Anne Delextrat

Heart rate, blood lactate concentration, and time–motion analysis of female basketball players during competition

Abstract The aim of this study was to examine the physiological demands and movement patterns of female basketball players after changes in the rules of the game. Nine varsity players were studied during nine official games. Each game was videotaped to identify the frequencies of the main movements performed, heart rate was recorded continuously, and blood samples were collected to determine blood lactate concentration when the competition rules allowed. The main results showed that the players performed on average 652 ± 128 movements per game, which corresponded to a change in activity every 2.82 s. Mean heart rate was 165 ± 9 beats · min−1 (89.1% of maximum heart rate) for total time and 170 ± 8 beats · min−1 (92.5% of maximum) for live time. Mean blood lactate concentration was 5.2 ± 2.7 mmol · l−1 (55.9% of maximum blood lactate concentration). In addition, heart rates were significantly higher in the first half than the second half of games. These results indicate: (1) a greater physiological load compared with previous studies on female players tested before the rules modification (Beam & Merrill, 1994; McArdle et al., 1971) and (2) lower movement frequencies compared with male players competing under modern rules (Ben Abdelkrim et al., 2007). These observations must be taken into account by coaches and conditioning specialists working with female players.

Physiological Testing of Basketball Players: Toward a Standard Evaluation of Anaerobic Fitness

Delextrat, A and Cohen, D. Physiological testing of basketball players: toward a standard evaluation of anaerobic fitness. J Strength Cond Res 00: 1-7, 2008-The aim of this study was to examine whether the changes in the rules of the game instituted in 2000 have modified the physiological factors of success in basketball. The performances of 8 elite male players and 8 average-level players were compared in order to identify which components of fitness among agility, speed, anaerobic power, anaerobic capacity, and upper body strength were key determinants of performance in modern basketball. Each subject performed 7 tests, including vertical jump (VJ), 20-m sprint, agility T test, suicide sprint, 30-second Wingate anaerobic test (WAnT), isokinetic testing of the knee extensors, and 1 repetition maximum (1RM) bench press test. The statistical difference in the anaerobic performances was assessed by Students t test. The main results showed that, compared to average-level players, elite-level players achieved significantly better performances in the agility T test (+6.2%), VJ test (+8.8%), peak torques developed by knee extensors (+20.2%), and 1RM bench press (+18.6%, p < 0.05). In contrast, no significant difference between groups was observed on 20-m sprint, suicide run, and parameters of the WAnT (p > 0.05). These results emphasized the importance of anaerobic power in modern basketball, whereas anaerobic capacity does not seem to be a key aspect to consider. In this context, coaches are advised to avoid using exercises lasting ≥30 seconds in their physical fitness programs, but instead to focus on short and intense tests such as VJ, agility T test, and sprints over very short distances (5 or 10 m).

Ten-year secular changes in muscular fitness in English children

1.Faculty of Life Sciences, London Metropolitan University, London, UK2.Department of Biological Sciences, University of Essex, Colchester, UK3.Centre for Research in Human Development, Concordia University, Montreal, QC, CanadaCorrespondenceDD Cohen, Faculty of Life Sciences, London Metro-politan University, London, UK.Tel: +44 207 133 4687 |Fax: +44 0207 133 4149 |Email: d.cohen@londonmet.ac.ukReceived8 October 2010; revised 25 February 2011;accepted 8 April 2011.DOI:10.1111/j.1651-2227.2011.02318.x

Strength, Power, Speed, and Agility of Women Basketball Players According to Playing Position

Delextrat, A and Cohen, D. Strength, power, speed, and agility of women basketball players according to playing position. J Strength Cond Res 23(7): 1974-1981, 2009-The aim of the present study was to investigate the effect of playing position on strength, power, speed, and agility performances of women basketball players. Thirty subjects playing at national level participated in this study. They were divided into 3 groups according to playing position: guards (positions 1 and 2), forwards (positions 3 and 4), and centers (position 5). Each subject performed 8 tests presented in a random order: The 30-second Wingate Anaerobic test (WAnT), isokinetic testing of the knee extensors, 2 types of jump tests, a 20-m sprint, the agility T-test, a suicide run, and a basketball chest pass. Statistical differences between playing positions were assessed using a 1-way analysis of variance (ANOVA) and Scheffe post hoc analyses. Results showed that guards performed significantly better than centers for the relative peak and mean power achieved during the WAnT (+13% and +16.9%, respectively), relative peak torque of knee extensors (+19.5%), single-leg jump (+21.8), suicide run (+7.5%), and agility T-test (+6.4%, p < 0.05). In addition, guards achieved significantly better performances than forwards in the suicide run test (+7.1%) and forwards were characterized by a greater peak torque of the knee extensors compared to centers (+22.1%). These results indicate that specific fitness training must be undertaken according to playing position. The ability to perform the suicide run, the single-leg jump, and the different movements involved in the agility T-test must be developed in guards. In contrast, speed over short distances and strength development of lower body and upper body should be performed by all playing positions.

Handgrip strength in English schoolchildren

Aims:  The aims of this study were to evaluate patterns of handgrip (HG) strength in relation to gender and age in English schoolchildren and to compare this with existing data and produce reference data for this population.

Drafting during swimming improves efficiency during subsequent cycling.

PURPOSE The aim of the present study was to investigate the effects of drafting (i.e., swimming directly behind a competitor) while swimming with a wet suit on physiological parameters and cadence during subsequent cycling. METHODS Eight well-trained male triathletes underwent two submaximal sessions conducted in a counterbalanced order. One of these sessions (SAC) consisted of a 750-m swim, performed at competition pace, followed by a 15-min ride on a bicycle ergometer at 75% of maximal aerobic power and at a freely chosen cadence. During the other session (SDC) the subjects swam 750 m in a drafting position at the same pace as during SAC and then performed the 15-min cycling test at the same intensity as during SAC. RESULTS The main result indicated that cycling efficiency was significantly improved when the cycling session was preceded by a swimming bout performed in drafting position compared with an isolated swimming bout (+4.8%, P < 0.05). CONCLUSION These results could be partly explained by the lower relative intensity observed during swimming in the SDC trial when compared with the SAC trial. This study suggests the relative importance of swimming condition and highlights the advantage of drafting during the swimming portion of a sprint triathlon.

Effects of sports massage and intermittent cold-water immersion on recovery from matches by basketball players

Abstract The aim of this study was to compare the effects of intermittent cold-water immersion and massage on perceptual and performance markers of recovery by basketball players after competitive matches. Eight men (age 23 ± 3 years; stature 190.5 ± 8.9 cm; body mass 90.3 ± 9.6 kg; body fat 12.8 ± 4.8%) and eight women (age 22 ± 2 years; stature 179.0 ± 8.5 cm; body mass 77.6 ± 9.2 kg; body fat 22.5 ± 6.6%) basketball players participated. Massage, cold-water immersion or control were applied immediately after competitive matches, followed by assessments of perceptual measures of recovery and physical performance, countermovement jump and repeated-sprint ability 24 h after intervention. There was lower perception of fatigue overall and in the legs immediately after the massage and cold-water immersion condition (P < 0.001; = 0.91). Furthermore, women had a lower perception of fatigue in cold-water immersion than massage at any testing time (P < 0.001; = 0.37). Jump performance was greater after cold-water immersion than the control condition (P = 0.037, = 0.37). There was no effect of any of the recovery interventions on repeated-sprint measures (P at best 0.067, at best 0.68). The results suggest that both massage and cold-water immersion improve perceptual measures of recovery. Furthermore, cold-water immersion improves jump performance although neither such immersion nor massage had an effect on repeated-sprint ability. This suggests that, overall, cold-water immersion is more useful than massage in the recovery from basketball matches, especially in women.

Small-Sided Game Training Improves Aerobic Capacity and Technical Skills in Basketball Players

The aim of this study was to compare the effects of 2 training interventions based on small-sided games (SGG) and high-intensity interval training (HIT) on physical and technical performance of male junior basketball players. A secondary objective was to investigate if these effects were similar in starting and bench players. 18 players participated in a pre-testing session, 6-weeks intervention period and a post-testing session. Pre- and post-sessions involved assessments of aerobic fitness, repeated sprint ability (RSA), defensive and offensive agility, upper and lower body power, shooting and passing skills. Mixed-design analysis of variance (ANOVA) with Bonferroni corrected pairwise comparisons examined the effects of time and type of intervention on physical and technical performances. The main results showed that both interventions resulted in similar improvements in aerobic capacity (+3.4% vs. +4.1%), with greater improvements in bench players compared to starting players (+7.1% vs. +1.1%, P<0.05). However, RSA was unchanged after both interventions. In addition, compared to HIT, SSG resulted in greater improvements in defensive agility (+4.5% vs. -2.7%, P<0.05), shooting skills (+7.4% vs. -2.4%, P<0.05) and upper body power (+7.9% vs. -2.0%, P<0.05). These results suggest that SSG should be prioritized in physical conditioning of junior basketball players during the season. However, when RSA is targeted, more specific training seems necessary.

Effect of a simulated soccer match on the functional hamstrings-to-quadriceps ratio in amateur female players

The purpose of this study was to investigate the effect of a simulated soccer test on the functional hamstrings‐to‐quadriceps ratio (Hecc : Qcon) in female soccer players. Fourteen amateur players (age, 26.1 ± 4.6 years; height, 168 ± 12 cm; body mass, 62.7 ± 5.5 kg; body fat, 23.7 ± 2.2%) performed the modified Loughborough Intermittent Shuttle Test (modified LIST). Isokinetic strength assessments of the hamstrings and quadriceps on the dominant and non‐dominant legs at 120°/s were performed before and immediately after the modified LIST. Hecc : Qcon was calculated as the ratio of the peak eccentric torque of the hamstrings to the peak concentric torque of the quadriceps. A two‐way univariate analysis of variance was used to assess the effect of time and leg dominance on Hecc : Qcon. The main results showed that the modified LIST led to a significant decrease in Hecc : Qcon in the dominant (−14.1%) and non‐dominant legs (−8.0%) (P = 0.02). However, this decrease was not significantly different between dominant and non‐dominant legs (P = 0.42). These results reflect a greater risk of hamstrings tears and ACL sprains at the end of soccer matches.

Angle-Specific Eccentric Hamstring Fatigue After Simulated Soccer

PURPOSE To evaluate the effect of simulated soccer on the hamstrings eccentric torque-angle profile and angle of peak torque (APTeccH), and on the hamstrings:quadriceps torque ratio at specific joint angles (ASHecc:Qcon). METHODS The authors assessed dominant-limb isokinetic concentric and eccentric knee flexion and concentric knee extension at 120°/s in 9 semiprofessional male soccer players immediately before and after they completed the Loughborough Intermittent Shuttle Test (LIST). RESULTS The LIST resulted in significant decreases in eccentric hamstrings torque at 60°, 50°, and 10° and a significant (21.8%) decrease in ASHecc:Qcon at 10° (P < .05). APTeccH increased from 7.1° ± 1.0° to 18.8° ± 4.2° (P < .05). Eccentric hamstrings peak torque significantly declined from 185.1 ± 70.4 N·m pre-LIST to 150.9 ± 58.5 N·m post-LIST (P = .002), but there were no significant changes in hamstrings or quadriceps concentric peak torque (P = .312, .169, respectively). CONCLUSIONS Simulated soccer results in a selective loss of eccentric hamstrings torque and hamstrings-to-quadriceps muscle balance at an extended joint position and a shift in the eccentric hamstrings APT to a shorter length, changes that could increase vulnerability to hamstrings injury. These findings suggest that injury-risk screening could be improved by evaluating the eccentric hamstrings torque-angle profile and hamstrings strength-endurance and that the development of hamstrings fatigue resistance and long-length eccentric strength may reduce injury incidence.