The differential impact of several types of sports on pulmonary functions and respiratory muscle strength in boys aged 8–12

EXERCISE FATIGUE INJURY UNDER SPORT RESISTANCE

ABSTRACT Introduction Athletes are prone to local muscle fatigue due to high-intensity training and to long-term accumulation of musculoskeletal injuries. Musculoskeletal complications represent a large proportion of occupational health problems and, for this reason, have received increased attention from the sports industry. In this sense, studies on muscle fatigue should be intensified. Objective Verify muscle fatigue and injury involving the strain characteristics of lower limb joints in the eccentric and centripetal contraction of the jump. Methods A total of 691 individuals aged 20 to 40 years were selected. Fatigue was caused by active muscle contraction. The characteristic curves of active muscle contraction in different isometric, isotonic, and isokinetic training were analyzed. The degree of fatigue caused by three different sports states was tested by experimentation. The corresponding active muscle contraction characteristics were also analyzed. The potential for homeostasis at different ages was compared. Results The delay in recovery to fatigue is directly proportional to the athlete’s age. The return to post-exercise relief proportion from fatigue gradually decreases. Conclusion The experimental results showed that active muscle contraction could reduce exercise fatigue to some extent. This beneficial biochemical property of active muscle contraction is not found in people with advanced age. The findings have a guiding potential for the relief of sports fatigue. Evidence Level II; Therapeutic Studies - Investigating the result.

Anthropometric and Motor Competence Classifiers of Swimming Ability in Preschool Children-A Pilot Study

Swimming is a form of physical activity and a life-saving skill. However, only a few studies have identified swimming ability classifiers in preschool children. This pilot cross-sectional study aimed to find anthropometric (AM) and motor competence (MC) predictors of swimming ability in preschool children, by building classifiers of swimming ability group (SAG) membership. We recruited 92 children (girls n = 45) aged 5-6 years and took the AM and MC measurements in accordance with the reference manual and using the KTK battery test (motor quotient, MQ), respectively. A linear discriminant analysis tested a classification model of preschoolers' swimming ability (SAG: POOR, GOOD, EXCELLENT) based on gender, age, AM, and MC variables and extracted one significant canonical discriminant function (model fit: 61.2%) that can differentiate (group centroids) POOR (-1.507), GOOD (0.032), and EXCELLENT (1.524). The MQ total was identified as a significant classifier, which absolutely contributed to the discriminant function that classifies children's swimming ability as POOR (standardized canonical coefficient: 1.186), GOOD (1.363), or EXCELLENT (1.535) with an accuracy of 64.1%. Children with higher MQ total ought to be classified into higher SAG; thus, the classification model of SAG based on the MQ total is presented.