Objectives 
The main purpose of the present meta-analysis was to examine the criterion-related validity of the distance- and time-based walk/run tests for estimating cardiorespiratory fitness among apparently healthy children and adults.


Materials and Methods 
Relevant studies were searched from seven electronic bibliographic databases up to August 2015 and through other sources. The Hunter-Schmidt’s psychometric meta-analysis approach was conducted to estimate the population criterion-related validity of the following walk/run tests: 5,000 m, 3 miles, 2 miles, 3,000 m, 1.5 miles, 1 mile, 1,000 m, ½ mile, 600 m, 600 yd, ¼ mile, 15 min, 12 min, 9 min, and 6 min.


Results 
From the 123 included studies, a total of 200 correlation values were analyzed. The overall results showed that the criterion-related validity of the walk/run tests for estimating maximum oxygen uptake ranged from low to moderate (rp = 0.42–0.79), with the 1.5 mile (rp = 0.79, 0.73–0.85) and 12 min walk/run tests (rp = 0.78, 0.72–0.83) having the higher criterion-related validity for distance- and time-based field tests, respectively. The present meta-analysis also showed that sex, age and maximum oxygen uptake level do not seem to affect the criterion-related validity of the walk/run tests.


Conclusions 
When the evaluation of an individual’s maximum oxygen uptake attained during a laboratory test is not feasible, the 1.5 mile and 12 min walk/run tests represent useful alternatives for estimating cardiorespiratory fitness. As in the assessment with any physical fitness field test, evaluators must be aware that the performance score of the walk/run field tests is simply an estimation and not a direct measure of cardiorespiratory fitness.

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Criterion-Related Validity of the Distance- and Time-Based Walk/Run Field Tests for Estimating Cardiorespiratory Fitness: A Systematic Review and Meta-Analysis.

Chaabene, H, Negra, Y, Bouguezzi, R, Mkaouer, B, Franchini, E, Julio, U, and Hachana, Y. Physical and physiological profile of wrestler athletes: a short review. J Strength Cond Res 31(5): 1411-1442, 2017-Wrestling is one of the oldest combat sports, disputed since the ancient Greek Olympic Games. This combat sport discipline has caught the attention of scientists since 1943 which is the date that matches the appearance of the first scientific research dealing with wrestling. The current short review aimed to summarize and critically analyze the scientific literature related to wrestling's physical and physiological attributes and to provide practical recommendations for testing/training together with new perspective and areas of future scientific research. Regardless of sex and wrestling styles, an optimal level of cardiorespiratory fitness is important to help sustaining effort throughout the duration of the match and to stimulate the recovery process between periods. With regard to the anaerobic power and capacity, the available studies were in agreement about their critical importance toward reaching high-level wrestling success since these variables have discriminated well between successful and less-successful wrestlers regardless of age, weight classes, and wrestling styles. Physical fitness parameters such as maximal dynamic strength, isometric strength, explosive strength, and strength endurance are closely related to high-level wrestling performance. However, flexibility level seems not to be one of the key fitness variables that help to reach high-level wrestling success. Overall, to achieve high-level wrestling performance, training should be directed to develop anaerobic power and capacity, aerobic power, maximal dynamic and isometric strength, explosive strength, and strength endurance.

Physical and Physiological Attributes of Wrestlers: An Update.

Background: Lockdowns to prevent the community transmission of COVID-19 pandemic has confined the people at home and imposed social restrictions, which is expected to cause alterations in circadian driven sleep-wake schedule and its associated lifestyle behaviors. Design and Methods: An online questionnaire-based survey was conducted to assess the impact of lockdown on the sleepwake pattern, meal timings and digital media exposure time on the Indian population during lockdown. Responses of 1511 participants (age ≥18 years) were analyzed to assess the effect of gender and age on these parameters before and during lockdown. Results: The sleep onset-wakeup times and meals' time was significantly delayed during lockdown, which was more pronounced in younger subjects. However, young individuals reported increased sleep duration at this time. Increased digital media duration was evident in all age groups, mainly in males. However, females reported more delay in sleep onset-waking time and first meal timing with longer sleep duration during lockdown. Conclusions: Discord with social and natural cues due to complete lockdown during COVID-19 pandemic leads to a state of social jetlag with delayed sleep-wake, meal timings and excessive digital media exposure among Indians, which has differential impact on males and females as well as across different age groups. These findings have applied implications in sleep health and related behavior during longer social isolation conditions such as current COVID-19 or similar situations and may help to prepare better for any such future events.

Impact of COVID-19 lockdown on sleep-wake schedule and associated lifestyle related behavior: A national survey

Physicians who care for children are often called upon to render advice on sports and exercise. Long before the physical fitness fad struck the adult sector, children used sports to have fun, work off steam, test themselves against their peers, and learn about real life. Their physicians, once called on only to tend their wounds, now must be prepared to advise on exercise appropriate to age, size, development, and any concurrent disease, and to control access to many competitive activities. This well-written, carefully documented book provides a great deal of information by which such decisions can be informed. Its extended title accurately describes the focus of the book: exercise physiology in the immature human, with special applications to children with several forms of chronic disorders. Two initial chapters clearly describe the response of children of differing age, sex, and size to exercise. Applications to children with pulmonary, cardiovascular, endocrine, nutritional,

Pediatric Sports Medicine for the Practitioner: From Physiologic Principles to Clinical Applications

Moran, J, Clark, CCT, Ramirez-Campillo, R, Davies, MJ, and Drury, B. A meta-analysis of plyometric training in female youth: its efficacy and shortcomings in the literature. J Strength Cond Res 33(7): 1996-2008, 2019-This meta-analysis characterized female youths' adaptability to plyometric training (PT). A second objective was to highlight the limitations of the body of literature with a view to informing future research. Fourteen studies were included in the final analysis. The effect size (ES = Hedges' g) for the main effect of vertical jump performance was "small" (ES = 0.57, 95% confidence interval: 0.21-0.93). Effect sizes were larger in younger ( 2; ES = 1.22 [0.18-2.25] vs. 0.37 [0.02-0.71]), and whose sessions were of longer duration (≥30 minutes ES = 1.16 [0.14-2.17] vs. 0.33 [0.03-0.63]). More than 16 sessions per program (0.85 [0.18-1.51]) was more effective than exactly 16 sessions (0.46 [0.08-0.84]) which, in turn, was more effective than less than 16 (0.37 [-0.44 to 1.17]). These findings can inform the prescription of PT in female youth.

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A Meta-Analysis of Plyometric Training in Female Youth: Its Efficacy and Shortcomings in the Literature.

Purpose: Athletes are faced with competitive surrounding all the time where they are required to perform at high levels in high-pressure situations. This can often lead to anxiety so the aim of this study was to investigate levels of trait anxiety among elite, national team Croatian junior and U23 male wrestlers and to examine differences in trait anxiety between national team members in 2010 and 2017. Methods: The study was conducted on two different groups of athletes, each tested at one time period (one group was tested in 2010 and the other in 2017). The participants were Croatian junior and U23 greco-roman national team members at the time when testing was conducted (N2010=16; N2017=9). We used a theory of competitive anxiety (Martens, Vealy, and Burton, 1990) and Croatian version of SCAT questionnaire (Sport Competition Anxiety Test, Martens,1977) to measure levels of trait anxiety in elite wrestlers. Descriptive statistics, as well as Mann-Whithey U-test, were used to examine the levels of trait anxiety and the difference between two groups of national team members. Results: There was no difference in trait anxiety levels between members of junior and U23 wrestling national team in 2010 and 2017 suggesting these two groups experienced similar levels of precompetition anxiety. Conclusions: These results can help in further understanding which are the levels of trait anxiety for elite wrestlers.

Assessment of trait anxiety levels on elite junior and U23 Croatian wrestlers

Optimal age to begin with Greco-Roman wrestling and reach peak performance – trends in cases of world-class medal winners of various weight groups

Background and Study Aim. In the basis of the boxer's power qualities is the ability to perceive and process external information. Therefore, in order to ensure the proper training of qualified boxers, there is a need to monitor the functional state of the boxer’s organism. The relationship between cognitive functions and special working capacity of elite boxers were studied. 
Material and Methods. The level of special working capacity was studied by the test of punching a boxer for 8 s at maximum speed. Cognitive functions (verbal and nonverbal intelligence, and word memory) were studied using the "Multipsychometer-05" hardware-software. 26 elite boxers, aged 18-24, were tested. 
Results. The research results showed that groups of boxers with different levels of special working capacity differ in terms of accuracy and efficiency when performing a cognitive task with verbal stimuli. The resulted that the high level of special working capacity of elite boxers is provided by the manifestation of verbal intelligence. Besides, the special working capacity is related with activation of mental functions of attention, speed of visual perception, operational and logical thinking. At the same time, significantly higher values of decision latency in this group of boxers indicate a slowdown in the processing of nonverbal information in boxers with a high level of special working capacity to work. It can be noted that the special working capacity of boxers has a direct relationship with quality and inverse relationship with the speed of information processing. The speed of memorizing verbal information is better in boxers with a high level of special working capacity. This fact indicates the importance of the verbal factor for the assimilation of special information in the training of boxers. The best values of accuracy and efficiency indicate the relationship of special working capacity in skilled boxers with the quality and volume of memorized verbal information. 
Conclusions. The special working capacity of elite boxers has a direct relationship with quality and inverse relationship with the speed of information processing. The elite boxers with a high level of special working capacity have a better speed of verbal information memorizing.

Mario Baić

Papers

Assessment of trait anxiety levels on elite junior and U23 Croatian wrestlers

Optimal age to begin with Greco-Roman wrestling and reach peak performance – trends in cases of world-class medal winners of various weight groups

Cognitive functions and special working capacity in elite boxers