Physiological responses of batsmen during a simulated One Day International century

Background: There is a limited amount of literature on the physiological cost of batting. Of the studies that have been completed, most have used protocols that are of short duration and high intensity, and it has been questioned whether this represents actual game play. Furthermore, it is difficult to study sports such as cricket due to the intermittent nature of the game.Objective: To determine the physiological responses of batsmen during a simulated One Day International century.Methods: Seventeen male batsmen from the Rhodes University Cricket Club performed a simulated batting work bout known as the BATEX© protocol. The protocol consisted of six, five overs stages, each lasting 21 minutes. Three of the stages (stages one, three and five) were low-intensity stages and the other three (stages two, four and six) were high-intensity stages. During the work bout selected physiological responses were recorded..Results: Heart rate (124±15-159±14 beats.min-1), oxygen uptake (29.3±6.1-43.4±6.3 ml.kg-1.min-1), energy expenditure (48.1±9.2- 109.2±10.5 kJ.min-1) and core temperature (37.7±0.3-38.7±0.4 oC) responses all increased significantly (p<0.05) between stage one and stage six. The respiratory exchange ratio decreased significantly (p<0.05) between stages one and six (0.90±0.19- 0.89±0.37).Conclusions: Batting is more physically demanding than originally thought, and as a result training programmes should concentrate on simulating real match play situations to improve performance and reduce the risk of injury.Keywords: cricket, energy expenditure, hear

Workloads of forward and backline adolescent rugby players: a pilot study

Background: There is minimal research on workloads of adolescent rugby players. Therefore, the main aim of this study was to determine the workloads placed on a cohort of South African adolescent rugby players (n = 17), during an in-season period.Methods: Session RPE ratings were collected daily, 30 minutes after the training session concluded, during an 11-week in-season period. The training load was calculated as the session ratings of perceived exertion multiplied by the session’s duration (min).Results: The main finding of the study was that the adolescents in this investigation had similar workloads to elite players but higher workloads than other studies on adolescent rugby players. The forwards (3311±939 arbitrary units; AU) had a higher workload than backline players (2851±1080 AU). There was no difference between forwards and backline players with regards to the acute:chronic workload ratio.Conclusion: Workloads are high in these adolescent players, particularly in the forwards, and are similar to the workloads of elite level rugby players. Keywords: rugby union, session rating of perceived exertion, workload monitoring, AC ratio, cost effectivenes

The impact of a fast bowling spell on physiological, perceptual and performance responses in non-elite cricketers

Background: The demands placed on fast bowlers may elicit unique responses that contribute towards increased injury risk and comprised performance capabilities. Despite this, very few investigations have attempted to quantify these demands and their impact on performance in cricketers.Objective: This investigation attempted to quantify the effects of a fast bowling protocol on the musculoskeletal, physiological and perceptual responses of fast bowlers; as well as ball speed and accuracy.Methods: Eight young adult bowlers (20 ± 2 years) participated in a 10-over bowling protocol that had been separated by intermittent fielding drills into three bowling spells respectively (4-, 3- and 3- overs). Selected responses were collected throughout the protocol.Results: Functional strength was measured and showed no change. Heart rate responses increased significantly (p<0.05) at the start of the bowling protocol. Local ratings of perceived exertion increased significantly (p<0.05) as a function of exercise duration, while low to moderate intensities of perceived discomfort were noted in the anterior and posterior shoulder areas, upper portion of the lower limb musculature, as well as in the middle and lower back regions. Performance responses experienced no significant change.Conclusion: There was no significant change in ball release speed and accuracy across the bowling protocol. Lower limb muscle power remained consistent and heart rates reached a steady state after the first over. In comparison, local ratings of perceived effort and body discomfort increased over time, which could mean that those unchanged measures do not accurately reflect fatigue or that perceptions are a more effective indicator of impending fatigue. Keywords: accuracy, speed, heart rate, body discomfort, ratings of perceived exertio

Physiological and Perceptual Demands During a Simulated “The Hundred” Batting Work-Bout in Female Cricketers

Purpose No research has investigated the physiological and perceptual demands of female cricket players at any level or for any format, making this study unique. This is despite the growth in popularity and professionalism of the women’s game. Therefore, the purpose of this study was to determine the physiological (heart rate, oxygen consumption) and perceptual (ratings of perceived exertion, body discomfort) demands of female cricketers during a simulated “The Hundred” protocol. Methods Twenty female cricketers (age: 19 ± 4.53 years, stature: 167.90 ± 7.28 cm; mass: 67.30 ± 13.51 kg) currently playing for a first-class county cricket club were recruited. The protocol consisted of six sets and was designed to mimic the nonpowerplay phase of a women’s “Hundred” match. Throughout the protocol selected physiological and perceptual responses were recorded. Results Heart rate responses increased significantly (P < 0.05) from the first set (149 ± 14 beats/min) until the end of the third set (167 ± 10 beats/min). A further significant decrease (P < 0.05) was observed between set three (167 ± 10 beats/min) and set six (165 ± 12 beats/min). Oxygen uptake responses increased significantly (P < 0.05) from set one (22.06 ± 7.82 mL/kg/min) until set three (26.30 ± 7.58 mL/kg/min). A significant difference (P < 0.05) was also observed between set three and all the other sets. Central ratings of perceived exertion increased significantly (P < 0.05) throughout the protocol (9 ± 1.83–13 ± 3.17). Body discomfort, results indicated that the quadriceps and calves were the areas that felt the most discomfort during the protocol. Conclusion In conclusion, the design of training programs should mimic the demandsof the women?s format of the game and focus on individualised exercise preparation

Do South African international cricket pace bowlers have similar bowling volume and injury risk associates compared to other elite fast bowlers?

BACKGROUND While many cricket-playing nations have conducted research on bowling volume (BV) and injury risk, this relationship among international South African pace bowlers is yet to be investigated. Environmental, socio-economic, and training strategy differences warrant similar research in a South African context. The purpose of this preliminary study was to establish if South African pace bowlers have similar bowling volume and injury associates compared to other elite fast bowlers. METHODS This study was a prospective, observational, cohort study that monitored match and training BV and injuries among pace bowlers playing for the South African national team between April 2017 and April 2019. A sample of convenience that included fourteen bowlers was selected. Bowling volume was quantified as the number of deliveries bowled during training and competition. Acute-, chronic- and acute: chronic bowling volume ratios were independently modeled as association variables. RESULTS There were 39 injuries with the most being to the lumbar spine (25.64%). Moderate-to-low and a moderate-to-high acute: chronic bowling load ratios were associated with a lower risk of injury. Chronic bowling load was associated with injury (z = 2.82, p = 0.01). A low acute workload, low chronic workload, moderate-high chronic workload, and moderate-low acute: chronic ratio was also associated with an increased risk of injury. CONCLUSION These findings confirm that there appears to be a dose-response effect between training bowling volume and the likelihood of an injury occurring with a moderate-to-low and a moderate-to-high bowling volume ratio being optimal. Considering the small sample size, the findings should be interpreted with caution

Azimuthal anisotropy and correlations in p+p, d+Au and Au+Au collisions at 200 GeV

We present the first measurement of directed flow ($v_1$) at RHIC. $v_1$ is found to be consistent with zero at pseudorapidities $\eta$ from -1.2 to 1.2, then rises to the level of a couple of percent over the range $2.4 < |\eta| < 4$. The latter observation is similar to data from NA49 if the SPS rapidities are shifted by the difference in beam rapidity between RHIC and SPS. Back-to-back jets emitted out-of-plane are found to be suppressed more if compared to those emitted in-plane, which is consistent with {\it jet quenching}. Using the scalar product method, we systematically compared azimuthal correlations from p+p, d+Au and Au+Au collisions. Flow and non-flow from these three different collision systems are discussed.Comment: Quark Matter 2004 proceeding, 4 pages, 3 figure

Azimuthal anisotropy: the higher harmonics

We report the first observations of the fourth harmonic (v_4) in the azimuthal distribution of particles at RHIC. The measurement was done taking advantage of the large elliptic flow generated at RHIC. The integrated v_4 is about a factor of 10 smaller than v_2. For the sixth (v_6) and eighth (v_8) harmonics upper limits on the magnitudes are reported.Comment: 4 pages, 6 figures, contribution to the Quark Matter 2004 proceeding

Partonic flow and ϕ\phi-meson production in Au+Au collisions at sNN\sqrt{s_{NN}} = 200 GeV

We present first measurements of the $\phi$-meson elliptic flow ($v_{2}(p_{T})$) and high statistics $p_{T}$ distributions for different centralities from $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions at RHIC. In minimum bias collisions the $v_{2}$ of the $\phi$ meson is consistent with the trend observed for mesons. The ratio of the yields of the $\Omega$ to those of the $\phi$ as a function of transverse momentum is consistent with a model based on the recombination of thermal $s$ quarks up to $p_{T}\sim 4$ GeV/$c$, but disagrees at higher momenta. The nuclear modification factor ($R_{CP}$) of $\phi$ follows the trend observed in the $K^{0}_{S}$ mesons rather than in $\Lambda$ baryons, supporting baryon-meson scaling. Since $\phi$-mesons are made via coalescence of seemingly thermalized $s$ quarks in central Au+Au collisions, the observations imply hot and dense matter with partonic collectivity has been formed at RHIC.Comment: 6 pages, 4 figures, submit to PR

Plasma Wakefield Acceleration with a Modulated Proton Bunch

The plasma wakefield amplitudes which could be achieved via the modulation of a long proton bunch are investigated. We find that in the limit of long bunches compared to the plasma wavelength, the strength of the accelerating fields is directly proportional to the number of particles in the drive bunch and inversely proportional to the square of the transverse bunch size. The scaling laws were tested and verified in detailed simulations using parameters of existing proton accelerators, and large electric fields were achieved, reaching 1 GV/m for LHC bunches. Energy gains for test electrons beyond 6 TeV were found in this case.Comment: 9 pages, 7 figure

The energy dependence of ptp_t angular correlations inferred from mean-ptp_{t} fluctuation scale dependence in heavy ion collisions at the SPS and RHIC

We present the first study of the energy dependence of $p_t$ angular correlations inferred from event-wise mean transverse momentum fluctuations in heavy ion collisions. We compare our large-acceptance measurements at CM energies $\sqrt{s_{NN}} =$ 19.6, 62.4, 130 and 200 GeV to SPS measurements at 12.3 and 17.3 GeV. $p_t$ angular correlation structure suggests that the principal source of $p_t$ correlations and fluctuations is minijets (minimum-bias parton fragments). We observe a dramatic increase in correlations and fluctuations from SPS to RHIC energies, increasing linearly with $\ln \sqrt{s_{NN}}$ from the onset of observable jet-related fluctuations near 10 GeV.Comment: 10 pages, 4 figure