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  • Author: Javier S. Morales x
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Acute Ketone Supplementation and Exercise Performance: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Pedro L. Valenzuela, Javier S. Morales, Adrián Castillo-García, and Alejandro Lucia

Purpose: To determine the acute effects of ketone supplementation on exercise performance (primary outcome) and physiological and perceptual responses to exercise (secondary outcomes). Methods: A systematic search was conducted in PubMed, Web of Science, and SPORTDiscus (since inception to July 21, 2019) to find randomized controlled trials assessing the effects of acute ketone supplementation compared with a drink containing no ketones (ie, control intervention). The standardized mean difference (Hedges g) between interventions and 95% confidence interval (CI) were computed using a random-effects model. Results: Thirteen studies met all inclusion criteria. No significant differences were observed between interventions for overall exercise performance (Hedges g = −0.05; 95% CI, −0.30 to 0.20; P = .68). Subanalyses revealed no differences between interventions when analyzing endurance time-trial performance (g = −0.04; 95% CI, −0.35 to 0.28; P = .82) or when assessing the separate effects of supplements containing ketone esters (g = −0.07; 95% CI, −0.38 to 0.24; P = .66) or salts (g = −0.02; 95% CI, −0.45 to 0.41; P = .93). All studies reported increases in plasma ketone concentration after acute ketone supplementation, but no consistent effects were reported on the metabolic (plasma lactate and glucose levels), respiratory (respiratory exchange ratio, oxygen uptake, and ventilatory rate), cardiovascular (heart rate), or perceptual responses to exercise (rating of perceived exertion). Conclusions: The present findings suggest that ketone supplementation exerts no clear influence on exercise performance (from sprints to events lasting up to ∼50 min) or metabolic, respiratory, cardiovascular, or perceptual responses to exercise. More research is needed to elucidate if this strategy could provide ergogenic effects on other exercise types (eg, ultraendurance exercise).

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Is the Functional Threshold Power a Valid Surrogate of the Lactate Threshold?

Pedro L. Valenzuela, Javier S. Morales, Carl Foster, Alejandro Lucia, and Pedro de la Villa

Purpose: To analyze the relationship between functional threshold power (FTP) and the lactate threshold (LT). Methods: A total of 20 male cyclists performed an incremental test in which LT was determined. At least 48 h later, they performed a 20-min time trial, and 95% of the mean power output was defined as FTP. Participants were divided into recreational (peak power output < 4.5 W·kg−1; n = 11) or trained cyclists (peak power output > 4.5 W·kg−1; n = 9) according to their fitness status. Results: The FTP (240 [35] W) was overall not significantly different (effect size = 0.20; limits of agreement = −2.4% [11.5%]) from the LT (246 [24] W), and both markers were strongly correlated (r = .95; P < .0001). Accounting for the participants’ fitness status, no significant differences were found between FTP and LT (effect size = 0.22; limits of agreement =2.1% [7.8%]) in trained cyclists, but FTP was significantly lower than the LT (P = .0004, effect size = 0.81; limits of agreement =−6.5% [8.3%]) in recreational cyclists. A significant relationship was found between relative peak power output and the bias between FTP and the LT markers (r = .77; P < .0001). Conclusions: FTP is a valid field test-based marker for the assessment of endurance fitness. However, caution should be taken when using FTP interchangeably with LT, as the bias between markers seems to depend on the athlete’s fitness status. Whereas FTP provides a good estimate of LT in trained cyclists, in recreational cyclists, it may underestimate LT.

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Ultraendurance Exercise in a Renal Transplant Recipient: A Case Study

Sonsoles Hernández-Sánchez, Pedro L. Valenzuela, Javier S. Morales, Juan J. Carrero, Alejandro Lucia, and Jonatan R. Ruiz

Context: Exercise improves the commonly impaired physical fitness and cardiovascular health of transplant recipients. However, concerns remain about the safety of strenuous physical exercise in this population. Purpose: To describe the physiological effects of ultraendurance exercise in a renal transplant recipient. Methods: After a 25-week training program, a 31-year-old male with stage 3 chronic kidney disease who had undergone 2 kidney transplants participated in a 62-km (5600 m of positive altitude change) trail-running race. Blood and urine analyses were performed at baseline (24 h before the race), 4 days after the race, and at different time points up to 16 weeks postexercise. Results: The participant completed the race in 12 hours 18 minutes. No noticeable side effects were recorded during the whole study period, including the prerace training program. No major urine or blood alterations were observed after ultraendurance exercise, with glomerular filtration rate remaining steady during the study period. Conclusions: Ultraendurance exercise induced no adverse physiological effects in a well-trained young renal transplant recipient.

Open access

Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity—GoPA! 2015 and 2020 Surveys

Andrea Ramírez Varela, Pedro C. Hallal, Juliana Mejía Grueso, Željko Pedišić, Deborah Salvo, Anita Nguyen, Bojana Klepac, Adrian Bauman, Katja Siefken, Erica Hinckson, Adewale L. Oyeyemi, Justin Richards, Elena Daniela Salih Khidir, Shigeru Inoue, Shiho Amagasa, Alejandra Jauregui, Marcelo Cozzensa da Silva, I-Min Lee, Melody Ding, Harold W. Kohl III, Ulf Ekelund, Gregory W. Heath, Kenneth E. Powell, Charlie Foster, Aamir Raoof Memon, Abdoulaye Doumbia, Abdul Roof Rather, Abdur Razzaque, Adama Diouf, Adriano Akira Hino, Albertino Damasceno, Alem Deksisa Abebe, Alex Antonio Florindo, Alice Mannocci, Altyn Aringazina, Andrea Backović Juričan, Andrea Poffet, Andrew Decelis, Angela Carlin, Angelica Enescu, Angélica María Ochoa Avilés, Anna Kontsevaya, Annamaria Somhegyi, Anne Vuillemin, Asmaa El Hamdouchi, Asse Amangoua Théodore, Bojan Masanovic, Brigid M. Lynch, Catalina Medina, Cecilia del Campo, Chalchisa Abdeta, Changa Moreways, Chathuranga Ranasinghe, Christina Howitt, Christine Cameron, Danijel Jurakić, David Martinez-Gomez, Dawn Tladi, Debrework Tesfaye Diro, Deepti Adlakha, Dušan Mitić, Duško Bjelica, Elżbieta Biernat, Enock M. Chisati, Estelle Victoria Lambert, Ester Cerin, Eun-Young Lee, Eva-Maria Riso, Felicia Cañete Villalba, Felix Assah, Franjo Lovrić, Gerardo A. Araya-Vargas, Giuseppe La Torre, Gloria Isabel Niño Cruz, Gul Baltaci, Haleama Al Sabbah, Hanna Nalecz, Hilde Liisa Nashandi, Hyuntae Park, Inés Revuelta-Sánchez, Jackline Jema Nusurupia, Jaime Leppe Zamora, Jaroslava Kopcakova, Javier Brazo-Sayavera, Jean-Michel Oppert, Jinlei Nie, John C. Spence, John Stewart Bradley, Jorge Mota, Josef Mitáš, Junshi Chen, Kamilah S Hylton, Karel Fromel, Karen Milton, Katja Borodulin, Keita Amadou Moustapha, Kevin Martinez-Folgar, Lara Nasreddine, Lars Breum Christiansen, Laurent Malisoux, Leapetswe Malete, Lorelie C. Grepo-Jalao, Luciana Zaranza Monteiro, Lyutha K. Al Subhi, Maja Dakskobler, Majed Alnaji, Margarita Claramunt Garro, Maria Hagströmer, Marie H. Murphy, Matthew  Mclaughlin, Mercedes Rivera-Morales, Mickey Scheinowitz, Mimoza Shkodra, Monika Piątkowska, Moushumi Chaudhury, Naif Ziyad Alrashdi, Nanette Mutrie, Niamh Murphy, Norhayati Haji Ahmad, Nour A. Obeidat, Nubia Yaneth Ruiz Gómez, Nucharapon Liangruenrom, Oscar Díaz Arnesto, Oscar Flores-Flores, Oscar Incarbone, Oyun Chimeddamba, Pascal Bovet, Pedro Magalhães, Pekka Jousilahti, Piyawat Katewongsa, Rafael Alexander Leandro Gómez, Rawan Awni Shihab, Reginald Ocansey, Réka Veress, Richard Marine, Rolando Carrizales-Ramos, Saad Younis Saeed, Said El-Ashker, Samuel Green, Sandra Kasoma, Santiago Beretervide, Se-Sergio Baldew, Selby Nichols, Selina Khoo, Seyed Ali Hosseini, Shifalika Goenka, Shima Gholamalishahi, Soewarta Kosen, Sofie Compernolle, Stefan Paul Enescu, Stevo Popovic, Susan Paudel, Susana Andrade, Sylvia Titze, Tamu Davidson, Theogene Dusingizimana, Thomas E. Dorner, Tracy L. Kolbe-Alexander, Tran Thanh Huong, Vanphanom Sychareun, Vera Jarevska-Simovska, Viliami Kulikefu Puloka, Vincent Onywera, Wanda Wendel-Vos, Yannis Dionyssiotis, and Michael Pratt

Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion.