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Alannah K.A. McKay, Peter Peeling, David B. Pyne, Nicolin Tee, Marijke Welveart, Ida A. Heikura, Avish P. Sharma, Jamie Whitfield, Megan L. Ross, Rachel P.L. van Swelm, Coby M. Laarakkers, and Louise M. Burke

This study implemented a 2-week high carbohydrate (CHO) diet intended to maximize CHO oxidation rates and examined the iron-regulatory response to a 26-km race walking effort. Twenty international-level, male race walkers were assigned to either a novel high CHO diet (MAX = 10 g/kg body mass CHO daily) inclusive of gut-training strategies, or a moderate CHO control diet (CON = 6 g/kg body mass CHO daily) for a 2-week training period. The athletes completed a 26-km race walking test protocol before and after the dietary intervention. Venous blood samples were collected pre-, post-, and 3 hr postexercise and measured for serum ferritin, interleukin-6, and hepcidin-25 concentrations. Similar decreases in serum ferritin (17–23%) occurred postintervention in MAX and CON. At the baseline, CON had a greater postexercise increase in interleukin-6 levels after 26 km of walking (20.1-fold, 95% CI [9.2, 35.7]) compared with MAX (10.2-fold, 95% CI [3.7, 18.7]). A similar finding was evident for hepcidin levels 3 hr postexercise (CON = 10.8-fold, 95% CI [4.8, 21.2]; MAX = 8.8-fold, 95% CI [3.9, 16.4]). Postintervention, there were no substantial differences in the interleukin-6 response (CON = 13.6-fold, 95% CI [9.2, 20.5]; MAX = 11.2-fold, 95% CI [6.5, 21.3]) or hepcidin levels (CON = 7.1-fold, 95% CI [2.1, 15.4]; MAX = 6.3-fold, 95% CI [1.8, 14.6]) between the dietary groups. Higher resting serum ferritin (p = .004) and hotter trial ambient temperatures (p = .014) were associated with greater hepcidin levels 3 hr postexercise. Very high CHO diets employed by endurance athletes to increase CHO oxidation have little impact on iron regulation in elite athletes. It appears that variations in serum ferritin concentration and ambient temperature, rather than dietary CHO, are associated with increased hepcidin concentrations 3 hr postexercise.

Open access
Open access

Peter Gelius, Antonina Tcymbal, Stephen Whiting, Sven Messing, Karim Abu-Omar, Wolfgang Geidl, Anne Kerstin Reimers, Klaus Pfeifer, Romeu Mendes, Nino Berdzuli, and Joao Breda

Background: The COVID-19 pandemic is a major challenge for societies and governments around the world that severely affects all aspects of health promotion. This study assesses the potential influence of the first wave of the pandemic on national physical activity promotion policy in the European Union (EU). Methods: Data were collected using an online survey among members of the EU Physical Activity Focal Point Network, which consists of government officials from all EU member states. Results: The COVID-19 pandemic has significantly affected physical activity promotion across the EU. In particular, experts indicated that it has negatively impacted opportunities for physical activity in their countries. There have, however, been positive effects of the crisis on public awareness of physical activity. While almost all countries were able to issue physical activity recommendations during quarantine, opinions varied regarding the overall impact of the pandemic on governmental capacities for physical activity promotion and policy. Conclusions: This study shows that the COVID-19 crisis has had both negative and positive effects on physical activity promotion in the EU. The positive experiences reported by some members of the Focal Point Network may assist other countries in identifying potential policy windows and strategies for the ongoing pandemic.

Open access

Oliver C. Witard, Laurent Bannock, and Kevin D. Tipton

The acute response of muscle protein synthesis (MPS) to resistance exercise and nutrition is often used to inform recommendations for exercise programming and dietary interventions, particularly protein nutrition, to support and enhance muscle growth with training. Those recommendations are worthwhile only if there is a predictive relationship between the acute response of MPS and subsequent muscle hypertrophy during resistance exercise training. The metabolic basis for muscle hypertrophy is the dynamic balance between the synthesis and degradation of myofibrillar proteins in muscle. There is ample evidence that the process of MPS is much more responsive to exercise and nutrition interventions than muscle protein breakdown. Thus, it is intuitively satisfying to translate the acute changes in MPS to muscle hypertrophy with training over a longer time frame. Our aim is to examine and critically evaluate the strength and nature of this relationship. Moreover, we examine the methodological and physiological factors related to measurement of MPS and changes in muscle hypertrophy that contribute to uncertainty regarding this relationship. Finally, we attempt to offer recommendations for practical and contextually relevant application of the information available from studies of the acute response of MPS to optimize muscle hypertrophy with training.

Open access

Jacqueline L. Mair, Lawrence D. Hayes, Amy K. Campbell, and Nicholas Sculthorpe

Researchers, practitioners, and public health organizations from around the world are becoming increasingly interested in using data from consumer-grade devices such as smartphones and wearable activity trackers to measure physical activity (PA). Indeed, large-scale, easily accessible, and autonomous data collection concerning PA as well as other health behaviors is becoming ever more attractive. There are several benefits of using consumer-grade devices to collect PA data including the ability to obtain big data, retrospectively as well as prospectively, and to understand individual-level PA patterns over time and in response to natural events. However, there are challenges related to representativeness, data access, and proprietary algorithms that, at present, limit the utility of this data in understanding population-level PA. In this brief report we aim to highlight the benefits, as well as the limitations, of using existing data from smartphones and wearable activity trackers to understand large-scale PA patterns and stimulate discussion among the scientific community on what the future holds with respect to PA measurement and surveillance.

Open access

Kobe C. Houtmeyers, Arne Jaspers, and Pedro Figueiredo

Elite sport practitioners increasingly use data to support training process decisions related to athletes’ health and performance. A careful application of data analytics is essential to gain valuable insights and recommendations that can guide decision making. In business organizations, data analytics are developed based on conceptual data analytics frameworks. The translation of such a framework to elite sport may benefit the use of data to support training process decisions. Purpose: The authors aim to present and discuss a conceptual data analytics framework, based on a taxonomy used in business analytics literature to help develop data analytics within elite sport organizations. Conclusions: The presented framework consists of 4 analytical steps structured by value and difficulty/complexity. While descriptive (step 1) and diagnostic analytics (step 2) focus on understanding the past training process, predictive (step 3) and prescriptive analytics (step 4) provide more guidance in planning the future. Although descriptive, diagnostic, and predictive analytics generate insights to inform decisions, prescriptive analytics can be used to drive decisions. However, the application of this type of advanced analytics is still challenging in elite sport. Thus, the current use of data in elite sport is more focused on informing decisions rather than driving them. The presented conceptual framework may help practitioners develop their analytical reasoning by providing new insights and guidance and may stimulate future collaborations between practitioners, researchers, and analytics experts.

Open access

Philip Friere Skiba and David C. Clarke

Since its publication in 2012, the W′ balance model has become an important tool in the scientific armamentarium for understanding and predicting human physiology and performance during high-intensity intermittent exercise. Indeed, publications featuring the model are accumulating, and it has been adapted for popular use both in desktop computer software and on wrist-worn devices. Despite the model’s intuitive appeal, it has achieved mixed results thus far, in part due to a lack of clarity in its basis and calculation. Purpose: This review examines the theoretical basis, assumptions, calculation methods, and the strengths and limitations of the integral and differential forms of the W′ balance model. In particular, the authors emphasize that the formulations are based on distinct assumptions about the depletion and reconstitution of W′ during intermittent exercise; understanding the distinctions between the 2 forms will enable practitioners to correctly implement the models and interpret their results. The authors then discuss foundational issues affecting the validity and utility of the model, followed by evaluating potential modifications and suggesting avenues for further research. Conclusions: The W′ balance model has served as a valuable conceptual and computational tool. Improved versions may better predict performance and further advance the physiology of high-intensity intermittent exercise.

Open access

Katja Siefken, Andrea Ramirez Varela, Temo Waqanivalu, and Nico Schulenkorf

Since 2020, the world has been navigating an epidemiologic transition with both infectious diseases (COVID-19) and noncommunicable diseases intertwined in complex and diverse ways. In fact, the pandemics of physical inactivity, noncommunicable diseases, and COVID-19 coincide in a tragically impactful ménage à trois with their detrimental long-term health consequences yet to be determined. We know that people in low- and middle-income countries not only have the highest risk of developing chronic diseases, they also develop the diseases at a younger age, they suffer longer, and they die earlier than people in high-income countries. This commentary features 5 compelling reasons for putting physical activity in low- and middle-income countries high up on the public health research agenda and calls for more commitment to inclusive and context-specific public health practices that are paired with locally relevant promotion and facilitation of PA practice, research, and policymaking.