The long-standing caffeine habituation paradigm was never investigated in strength endurance and jumping exercise performance through a straightforward methodology. The authors examined if habitual caffeine consumption would influence the caffeine ergogenic effects on strength endurance and jumping performance as well as perceptual responses. Thirty-six strength-trained individuals were mathematically allocated into tertiles according to their habitual caffeine consumption: low (20 ± 11 mg/day), moderate (88 ± 33 mg/day), and high consumers (281 ± 167 mg/day). Then, in a double-blind, crossover, counterbalanced fashion, they performed a countermovement vertical jump test and a strength endurance test either after caffeine (6 mg/kg) and placebo supplementation or after no supplementation (control). Perceptual responses such as ratings of perceived exertion and pain were measured at the termination of the exercises. Acute caffeine supplementation improved countermovement vertical jump performance (p = .001) and total repetitions (p = .004), regardless of caffeine habituation. Accordingly, analysis of absolute change from the control session showed that caffeine promoted a significantly greater improvement in both countermovement vertical jump performance (p = .004) and total repetitions (p = .0001) compared with placebo. Caffeine did not affect the rating of perceived exertion and pain in any exercise tests, irrespective of tertiles (for all comparisons, p > .05 for both measures). Caffeine side effects were similar in low, moderate, and high caffeine consumers. These results show that habitual caffeine consumption does not influence the potential of caffeine as an ergogenic aid in strength endurance and jumping exercise performance, thus challenging recommendations to withdraw from the habitual caffeine consumption before supplementing with caffeine.
Vitor de Salles Painelli, Emerson L. Teixeira, Bruno Tardone, Marina Moreno, Jonatas Morandini, Victória H. Larrain, and Flávio O. Pires
Bruno Ruiz Brandão da Costa, Rafaela Rocha Roiffé, and Márcia Nogueira da Silva de la Cruz
The growing consumer awareness regarding health and fitness has been leading to a huge rise in the consumption of nutritional supplements and, consequently, to an increase in concerns about their quality. In this sense, one of the most consumed products is protein supplements and, despite being safer than other types of supplements, there are several studies showing incompatibilities between what is present on the labels and their actual content. Therefore, this review is focused on gathering information about the problems arising from poor manufacturing practices and inadequate quality control of sport protein supplements. These issues are mainly related to three aspects: reduction of the supplements’ nutritional value, the presence of pharmacological substances, and contamination with microorganisms or toxic metals. Regarding the first aspect, reports about the “classic” addition of nitrogen-rich compounds to mask the protein content measured by the Kjeldahl method were discussed, as well as recent topics such as the addition of cheaper proteins to produce an “undetectable” adulteration in whey protein supplements. With respect to the presence of pharmacological compounds, it is a finding that is not very common in protein supplements; however, even trace amounts of foreign substances in this type of product may cause adverse effects to consumers, and, in the case of an elite athlete, may result in doping. Finally, we discuss about the contamination with microorganisms and toxic metals, this latter being a subject that should be further explored due to few studies in the literature.
Lambros Lazuras, Vassilis Barkoukis, Dmitriy Bondarev, Yannis Ntovolis, Konstantin Bochaver, Nikolaos Theodorou, and Kevin Bingham
Whistleblowing against doping misconduct represents an effective deterrent of doping use in elite competitive sport. The present study assessed the effects of social cognitive variables on competitive athletes’ intentions to report doping misconduct. A second objective was to assess whether the effects of social norms on whistleblowing intentions were mediated by actor prototype evaluations and group identification and orientation. In total, 1,163 competitive athletes from Greece, Russia, and the United Kingdom completed a questionnaire on demographics, past behavior, social cognitive variables, and intentions toward whistleblowing. Regression analyses showed that whistleblowing intentions were associated with different social cognitive variables in each country. Multiple mediation modeling showed that attitudes and subjective norms were associated with whistleblowing intentions indirectly, via the effects of anticipated negative affect and group identification and orientation, respectively. The findings of this study are novel and have important implications about the social, cognitive, and normative processes underlying decision making toward reporting doping misconduct.
Lenore Dedeyne, Jorgen A. Wullems, Jolan Dupont, Jos Tournoy, Evelien Gielen, and Sabine Verschueren
Tools for objective monitoring of home-based training and physical behavior (PB) in (pre)sarcopenic older adults are needed. The present study explored two approaches with machine learning models, including accelerometer data either with or without additional gyroscope data (in an inertial measurement unit). Twenty-five community-dwelling (pre)sarcopenic adults mean 80.7 [5.5] years) performed the Otago exercise protocol (OEP) and PB modules (e.g., sitting or walking) while wearing an inertial measurement unit on the lower back (Dynaport MoveMonitor; McRoberts, The Hague, The Netherlands). Machine learning (ML) models for classification were developed by two approaches (top-down and bottom-up approaches) and with two levels of classification: general (no wear, OEP, and PB) and detailed (all subclassifications). Classification output was compared with video recordings. For the bottom-up approach, one ML model was developed. For the top-down approach, data were first classified as no wear, OEP, or PB. Thereafter, OEP and PB were subclassified by one ML model each into subclassification. Only classification of the general classification no wear and the subclassification sitting/lying reached the acceptable performance threshold of 80%. This result was independent of the approach used. Moreover, a gyroscope did not improve performance. Despite the progress in ML techniques and monitors, objective compliance registrations remain challenging.
Stijn V. Mentzel, Bjoern Krenn, Dennis Dreiskaemper, and Bernd Strauss
This study examines the influence of wearing and perceiving colors in a cycling setting while also examining cortisol, heart rate, estimated maximum oxygen consumption, and subjective performance ratings. A total of 99 individuals completed the study, consisting of cortisol measurements, which compared baseline values to those after changing into a red or blue outfit, and a maximum cycling task performed wearing the same outfit while competing against a video opponent in red or blue. Each participant completed the protocol twice on separate days. Wearing a colored outfit showed no influence on cortisol levels. Regarding the cycling task, the participants wearing red had higher maximum heart rate values than when wearing blue. In addition, the results revealed increased maximum heart rate and maximum oxygen consumption values when perceiving an opponent in blue, especially when the participant also wore blue. No differences were found for the median heart rate or performance ratings.
Edgar Schwarz, Liam D. Harper, Rob Duffield, Robert McCunn, Andrew Govus, Sabrina Skorski, and Hugh H.K. Fullagar
Purpose: To examine practitioners’, coaches’, and athletes’ perceptions of evidence-based practice (EBP) in professional sport in Australia. Methods: One hundred thirty-eight participants (practitioners n = 67, coaches n = 39, and athletes n = 32) in various professional sports in Australia each completed a group-specific online questionnaire. Questions focused on perceptions of research, the contribution of participants’ own experience in implementing knowledge to practice, sources, and barriers for accessing and implementing EBP, preferred methods of feedback, and the required qualities of practitioners. Results: All practitioners reported using EBP, while most coaches and athletes believed that EBP contributes to individual performance and preparation (>85%). Practitioners’ preferred EBP information sources were “peer-reviewed journals” and “other practitioners within their sport,” while athlete sources were “practitioners within their sport” and “other athletes within their sport.” As primary barriers to accessing and implementing research, practitioners highlighted “time constraints,” “poor research translation,” and “nonapplicable research.” Practitioners ranked “informal conversation” as their most valued method of providing feedback; however, coaches prefer feedback from “scheduled meetings,” “online reports,” or “shared database.” Both athletes and coaches value “excellent knowledge of the sport,” “experience,” and “communication skills” in practitioners disseminating EBP. Conclusion: Practitioners, coaches, and athletes believe in the importance of EBP to their profession, although practitioners reported several barriers to accessing and implementing research as part of EBP. Athletes place a high value on experienced practitioners who have excellent knowledge of the sport and communication skills. Collectively, these findings can be used to further stakeholder understanding regarding EBP and the role of research to positively influence athlete health.
Karen Milton, Nick Cavill, Anna Chalkley, Charlie Foster, Sjaan Gomersall, Maria Hagstromer, Paul Kelly, Tracy Kolbe-Alexander, Jacqueline Mair, Matthew McLaughlin, James Nobles, Lindsey Reece, Trevor Shilton, Ben J. Smith, and Jasper Schipperijn
Background: The International Society for Physical Activity and Health (ISPAH) is a leading global organization working to advance research, policy, and practice to promote physical activity. Given the expanding evidence base on interventions to promote physical activity, it was timely to review and update a major ISPAH advocacy document—Investments that Work for Physical Activity (2011). Methods: Eight investment areas were agreed upon through consensus. Literature reviews were conducted to identify key evidence relevant to policymakers in each sector or setting. Results: The 8 investment areas were as follows: whole-of-school programs; active transport; active urban design; health care; public education; sport and recreation; workplaces; and community-wide programs. Evidence suggests that the largest population health benefit will be achieved by combining these investments and implementing a systems-based approach. Conclusions: Establishing consensus on ‘what works’ to change physical activity behavior is a cornerstone of successful advocacy, as is having appropriate resources to communicate key messages to a wide range of stakeholders. ISPAH has created a range of resources related to the new investments described in this paper. These resources are available in the ‘advocacy toolkit’ on the ISPAH website (www.ispah.org/resources).
Sebastien F.M. Chastin, Duncan E. McGregor, Stuart J.H. Biddle, Greet Cardon, Jean-Philippe Chaput, Philippa M. Dall, Paddy C. Dempsey, Loretta DiPietro, Ulf Ekelund, Peter T. Katzmarzyk, Michael Leitzmann, Emmanuel Stamatakis, and Hidde P. Van der Ploeg
Background: Crucial evidence gaps regarding: (1) the joint association of physical activity and sedentary time with health outcomes and (2) the benefits of light-intensity physical activity were identified during the development of recommendations for the World Health Organization Guidelines on physical activity and sedentary behavior (SB). The authors present alternative ways to evidence the relationship between health outcomes and time spent in physical activity and SB and examine how this could be translated into a combined recommendation in future guidelines. Methods: We used compositional data analysis to quantify the dose–response associations between the balance of time spent in physical activity and SB with all-cause mortality. The authors applied this approach using 2005–2006 National Health and Nutrition Examination Survey accelerometer data. Results: Different combinations of time spent in moderate- to vigorous-intensity physical activity, light-intensity physical activity, and SB are associated with similar all-cause mortality risk level. A balance of more than 2.5 minutes of moderate- to vigorous-intensity physical activity per hour of daily sedentary time is associated with the same magnitude of risk reduction for all-cause mortality as obtained by being physically active according to the current recommendations. Conclusion: This method could be applied to provide evidence for more flexible recommendations in the future with options to act on different behaviors depending on individuals’ circumstances and capacity.
Leigh M. Vanderloo, Jonathan L. Maguire, Charles D.G. Keown-Stoneman, Patricia C. Parkin, Cornelia M. Borkhoff, Mark S. Tremblay, Laura N. Anderson, Catherine S. Birken, and on behalf of the TARGet Kids! Collaboration
Introduction: The authors aimed to examine the association between meeting the integrative movement behavior guidelines (physical activity, screen viewing, and sleep) and cardiometabolic risk (CMR) factors in young children. Methods: In this cross-sectional study, physical activity, screen viewing, and sleep were assessed using parent-reported data. The 24-Hour Movement Guidelines for the Early Years (0–4 y) were defined as 180 minutes of physical activity/day (of which ≥60 min should be moderate-to-vigorous intensity), ≤1 hour of screen viewing/day, and 10 to 13 hours of sleep/night. Waist circumference, glucose, high-density lipoprotein cholesterol, triglycerides, and systolic blood pressure were measured in a clinical setting by trained staff. A total CMR score and individual CMR factors served as primary and secondary outcomes, respectively. Results: Of the 767 participants (3–4 y), 26.4% met none of the guideline’s recommendations, whereas 41.3%, 33.1%, and 10.6% of the sample met 1, 2, or all 3 recommendations, respectively. The number of recommendations met was not associated with the total CMR score or individual CMR factors (P > .05), with the exceptions of high-density lipoprotein (odds ratio = 1.61; 95% confidence interval, 1.11 to 2.33; P = .01). Conclusion: Meeting the 24-Hour Movement Guidelines in early childhood was not associated with overall CMR, but was associated with favorable cholesterol outcomes.