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Saša Krstulović, Andrea De Giorgio, Óscar DelCastillo Andrés, Emerson Franchini and Goran Kuvačić

The main aim of this investigation was to determine the effect of high contextual interference (HCI) and low contextual interference (LCI) on motor learning of falling techniques. Thirty-five kinesiology students (21 males and 14 females; mean ± SD, age = 19.4 ± 0.69 years) were randomly assigned to the HCI or LCI practice group. The participants’ task was to learn two judo falling techniques on both sides over 3 weeks. The two-way analysis of variance found no difference between LCI and HCI in the performance at the pretest, posttest, retention, and transfer. Both groups improved posttest and retention performance. Finally, differences were found for both groups between the falling performance in the posttest and the application test (except for the right yoko ukemi fall in the HCI). Lower application test scores led to the conclusion that the 3-week treatment was insufficient to reach the application level of the falling techniques.

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Katie E. McGibbon, David B. Pyne, Laine E. Heidenreich and Robin Pla

Purpose: Pacing, or the distribution of energy expenditure, is particularly important in swimming; however, there is limited research examining pacing profiles in long-distance freestyle events. This study aimed to characterize the pacing profiles of elite male 1500-m freestyle swimmers using a novel method to provide a detailed analysis of different race segments. Methods: The race data for 327 male 1500-m freestyle long-course races between 2010 and 2019 were analyzed retrospectively. The raw 50-m split times for each lap were converted to a percentage of overall race time. The races were classified as a fast-, average-, or slow-start strategy (laps 1–2); as an even, negative, or positive pacing strategy (laps 3–28); and as a fast-, average-, or slow-finish strategy (laps 29–30) to give an overall pacing profile. Results: Slow- and average-start strategies were associated with faster overall 1500-m times than a fast-start strategy (mean = −21.2 s; 90% confidence interval, −11.4 to −32.3 s, P = .00). An even pacing strategy in laps 3 to 28 yielded faster overall 1500-m times than a positive pacing strategy (−8.4 s, −3.9 to −13.0 s, P = .00). The overall 1500-m times did not differ substantially across the finish strategies (P = .99). The start strategy differed across age groups and nationalities, where younger swimmers and swimmers from Australia and Great Britain typically spent a lower percentage of race time in laps 1 to 2 (faster start strategy; −0.10%, −0.01% to −0.23%, P ≤ .02). Conclusion: Adopting a relatively slower start strategy helps conserve energy for the latter stages of a 1500-m freestyle race.

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Dionne A. Noordhof, Sjur J. Øfsteng, Linnea Nirenberg, Daniel Hammarström, Joar Hansen, Bent R. Rønnestad and Øyvind Sandbakk

Performance-determining variables are usually measured from a rested state and not after prolonged exercise, specific to when athletes compete for the win in long-distance events. Purpose: (1) To compare cross-country skiing double-poling (DP) performance and the associated physiological and biomechanical performance-determining variables between a rested state and after prolonged exercise and (2) to investigate whether the relationship between the main performance-determining variables and DP performance is different after prolonged submaximal DP than when tested from a rested state. Methods: Male cross-country skiers (N = 26) performed a blood lactate profile test and an incremental test to exhaustion from a rested state on day 1 (D1; all using DP) and after 90-minute submaximal DP on day 2 (D2). Results: The DP performance decreased following prolonged submaximal DP (D1: peak speed = 15.33–20.75 km·h−1, median = 18.1 km·h−1; D2: peak speed = 13.68–19.77 km·h−1, median = 17.8 km·h−1; z = −3.96, P < .001, effect size r = −.77), which coincided with a reduced submaximal gross efficiency and submaximal and peak cycle length, with no significant change in peak oxygen uptake (P = .26, r = .23). The correlation coefficient between D1 cycle length at 12 km·h−1 and D2 performance is significantly smaller than the correlation coefficient between D2 cycle length at 12 km·h−1 and D2 performance (P = .033), with the same result being found for peak cycle length (P < .001). Conclusions: The reduced DP performance after prolonged submaximal DP coincided with a reduced submaximal gross efficiency and shorter peak cycle length. The results indicate that performance-determining variables could be determined after prolonged exercise to gain more valid insight into long-distance DP performance.

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Nicholas G. Gomez, Kelton K. Gubler, Kenneth Bo Foreman and Andrew S. Merryweather

The factors that contribute to the difficulties persons with Parkinson Disease (PwPD) have when negotiating transitions in walking surfaces are not completely known. The authors investigated if PwPD adjusted their step characteristics when negotiating a familiar outdoor surface transition between synthetic concrete and synthetic turf. Force plate and motion capture data were collected for 10 participants with mild to moderate Parkinson disease and 5 healthy older control participants ambulating bidirectionally across the transition between synthetic concrete and synthetic turf. Between groups, PwPD had a significantly higher minimum toe clearance (P = .007) for both directions of travel compared with the healthy control group. Within groups, PwPD significantly increased their hip (P < .001) and ankle (P = .016) range of motion walking from concrete to turf, while the healthy control participants significantly increased their minimum toe clearance (P = .013), margin of stability (P = .019), hip (P < .001) and ankle (P = .038) range of motion, and step length (P < .001). Walking from turf to concrete, both the Parkinson disease group (P = .014) and the healthy control group (P < .001) increased their knee range of motion. Both groups adjusted their step characteristics when negotiating known surface transitions, indicating that surface transitions result in step changes regardless of health status. However, PwPD exhibited overcompensations, particularly in their minimum toe clearance.

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Andrew M. Colombo-Dougovito and Jihyun Lee

Researchers posit that physical activity (PA) settings may provide an increased opportunity for social interaction. However, little consensus exists regarding the construct of social skills. Moreover, little is known about what type or amount of PA is necessary for individuals on the autism spectrum to benefit from this increased interaction. Thus, this scoping review synthesized the components (e.g., design, participants, independent and dependent variables, etc.) and findings of PA-based interventions that included social skill components to identify how interventions have incorporated these skills in different settings. Based on a review of 25 articles, this review revealed a great deal of variability in the types of PA, social skills, and instruments studied, as well as the intensity of intervention delivery in the published findings. No longitudinal studies were identified as a part of the search. These results provide a foundation for the design of effective PA-based interventions that may have an increased impact on the social skills of individuals on the autism spectrum. Future research should employ longitudinal designs to capture the relationship between social skills and PA, as well as to increase the likelihood of capturing change.

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Jordan L. Fox, Robert Stanton, Aaron T. Scanlan, Masaru Teramoto and Charli Sargent

Purpose: To investigate the associations between sleep and competitive performance in basketball. Methods: A total of 7 semiprofessional, male players were monitored across the in-season. On nights prior to competition, sleep duration and quality were assessed using actigraphs and sleep diaries. The data were accumulated over 1 (night 1), 2 (nights 1–2 combined), 3 (nights 1–3 combined), and 4 (nights 1–4 combined) nights prior to competition. Performance was reported as player statistics (field goal and free-throw accuracy, rebounds, assists, steals, blocks, and turnovers) and composite performance statistics (offensive rating, defensive rating, and player efficiency). Linear regression analyses with cluster-robust standard errors using bootstrapping (1000 replications) were performed to quantify the association between sleep and performance. Results: The night before competition, subjective sleep quality was positively associated with offensive rating and player efficiency (P < .05). Conclusions: Strategies to increase subjective sleep quality the night before competition should be considered to increase the likelihood of successful in-game performance, given its association with composite performance metrics.

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Jessica A. Calderbank, Paul Comfort and John J. McMahon

Purpose: The aim of the current study was to investigate the relationship between dive distance (DD) and countermovement jump (CMJ) height, track start CMJ height, countermovement broad jump (CMBJ) distance, track start broad jump distance, and isometric midthigh pull peak force and relative peak force. Methods: A total of 27 (11 female and 16 male) regional-national-international-standard swimmers (mean [SD]; age = 19.5 [5.5] y; mass = 69.3 [10.5] kg; height = 1.77 [0.09] m) performed 3 trials of a track start dive, CMJ, track start CMJ, CMBJ, track start broad jump, and isometric midthigh pull. Results: Data were separated into pooled (females and males combined), females, and males. Large to very large correlations were found between DD and all variables tested for pooled data (r = .554–.853, P < .001–.008), with DD-CMBJ displaying the highest correlation (r = .853, P < .001). CMBJ accounted for 70% of the variance in DD. Females demonstrated moderate nonsignificant correlations between DD isometric midthigh pull (r = .379, P < .125). Males demonstrated very large significant correlations between DD-CMJ (r = .761, P < .001). Conclusions: DD demonstrated strong correlations with jump performances and multijoint isometric force production in pooled data. Males showed stronger correlations than females due to being stronger and being able to perform the jumping/strength tasks to a higher standard. Enhanced jump performance and increased maximal force production may, therefore, enhance DD in swimmers.

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Luca Pollastri, Gabriele Gallo, Milena Zucca, Luca Filipas, Antonio La Torre, Ugo Riba, Luigi Molino and Elisabetta Geda

Background: The effects of anodal transcranial direct-current stimulation (tDCS) on endurance exercise performance are not yet fully understood. Different stimulated areas and low focality of classical tDCS technique may have led to discordant results. Purpose: This study investigated the effect of a bilateral anodal high-definition tDCS (HD-tDCS) of the dorsolateral prefrontal cortex on the cycling time-trial (TT) performance and physiological and perceptual response at moderate intensity in elite cyclists. Methods: A total of 8 elite cyclists (maximal oxygen consumption: 72.2 [4.3] mL·min−1·kg−1) underwent in a double-blind, counterbalanced, and randomized order the experimental treatment (HD-tDCS) or control treatment (SHAM). After 20 minutes of receiving either HD-tDCS on the dorsolateral prefrontal cortex (F3 and F4) or SHAM stimulation, the participants completed a constant-load trial (CLT) at 75% of the second ventilatory threshold. Thereafter, they performed a simulated 15-km TT. The ratings of perceived exertion, heart rate, cadence,  oxygen consumption, and respiratory exchange ratio were recorded during the CLT; the ratings of perceived exertion and heart rate were recorded during the TT. Results: The total time to complete the TT was 1.3% faster (HD-tDCS: 1212 [52] s vs SHAM: 1228 [56] s; P = .04) and associated with a higher heart rate (P < .001) and a tendency toward higher mean power output (P = .05). None of the physiological and perceptual variables measured during the CLT highlighted differences between the HD-tDCS and SHAM condition. Conclusions: The findings suggest that bilateral HD-tDCS on the dorsolateral prefrontal cortex improves cycling TT performance without altering the physiological and perceptual response at moderate intensity, indicating that an upregulation of the prefrontal cortex could enhance endurance exercise performance.

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ZáNean McClain, Daniel W. Tindall and Jill Pawlowski

Open access

Paddy C. Dempsey, Christine M. Friedenreich, Michael F. Leitzmann, Matthew P. Buman, Estelle Lambert, Juana Willumsen and Fiona Bull

Background: In 2020, the World Health Organization (WHO) released global guidelines on physical activity (PA) and sedentary behavior, for the first time providing population-based recommendations for people living with selected chronic conditions. This article briefly presents the guidelines, related processes and evidence, and, importantly, considers how they may be used to support research, practice, and policy. Methods: A brief overview of the scope, agreed methods, selected chronic conditions (adults living with cancer, hypertension, type 2 diabetes, and human immunodeficiency virus), and appraisal of systematic review evidence on PA/sedentary behavior is provided. Methods were consistent with World Health Organization protocols for developing guidelines. Results: Moderate to high certainty evidence (varying by chronic condition and outcome examined) supported that PA can reduce the risk of disease progression or premature mortality and improve physical function and quality of life in adults living with chronic conditions. Direct evidence on sedentary behavior was lacking; however, evidence extrapolated from adult populations was considered applicable, safe, and likely beneficial (low certainty due to indirectness). Conclusions: Clinical and public health professionals and policy makers should promote the World Health Organization 2020 global guidelines and develop and implement services and programs to increase PA and limit sedentary behavior in adults living with chronic conditions.