Sunglass tint does not impact the indoor catching performance of cricket fielders.

Introduction: Sunglasses are worn by outdoor athletes such as cricketers for many reasons, including comfort and glare reduction, which may help to improve vision. Anecdotally they are purported to have performance-enhancing benefits, but there is a lack of evidence for this. Further, it appears that fielders are the only position in cricket who wear sunglasses. Therefore, this study aimed to compare the catching performance of fielders when wearing three different colour sunglasses tints during an indoor, laboratory-based experiment. Methods: Twenty-one male cricketers currently playing for a university or amateur provincial teams in Makhanda, South Africa, who were non-habitual sunglass wearers, were recruited for this study. An optometrist administered pre-screening tests. Players had four testing sessions during which they wore a different colour tint at each session indoors (clear, blue, G30 (rose), and red). Players were required to catch 18 balls projected from a bowling machine. The number of balls caught, as well as the quality of the catch, was recorded. At the final session, they were asked which tint they thought was best. Results: Pre-screening tests showed that the red lens was best for contrast sensitivity and stereopsis. During data collection, sunglass tint did not affect catching performance. The players perceived the red lens as the worst and the G30 as the best. Discussion: It can be concluded that catching performance indoors is not affected by tint colour.

The impact of sleep, physical activity and sedentary behaviour on symptoms of depression and anxiety before and during the COVID-19 pandemic in a sample of South African participants.

During lockdowns associated with the COVID-19 pandemic, individuals have experienced poor sleep quality and sleep regularity, changes in lifestyle behaviours, and heightened depression and anxiety. However, the inter-relationship and relative strength of those behaviours on mental health outcomes is still unknown. We collected data between 12 May and 15 June 2020 from 1048 South African adults (age: 32.76 ± 14.43 years; n = 767 female; n = 473 students) using an online questionnaire. Using structural equation modelling, we investigated how insomnia symptoms, sleep regularity, exercise intensity/frequency and sitting/screen-use (sedentary screen-use) interacted to predict depressive and anxiety-related symptoms before and during lockdown. We also controlled for the effects of sex and student status. Irrespective of lockdown, (a) more severe symptoms of insomnia and greater sedentary screen-use predicted greater symptoms of depression and anxiety and (b) the effects of sedentary screen-use on mental health outcomes were mediated by insomnia. The effects of physical activity on mental health outcomes, however, were only significant during lockdown. Low physical activity predicted greater insomnia symptom severity, which in turn predicted increased depressive and anxiety-related symptoms. Overall, relationships between the study variables and mental health outcomes were amplified during lockdown. The findings highlight the importance of maintaining physical activity and reducing sedentary screen-use to promote better sleep and mental health.

Strength and conditioning practices of franchise-level cricket trainers.

Background: The purpose of this investigation was to determine the strength and conditioning practices implemented by cricket trainers and coaches at an elite level. Methods: An online survey, adapted from previous strength and conditioning questionnaires, was sent to trainers currently working with the franchise cricket teams in South Africa. The survey consisted of four main sections including a general strength and conditioning, cricket- specific and injury prevention category. Results: The results indicated that trainers (n = 5) implement planned sessions throughout the different phases of the season and that certain injury prevention practices are applied. Furthermore, player workload is monitored for all disciplines (batsmen, bowlers and fielders). Conclusion: These results can be used as a tool to educate coaches and trainers to ensure the correct strength and conditioning practices are implemented. Additionally the study showed that strength and conditioning practices at the elite level can be implemented without specialised equipment and facilities, which is important for teams that are constantly travelling. Lastly it showed the importance of looking at all aspects of health and skill related fitness.

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.

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.

Impact of ceiling restriction and lifting barriers on selected physiological and perceptual responses.

OBJECTIVE: To compare physiological and perceptual responses while lifting with different combinations of ceiling restriction and horizontal reach. METHODS: Four lifting conditions with different combinations of ceiling height ('normal' (N) or reduced (R) to 1460 mm) and reach demands (400 mm (N) and 800 mm (F)) were tested. PARTICIPANTS: Thirty two physically active male participants were recruited. RESULTS: Heart rate and oxygen uptake were significantly lower in the URN condition compared to all other conditions. The RF condition was significantly more taxing than all the other conditions. EE was significantly lower between the URN condition and the RN and URF conditions. Central RPE was significantly higher in the RF condition compared to the URN condition. Local RPE was significantly lower comparing the URN and RF conditions. The effect of reach was perceived to have a significant effect on both cardiovascular and musculoskeletal demands whereas ceiling height only had a significant effect on musculoskeletal demands. The greatest discomfort was experienced in the lower back with the most intense discomfort occurring in the RN condition. CONCLUSIONS: The RF condition placed the most strain on the participants and the URN, the least strain. The other two conditions were comparable and placed moderate strain on the participants.

HLA antigens in HBsAg infection.

The HLA typing of hemodialysis patients and normal subjects suggests a negative association of B8 and positive association of B5 with the development of anti-HBs and a negative association of BW35 with HBsAg antigenemia.