Zhen Zeng, Christoph Centner, Albert Gollhofer and Daniel König
Purpose: Setting the optimal cuff pressure is a crucial part of prescribing blood-flow-restriction training. It is currently recommended to use percentages of each individual’s arterial occlusion pressure, which is most accurately determined by Doppler ultrasound (DU). However, the practicality of this gold-standard method in daily training routine is limited due to high costs. An alternative solution is pulse oximetry (PO). The main purpose of this study was to evaluate validity between PO and DU measurements and to investigate whether sex has a potential influence on these variables. Methods: A total of 94 subjects were enrolled in the study. Participants were positioned in a supine position, and a 12-cm-wide cuff was applied in a counterbalanced order at the most proximal portion of the right upper and lower limbs. The cuff pressure was successively increased until pulse was no longer detected by DU and PO. Results: There were no significant differences between the DU and PO methods when measuring arterial occlusion pressure at the upper limb (P = .308). However, both methods showed considerable disagreement for the lower limbs (P = .001), which was evident in both men (P = .028) and women (P = .008). No sex differences were detected. Conclusions: PO is reasonably accurate to determine arterial occlusion pressure of the upper limbs. For lower limbs, PO does not seem to be a valid instrument when assessing the optimal cuff pressure for blood-flow-restriction interventions compared with DU.
Øyvind Skattebo, Thomas Losnegard and Hans Kristian Stadheim
Purpose: Long-distance cross-country skiers specialize to compete in races >50 km predominantly using double poling (DP). This emphasizes the need for highly developed upper-body endurance capacities and an efficient DP technique. The aim of this study was to investigate potential effects of specialization by comparing physiological capacities and kinematics in DP between long-distance skiers and skiers competing using both techniques (skating/classic) in several competition formats (“all-round skiers”). Methods: Seven male long-distance (32  y, 183  cm, 76  kg) and 6 all-round (25  y, 181  cm, 75  kg) skiers at high international levels conducted submaximal workloads and an incremental test to exhaustion for determination of peak oxygen uptake (VO2peak) and time to exhaustion (TTE) in DP and running. Results: In DP and running maximal tests, TTE showed no difference between groups. However, long-distance skiers had 5–6% lower VO2peak in running (81  vs 85  mL·kg−1·min−1; P = .07) and DP (73  vs 78  mL·kg−1·min−1; P < .01) than all-round skiers. In DP, long-distance skiers displayed lower submaximal O2 cost than all-round skiers (3.8 ± 3.6%; P < .05) without any major differences in cycle times or cyclic patterns of joint angles and center of mass. Lactate concentration over a wide range of speeds (45–85% of VO2peak) did not differ between groups, even though each workload corresponded to a slightly higher percentage of VO2peak for long-distance skiers (effect size: 0.30–0.68). Conclusions: The long-distance skiers displayed lower VO2peak but compensated with lower O2 cost to perform equally with the all-round skiers on a short TTE test in DP. Furthermore, similar submaximal lactate concentration and reduced O2 cost could be beneficial in sustaining high skiing speeds in long-duration competitions.
Hedda Berntsen and Elsa Kristiansen
The purpose of this article is to share the conceptual framework, design, and impact evidence of a coach development program that was aimed at teaching coaches how to act need-supportive toward their athletes. Informed by Self-Determination Theory, the Motivation Activation Program in Sports (MAPS) was developed to contribute a coach interpersonal-style perspective to the Norwegian Ski Federation education system. The program was delivered at the Norwegian College of Elite Sport throughout the 2016/2017 season as a test trial. This article is organized into three sections. First, a detailed description of the conceptual framework used to inform MAPS is offered. Next, a thorough description of MAPS building components is provided. The third section of the article presents impact evidence of coaches’ learning experiences together with coaches’ practice examples of need-supportive coaching skills. Results reveal that MAPS taught coaches about need-supportive skills at the intrapersonal (awareness of own coaching practice) and interpersonal (interaction with athletes) level. In addition, effective need-support for athletes required sufficient time for each athlete, a gradual approach to athlete understanding, and a thorough consideration of specific situations.
Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee and Song-Young Park
Purpose: Athletes in combat sports undergo rapid changes in body weight prior to competition in order to gain a size advantage over their opponent. However, these large weight changes with concomitant high-intensity exercise training create poor lipid profiles and high levels of oxidative stress, which can be detrimental to health and sport performance. Therefore, the purpose of this study was to investigate the ability of the nutritional supplement octacosanol to combat the physiological detriments that occur in taekwondo players during rapid weight loss with high-intensity exercise training. Methods: A total of 26 male taekwondo players were randomly divided into 2 groups: An experimental group performed a 5% weight-loss and taekwondo training program with 40-mg octacosanol intake (OCT; n = 13) for 6 d, and a control group performed the same weight-loss and taekwondo training program with a placebo (CON; n = 13). Results: There were significant (P < .05) group × time interactions for low-density lipoprotein and triglycerides, which significantly decreased (Δ18  mg/dL and Δ80  mg/dL, respectively), and high-density lipoprotein, which significantly increased (Δ10  mg/dL), in the OCT group compared with the CON group. There were also significant (P < .05) group × time interactions for superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA), with SOD increasing (Δ226  U/gHb) in the OCT group, while GPx decreased (Δ20  U/gHb) and MDA increased (Δ72 [0.04] nmol/mL) in the CON group. Conclusion: These results suggest that octacosanol may be a beneficial supplement to protect against the poor cholesterol levels and oxidative stress that occurs during taekwondo training.
Carlos Capella-Peris, Jesús Gil-Gómez and Òscar Chiva-Bartoll
Purpose: To compare the development of teaching competency in preservice teachers of physical education (n = 96) through two different modalities of intervention from the same service-learning program. The preservice teachers provided a direct service to children with motor functional diversity, promoting their motor skills and counteracting their lack of social attention. Method: The topic was approached using mixed methods with methodological triangulation. Quantitative evidence was gathered through a quasi-experimental design of two nonequivalent experimental groups implementing the following instrument: the Teaching Competency while performing Motor Skills and Body Language Games Rubric. Meanwhile, qualitative analysis was undertaken by elaborating upon 12 life histories of multiple crossed stories. Results: The quantitative results provided significant evidence regarding the academic effect of service-learning on preservice teachers, while the qualitative interpretation complemented this view, reflecting on how this learning was developed. Discussion/Conclusion: The authors provided the original findings of the service-learning effects on the teaching competency of preservice teachers as well as the promotion of additional academic and social learning.
Terese Wilhelmsen, Marit Sørensen and Ørnulf N. Seippel
This article is focused on how combinations of motivational attributes and motivational climates support social and pedagogical inclusion in physical education among children with disabilities. Theoretically, the authors integrate tenets from achievement-goal theory and self-determination theory. To capture the motivational complexity underlying children’s experiences of inclusion in physical education, they use a 2-step fuzzy qualitative comparative analysis. The analyses of contextual conditions yielded 2 sufficient inclusion-supportive climates, namely a physically inclusive and mastery-oriented climate or a physical inclusive, autonomy-supportive, and low performance-oriented climate. The configurations of motivational attributes in the inclusion-supportive climates indicated 4 sufficient pathways to social and pedagogical inclusion. The path with the largest coverage of children was in the physically inclusive and mastery-oriented climate and represented children who were task and ego oriented and low on amotivation and experienced satisfaction of the need for autonomy, competence, and relatedness.
Michael Kellmann, Maurizio Bertollo, Laurent Bosquet, Michel Brink, Aaron J. Coutts, Rob Duffield, Daniel Erlacher, Shona L. Halson, Anne Hecksteden, Jahan Heidari, K. Wolfgang Kallus, Romain Meeusen, Iñigo Mujika, Claudio Robazza, Sabrina Skorski, Ranel Venter and Jürgen Beckmann
The relationship between recovery and fatigue and its impact on performance has attracted the interest of sport science for many years. An adequate balance between stress (training and competition load, other life demands) and recovery is essential for athletes to achieve continuous high-level performance. Research has focused on the examination of physiological and psychological recovery strategies to compensate external and internal training and competition loads. A systematic monitoring of recovery and the subsequent implementation of recovery routines aims at maximizing performance and preventing negative developments such as underrecovery, nonfunctional overreaching, the overtraining syndrome, injuries, or illnesses. Due to the inter- and intraindividual variability of responses to training, competition, and recovery strategies, a diverse set of expertise is required to address the multifaceted phenomena of recovery, performance, and their interactions to transfer knowledge from sport science to sport practice. For this purpose, a symposium on Recovery and Performance was organized at the Technical University Munich Science and Study Center Raitenhaslach (Germany) in September 2016. Various international experts from many disciplines and research areas gathered to discuss and share their knowledge of recovery for performance enhancement in a variety of settings. The results of this meeting are outlined in this consensus statement that provides central definitions, theoretical frameworks, and practical implications as a synopsis of the current knowledge of recovery and performance. While our understanding of the complex relationship between recovery and performance has significantly increased through research, some important issues for future investigations are also elaborated.