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José María González-Ravé, Francisco Hermosilla, Fernando González-Mohíno, Arturo Casado, and David B. Pyne

A well-planned periodized approach allows swimmers to achieve peak performance at the major national and international competitions. Purpose: To identify the main characteristics of endurance training for highly trained swimmers described by the training intensity distribution (TID), volume, and periodization models. Methods: The electronic databases Scopus, PubMed, and Web of Science were searched using a comprehensive list of relevant terms. Studies that investigated the effect of the periodization of training in swimming, with the training load (volume, TID) and periodization reported, were included in the systematic review. Results: A total of 3487 studies were identified, and after removal of duplicates and elimination of papers based on title and abstract screening, 17 articles remained.  A further 8 articles were excluded after full text review, leaving a final total of 9 studies in the systematic review. The evidence levels were 1b for intervention studies (n = 3) and 2b for (observational) retrospective studies (n = 6). The sprint swimmers typically followed a polarized and threshold TID, the middle-distance swimmers followed a threshold and pyramidal TID, and the long-distance swimmers primarily followed a pyramidal TID. The periodization model identified in the majority of studies selected is characterized by wave-like cycles in units like mesocycles to promote physiological adaptations and skill acquisition. Conclusions: Highly trained swimmers follow a training volume and TID based on their primary event. There is a need for further experimental studies on the effects of block and reverse periodization models on swimming performance. Although observational studies of training have limited evidence, it is unclear whether a different training/periodization approach would yield better results.

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Eugene C. Fitzhugh, Jerry Everett, and Linda Daugherty

Background: School-aged children in the Southeast, compared with other United States of America (US) regions, have significantly lower levels of active transportation to school (ATS). The purpose of this study was to contrast the parental correlates of ATS choice specific to the Southeast with other areas of the US. Methods: This study utilized national data from 2952 households with school-aged children located within a 20-minute walk to a school. Parents reported their children’s ATS behavior and their own ATS beliefs and perceptions. Logistic regression contrasted correlates of parents from the Southeast with other regions. Results: Parents in the Southeast, compared with parents across the US, were significantly less likely to allow their child to take ATS (12.9% vs 33.3%, respectively) (odds ratio [OR] = 0.46; 95% confidence interval [CI] = 0.36–0.59). Specific to the Southeast, parental correlates linked to increases in ATS were Black race/ethnicity (OR = 1.68; 95% CI, 1.31–2.60), being single, (OR = 1.71; 95% CI, 1.15–2.54), and any parental physical activity (P value for trend = .0053). The only correlate associated with a decrease in ATS in the Southeast was heightened safety concerns (eg, traffic speed, safe crossings) (OR = 0.44; 95% CI, 0.23–0.84). Conclusions: Among households with children in the Southeast, ATS interventions that allay parental safety concerns and that promote physical activity among parents might lead to increases in ATS.

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A. Dallaway, J. Hattersley, J. Tallis, D. Renshaw, C. Griffen, and M. Duncan

This study investigated age-related changes in trunk muscle function in healthy men and the moderating effect of physical activity. Twelve older (67.3 ± 6.0 years) and 12 younger (24.7 ± 3.1 years) men performed isokinetic trunk flexion and extension tests across a range of angular velocities (15°/s–180°/s) and contractile modes (concentric and eccentric). For concentric trunk extension, mixed-effects analysis of covariance revealed a significant interaction between Angular velocity × Age group (p = .026) controlling for physical activity. Follow-up univariate analysis of covariance revealed that the younger group produced significantly greater peak torque for all concentric extension conditions. Eccentric trunk strength was somewhat preserved in the older group. Age-related changes in trunk strength were independent of physical activity. The normal loss of trunk muscle strength in older age is muscle- and contractile-mode specific. These findings provide guidance for effective intervention strategies to offset adverse health outcomes related to trunk strength loss in older adults.

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Hillary H. Holmes, Randall T. Fawcett, and Jaimie A. Roper

Walking is an integral indicator of human health commonly investigated while walking overground and with the use of a treadmill. Unlike fixed-speed treadmills, overground walking is dependent on the preferred walking speed under the individuals’ control. Thus, user-driven treadmills may have the ability to better simulate the characteristics of overground walking. This pilot study is the first investigation to compare a user-driven treadmill, a fixed-speed treadmill, and overground walking to understand differences in variability and mean spatiotemporal measures across walking environments. Participants walked fastest overground compared to both fixed and user-driven treadmill conditions. However, gait cycle speed variability in the fixed-speed treadmill condition was significantly lower than the user-driven and overground conditions, with no significant differences present between overground and user-driven treadmill walking. The lack of differences in variability between the user-driven treadmill and overground walking may indicate that the user-driven treadmill can better simulate the variability of overground walking, potentially leading to more natural adaptation and motor control patterns of walking.