 2017—The aim of this study was to investigate the effects of 2 soccer-training seasons on physical fitness and hormone concentrations in elite youth soccer players. Twenty male elite soccer players (SP, age 14.5 ± 0.4 years) and 20 male control subjects (CS, age 14.3 ± 0.3 years) participated in the study. Anthropometric measurements, aerobic (Yo-Yo Intermittent Recovery Test Level 1 [YYIRT1]) and anaerobic soccer relevant performances (jump and sprint tests), blood testosterone (T), cortisol (C), sex hormone binding globulin (SHBG), and T/C ratio were assessed 5 times (from T0 to T4) during 2 competitive seasons. Significant differences from basal values (&Dgr;) of T, SHBG, and C between SP and CS were observed (p < 0.01). Additionally, T and T/C ratio changes were positively correlated with physical performance (p ⩽ 0.05). In conclusion, as expected, higher T concentration and greater power performance were observed in the soccer players group compared with controls. Our findings also show that the T concentrations and power performance outcomes co-vary positively over the 2 soccer seasons in soccer players.

Drafting improves 3000m running performance in elite athletes: Is it a placebo effect?

PURPOSE: The study was designed to determine the effect of drafting on running time, physiological response and rate of perceived exertion (RPE) during 3000m-track running. METHODS: Ten elite middle and long distance runners performed three track-running sessions. The first session determined maximal oxygen uptake (VO2max) and maximal aerobic speed (MAS) using a lightweight ambulatory respiratory gas exchange system (K4B2). The second and the third tests consisted of non-drafting 3000m running (3000mND) and 3000m running with drafting for the first 2000m (3000mD) performed on the track in a randomized counter-balanced order. RESULTS: Performance during the 3000m (553.59±22.15 s) was significantly slower (p<0.05) than during the 3000mD (544.74±18.72 s). Cardiorespiratory responses were not significantly different between the trials. However, blood lactate concentration was significantly higher (p<0.05) after the 3000mND (16.4±2.3mmol.L-1) than after the 3000mD (13.2±5.6mmol.L-1). Athletes perceived the 3000mND as more strenuous than the 3000mD (p<0.05) (RPE = 16.1±0.8 vs. 13.1±1.3). Results demonstrate that drafting has a significant effect on performance in highly trained runners. CONCLUSION: This effect could not be explained by a reduced energy expenditure or cardio-respiratory effort as a result of drafting. This raises the possibility that drafting may aid running performance by both physiological and non-physiological (i.e. psychological) effects.

Drafting's Improvement of 3000-m Running Performance in Elite Athletes: Is It a Placebo Effect?

PURPOSE To determine the effect of drafting on running time, physiological response, and rating of perceived exertion (RPE) during 3000-m track running. METHODS Ten elite middle- and long-distance runners performed 3 track-running sessions. The 1st session determined maximal oxygen uptake and maximal aerobic speed using a lightweight ambulatory respiratory gas-exchange system (K4B2). The 2nd and the 3rd tests consisted of nondrafting 3000-m running (3000-mND) and 3000-m running with drafting for the 1st 2000 m (3000-mD) performed on the track in a randomized counterbalanced order. RESULTS Performance during the 3000-mND (553.59±22.15 s) was significantly slower (P<.05) than during the 3000-mD (544.74±18.72 s). Cardiorespiratory responses were not significantly different between the trials. However, blood lactate concentration was significantly higher (P<.05) after the 3000-mND (16.4±2.3 mmol/L) than after the 3000-mD (13.2±5.6 mmol/L). Athletes perceived the 3000-mND as more strenuous than the 3000-mD (P<.05) (RPE=16.1±0.8 vs 13.1±1.3). Results demonstrate that drafting has a significant effect on performance in highly trained runners. CONCLUSION This effect could not be explained by a reduced energy expenditure or cardiorespiratory effort as a result of drafting. This raises the possibility that drafting may aid running performance by both physiological and nonphysiological (ie, psychological) effects.

Laterality influences agility performance in elite soccer players

Introduction: Laterality (i.e., handedness, footedness, and eyedness) could have an impact on highly repeated soccer movements and thus, could influence performance. The purpose of this study was to examine the laterality of high-level football players and its effects on 180° left and right U-turn movements. Materials and Methods: Handedness, footedness, and eyedness were determined in 72 elite football players (EFP, 18.2 ± 2.2 years) from the Stade Rennais Football Club (French League 1) and 9 amateur football players (AFP, 19.6 ± 2.1 years). Players performed a visual-motor task on a synthetic pitch consisting of 180° left and right rotations as fast as possible in response to a visual light on a computer screen. Movement times and reactive times for each left and right rotation were recorded with an accelerometer and video display. Results: Laterality profiles showed a majority (χ2 = 9.42, df = 2, p = 0.031) of crossed formulas (i.e., dominant leg or hand is controlateral to the dominant eye) for EFP (53 ± 7%) and a majority of non-crossed formulas for AFP (63 ± 9%). Reaction times were significantly faster (p = 0.028, effect size = 0.148, trivial) in EFP right-eyed (568.2 ± 55.5 ms) than in AFP (610.0 ± 43.9 ms). For the left rotation and for right-footed players, movement times were significantly different (p = 0.043, effect size = 0.413, small) between EFP (1.15 ± 0.07 s) and AFP (1.17 ± 0.07 s). A significant difference (p < 0.033) was observed between footedness and rotation movement times in the EFP. Conclusion: Our results showed that laterality profiles differed between EFP and AFP. Hence, in EFP, reaction times depended on the side of the visual stimulus. Moreover, leg laterality of EFP influenced 180° left or right rotation speed. Our results indicate the importance of determining laterality in soccer players and identifying deficits in performance when turning.