Maureen R. Weiss
Vasilios Armatas, Eleni Bassa, Dimitrios Patikas, Ilias Kitsas, Georgios Zangelidis and Christos Kotzamanidis
The aim of this study was to examine the fatigue and recovery in boys and men during a maximal intermittent isometric fatigue test of the knee extensor muscles, by evaluating the electromyogram of vastus lateralis, vastus medialis and biceps femoris. Thirteen boys (10.0 ± 0.8yrs) and 13 men (26.1 ± 4.2yrs) were fatigued until torque reached 50% of its initial value. Three and 6 min after, a maximal isometric knee extension test was assessed. Men had faster torque decline during fatigue and slower torque recovery compared with boys. Agonist activity declined in both groups during fatigue but men had greater extent of reduction. After 6 min boys recovered fully in respect to agonist EMG, whereas this was not the case for the men. The lower level of fatigue and faster recovery in boys could be attributed to the limited inhibition that was observed in the boys’ agonist muscles, whereas the antagonist activity does not seem to play a role in the fatigue or recovery differences between the groups.
Tara K. Scanlan, David G. Russell, Larry A. Scanlan, Tatiana J. Klunchoo and Graig M. Chow
Following a thorough review of the current updated Sport Commitment Model, new candidate commitment sources for possible future inclusion in the model are presented. They were derived from data obtained using the Scanlan Collaborative Interview Method. Three elite New Zealand teams participated: amateur All Black rugby players, amateur Silver Fern netball players, and professional All Black rugby players. An inductive content analysis of these players’ open-ended descriptions of their sources of commitment identified four unique new candidate commitment sources: Desire to Excel, Team Tradition, Elite Team Membership, and Worthy of Team Membership. A detailed definition of each candidate source is included along with example quotes from participants. Using a mixed-methods approach, these candidate sources provide a basis for future investigations to test their viability and generalizability for possible expansion of the Sport Commitment Model.
Daniela A. Rubin, Robert G. McMurray and Joanne S. Harrell
Differences in insulin concentrations between normal weight or overweight adolescents (n = 437) were determined depending on their habitual physical activity (PA) and aerobic power (pVO2max). Tertiles were computed for PA (survey) and pVO2max (submaximal predicted cycle test). Independent of their weight, adolescents in the upper 2 tertiles for vigorous PA had lower insulin concentrations than those in the bottom tertile (p < .05). Adolescents in the top tertile for pVO2max expressed per kg fat-free mass also had lower insulin concentrations than those in the medium and bottom tertiles (p = .002). In youth, vigorous physical activity and aerobic power are associated with fasting insulin independent of weight status.
Tara K. Scanlan, David G. Russell, T. Michelle Magyar and Larry A. Scanlan
The Sport Commitment Model was further tested using the Scanlan Collaborative Interview Method to examine its generalizability to New Zealand’s elite female amateur netball team, the Silver Ferns. Results supported or clarified Sport Commitment Model predictions, revealed avenues for model expansion, and elucidated the functions of perceived competence and enjoyment in the commitment process. A comparison and contrast of the in-depth interview data from the Silver Ferns with previous interview data from a comparable elite team of amateur male athletes allowed assessment of model external validity, tested the generalizability of the underlying mechanisms, and separated gender differences from discrepancies that simply reflected team or idiosyncratic differences.
Tara K. Scanlan, David G. Russell, Kristin P. Beals and Larry A. Scanlan
Prospective interview data obtained using the Scanlan Collaborative Interview Method (Scanlan, Russell, Wilson, & Scanlan, 2003) allow further testing and expansion of the Sport Commitment Model (Scanlan, Carpenter, Schmidt, Simons, & Keeler, 1993) and provide a deeper understanding of the commitment process. We examine the Model constructs of Sport Enjoyment, Involvement Opportunities, Involvement Alternatives, Personal Investments, Social Constraints, and a potential new construct, Social Support, to understand how and under what conditions each of the constructs operates. The data from 15 New Zealand All Black rugby players support the Model predictions, show its generalizability from American youth sport to amateur elite-level New Zealand athletes, and suggest possible Model expansion and modification.