Browse

You are looking at 71 - 80 of 24,779 items

Open access

Sigridur L. Gudmundsdottir

Purpose: Insufficient sleep duration may affect athletic performance and health. Inconsistent sleep pattern also has negative health effects, but studies on athletes’ intraindividual sleep variability are scarce. The aim of this research was to compare total sleep time (TST) and variability (TST-variability), wakening after sleep onset, and sleep efficiency, during nights preceding early morning practices with other nights, and to investigate sleep characteristics of nights following a day with early morning only, evening only, or both a morning and an evening session in adolescent swimmers. Methods: Wrist-worn accelerometers were used to measure 1 week of sleep in 108 swimmers (mean age 16.1 [2.6] y) in Iceland. Adjusted regression analyses and linear mixed models were used to explore associations of training schedules with TST, TST-variability, wakening after sleep onset, and sleep efficiency. Results: Mean TST was 6:32 (h:min) (±39 min) and TST-variability was 63 minutes (±25 min). TST decreased and TST-variability increased with more early morning practices. TST preceding early training was 5:36 and 5:06 in <16- and ≥16-year-olds, respectively, shorter than on nights preceding later or no morning training (P < .001). Conclusion: Swimmers have extremely short TST preceding early morning sessions and increased TST-variability with more early morning sessions.

Restricted access

Sebastian Klich, Bogdan Pietraszewski, Matteo Zago, Manuela Galli, Nicola Lovecchio and Adam Kawczyński

Objectives: The aim of the study was to investigate supraspinatus tendon thickness, acromiohumeral distance (AHD), and stiffness/creep measures of the shoulder girdle in overhead asymptomatic athletes in muscle fatigue conditions. Design: Observational, case series study. Setting: Biomechanics and motion analysis lab. Participants: Twenty-four male overhead volleyball (n = 8), handball (n = 8), and tennis (n = 8) athletes. All subjects were without shoulder injury history. Main Outcome Measure: The subjects were tested for supraspinatus tendon thickness (in short and long axis), AHD using ultrasound scans and stiffness/creep of upper trapezius, infraspinatus, anterior and posterior deltoid, and pectoralis major using the myotonometer device before and immediately after a fatigue protocol. Intervention: The fatigue protocol consisted of 3 sets of 32 maximum isokinetic concentric contractions performing shoulder internal and external rotation at isokinetic speed of 120°/s. Results: A significant increase in supraspinatus tendon thickness (both in short and long axis) (P = .045 and P = .01, respectively) and a reduction in AHD (P = .01) were found after an isokinetic protocol. The stiffness increased significantly in upper trapezius (P ≤ .01), infraspinatus (P = .003), posterior deltoid (P = .047), and pectoralis major (P = .01), whereas the creep showed a significant decrement for upper trapezius (P = .001) and infraspinatus (P = .003). Conclusion: The present study has demonstrated the postexercise fatigue in overhead athletes. The increase of stiffness (reduction of muscle creep) and tendon thickness (simultaneous to the reduction of AHD) may indicate rotator cuff overloading as a primary intrinsic tendon pathology process.

Restricted access

Élvio R. Gouveia, Andreas Ihle, Bruna R. Gouveia, Matthias Kliegel, Adilson Marques and Duarte L. Freitas

Objective: To investigate the relations of balance to muscle mass (MM) and muscle strength (MS), depending on age and physical activity, which is of particular importance to functional independence in older people. Methods: This cross-sectional study included 802 volunteers (69.82 ± 5.60 years). The Fullerton Advanced Balance scale was used to assess balance and a composite score, including arm curl and chair stand tests for assessing MS. MM was estimated by dual-energy X-ray absorptiometry and physical activity by questionnaire. Results: Greater MM (r = .26, p < .001) and MS (r = .53, p < .001) were positively correlated to balance. The old-old adults and less active individuals attained lower balance. Notably, moderation and subsequent simple slope analyses revealed that the relations of balance, MM, and MS were larger in less active and the old-old adults. Conclusions: The old-old and less active adults were more prone to muscle weakness and balance impairments. Tailored interventions should particularly consider these vulnerable groups.

Restricted access

Matti Hyvärinen, Sarianna Sipilä, Janne Kulmala, Harto Hakonen, Tuija H. Tammelin, Urho M. Kujala, Vuokko Kovanen and Eija K. Laakkonen

Purpose: To investigate the validity and test–retest reliability of a single seven-level scale physical activity assessment question (SR-PA L7) and its three-level categorization (SR-PA C3). Methods: The associations of SR-PA L7 and C3 with accelerometer-measured leisure-time physical activity (ACC-LTPA) and with the results of four different physical performance tests (6-min walk [n = 733], knee extension [n = 695], vertical jump [n = 731], and grip force [n = 780]) were investigated among women aged 47–55 years participating in the Estrogenic Regulation of Muscle Apoptosis study (n = 795). The reliability was studied using Spearman correlations with 4-month test–retest period (n = 152). Results: SR-PA L7 and C3 had low correlations with ACC-LTPA (r s = .105–.337). SR-PA L7, SR-PA C3, and ACC-LTPA explained comparable but small amount of variance of the physical performance test results. The reliability analysis provided moderate agreement (r s = .707 and .622 for SR-PA L7 and C3, respectively). Conclusions: SR-PA L7 and C3 demonstrated limited validity and reasonable repeatability.

Restricted access

Jonathan Leo Ng, Chris Button, Dave Collins, Susan Giblin and Gavin Kennedy

Validated assessment tools for movement competence typically involve the isolation and reproduction of specific movement forms, which arguably neglects individuals’ ability to combine and adapt movements to overcome constraints within a dynamic environment. A new movement assessment tool, the General Movement Competence Assessment (GMCA), was developed for this study using Microsoft Kinect. Movement competence of 83 children (36 boys and 47 girls), aged 8–10 years (9.06 ± 0.75 years) was measured using the GMCA. An exploratory approach was undertaken to examine the internal consistency reliability (McDonald’s omega coefficient) and factorial structure of the GMCA for the study sample. Factorial structure was determined using exploratory factor analysis by principal component analysis with varimax rotation. For the sample data, reliability for the GMCA games were acceptable (ω = 0.53–0.89) and indicated that combinations of movement attributes were measured by GMCA games. Factorial analysis extracted four movement constructs accounting for 71.31% of variance. Dexterity was tentatively identified as a new independent construct alongside currently accepted movement constructs (i.e., locomotion, object-control, stability). While further development of the GMCA is still required, initial results are encouraging in view of an objective and theoretically informed approach to assess general movement competence in children.

Restricted access

Llion A. Roberts, Johnpaul Caia, Lachlan P. James, Tannath J. Scott and Vincent G. Kelly

Purpose: External counterpulsation (ECP) has previously been used to treat cardiac patients via compression of the lower extremities during diastole to increase venous return and coronary perfusion. However, the effects of ECP on exercise performance and markers of recovery in elite athletes are largely unknown. Methods: On 2 separate occasions, 48 h apart, 7 elite National Rugby League players performed an identical 60-min field-based conditioning session followed by a 30-min period of either regular ECP treatment or placebo. Power measures during repeated cycle bouts and countermovement jump height and contraction time derivatives were measured at rest and 5 h postexercise. Saliva samples and venous blood samples were taken at rest, postexercise, and 5 h postexercise to assess stress, inflammation, and muscle damage. Results: After ECP treatment, cycling peak power output (P = .028; 11%) and accumulated peak power (P = .027; 14%) increased compared with the placebo condition. Postexercise plasma interleukin 1 receptor antagonist only increased after ECP (P = .024; 84%), and concentrations of plasma interleukin 1 receptor antagonist tended to be higher (P = .093; 76%) 5 h postexercise. Furthermore, testosterone-to-cortisol ratio was increased above baseline and placebo 5 h postexercise (P = .017–.029; 24–77%). The ratio of postexercise salivary α-amylase to immunoglobulin A decreased after treatment (P = .013; 50%) compared with the placebo control. Conclusions: Exercise performance and hormonal indicators of stress were improved and inflammation markers were reduced following acute ECP.

Restricted access

Leeann M. Lower-Hoppe, Liz A. Wanless, Sarah M. Aldridge and Daniel W. Jones

Experiential learning is a critical component of sport management education and industry preparation; however, the inclusion of time-intensive experiential projects can displace content learning. Blended learning integrates face-to-face and online instruction to enable the space to maximize multiple learning types. This article proposes an innovative experiential project that integrates blended learning—implemented in a sport event management course—with reflection and scholarship supporting the pedagogical strategies. The article concludes with implications to optimize blended learning (e.g., multimedia, pedagogical workshops, course evaluation), enhance communication (e.g., office hours, discussion forum, orientation video), and expand student learning outcomes (e.g., reading outlines, video lectures, student assessment).

Restricted access

Thilo Kunkel, Rui Biscaia, Akiko Arai and Kwame Agyemang

This research explored the role of athlete on- and off-field brand image on consumer commitment toward the athlete and associated team, preference by the athlete’s sponsor, and the mediating effect of consumers’ self-brand connection on these relationships. Data were collected from fans of soccer players through a cross-sectional survey promoted on social media platforms. A partial least squares structural equation model examined the direct effects of both athlete brand dimensions on athlete commitment, team commitment, and athlete sponsor preference, and the indirect effects mediated via self-brand connection. The results indicate that an athlete’s on-field image is significantly related to athlete sponsor preference, while the off-field image influences athlete commitment and team commitment. Self-brand connection is influenced by athlete off-field image and mediates the relationship between off-field image and athlete commitment. This study contributes to a better understanding of how to manage athlete brands and linkages between fans, athletes, and associated entities.

Restricted access

Aaron T. Scanlan, Robert Stanton, Charli Sargent, Cody O’Grady, Michele Lastella and Jordan L. Fox

Purpose: To quantify and compare internal and external workloads in regular and overtime games and examine changes in relative workloads during overtime compared with other periods in overtime games in male basketball players. Methods: Starting players for a semiprofessional male basketball team were monitored during 2 overtime games and 2 regular games (nonovertime) with similar contextual factors. Internal (rating of perceived exertion and heart-rate variables) and external (PlayerLoad and inertial movement analysis variables) workloads were quantified across games. Separate linear mixed-models and effect-size analyses were used to quantify differences in variables between regular and overtime games and between game periods in overtime games. Results: Session rating-of-perceived-exertion workload (P = .002, effect size 2.36, very large), heart-rate workload (P = .12, 1.13, moderate), low-intensity change-of-direction events to the left (P = .19, 0.95, moderate), medium-intensity accelerations (P = .12, 1.01, moderate), and medium-intensity change-of-direction events to the left (P = .10, 1.06, moderate) were higher during overtime games than during regular games. Overtime periods also exhibited reductions in relative PlayerLoad (first quarter P = .03, −1.46, large), low-intensity accelerations (first quarter P = .01, −1.45, large; second quarter P = .15, −1.22, large), and medium-intensity accelerations (first quarter P = .09, −1.32, large) compared with earlier periods. Conclusions: Overtime games disproportionately elevate perceptual, physiological, and acceleration workloads compared with regular games in starting basketball players. Players also perform at lower external intensities during overtime periods than earlier quarters during basketball games.

Restricted access

Sandro Venier, Jozo Grgic and Pavle Mikulic

Purpose: To explore the acute effects of caffeinated chewing gum on vertical-jump performance, isokinetic knee-extension/flexion strength and power, barbell velocity in resistance exercise, and whole-body power. Methods: Nineteen resistance-trained men consumed, in randomized counterbalanced order, either caffeinated chewing gum (300 mg of caffeine) or placebo and completed exercise testing that included squat jump; countermovement jump; isokinetic knee extension and knee flexion at angular velocities of 60 and 180°·s−1; bench-press exercise with loads corresponding to 50%, 75%, and 90% of 1-repetition maximum (1RM); and an “all-out” rowing-ergometer test. Results: Compared with placebo, caffeinated chewing gum enhanced (all Ps < .05) (1) vertical-jump height in the squat jump (effect size [ES] = 0.21; +3.7%) and countermovement jump (ES = 0.27; +4.6%); (2) knee-extension peak torque (ES = 0.21; +3.6%) and average power (ES = 0.25; +4.5%) at 60°·s−1 and knee-extension average power (ES = 0.30; +5.2%) at 180°·s−1, and knee-flexion peak torque at 60°·s−1 (ES = 0.22; +4.1%) and 180°·s−1 (ES = 0.31; +5.9%); (3) barbell velocity at 50% of 1RM (ES = 0.30; +3.2%), 75% of 1RM (ES = 0.44; +5.7%), and 90% of 1RM (ES = 0.43; +9.1%); and (4) whole-body peak power on the rowing-ergometer test (ES = 0.41; +5.0%). Average power of the knee flexors did not change at either angular velocity with caffeine consumption. Conclusions: Caffeinated chewing gum with a dose of caffeine of 300 mg consumed 10 min preexercise may acutely enhance vertical-jump height, isokinetic strength and power of the lower-body musculature, barbell velocity in the bench-press exercise with moderate to high loads, and whole-body power.