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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Physiol. | doi: 10.3389/fphys.2019.00352

Creatine supplementation improves phosphagen energy pathway during supramaximal effort, but does not improve anaerobic capacity or performance.

  • 1Faculdade de Ciências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Brazil
  • 2Faculdade de Ciências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Brazil
  • 3Group of Applied Physiology & Nutrition, School of Physical Education and Sport, University of São Paulo, Brazil
  • 4School of Physical Education and Sport, University of São Paulo, Brazil

This study aimed to investigate the effects of short-duration creatine monohydrate supplementation on anaerobic capacity, anaerobic energy pathways, and time-to-exhaustion during high-intensity running. Fourteen healthy men underwent a graded exercise test followed by a "V" ̇"O" _"2max" confirmation test, 5 submaximal efforts, and 4 supramaximal running bouts at 115% of "V" ̇"O" _"2max" intensity (the first two supramaximal sessions were applied as familiarization trials) to measure the anaerobic capacity using two procedures; the maximum accumulated oxygen deficit (MAOD) and non-oxidative pathways energetics sum (AC[La-]+EPOCfast). The investigation was conducted in a single-blind and placebo-controlled manner, with participants performing the efforts first after being supplemented with a placebo (dextrose 20 g·day-1 for 5 days), and then, after a 7-day “placebo” washout period, they started the same procedure under creatine supplementation (20 g·day-1 for 5 days. This order was chosen due to the prolonged washout of creatine. MAOD was not different between placebo (3.35±0.65 L) and creatine conditions (3.39±0.79 L) (P=0.58) and presented a negligible effect [effect size (ES)=0.08], similar to, AC[La-]+EPOCfast (placebo condition=(3.66±0.79 Land under creatine ingestion =3.82 ± 0.85 L)(P=0.07) presenting a small effect (ES=0.20). The energetics from the phosphagen pathway increased significantly after creatine supplementation (1.66 ± 0.40 L) compared to the placebo condition (1.55±0.42 L) (P=0.03). However, the glycolytic and oxidative pathways were not different between conditions. Furthermore, time to exhaustion did not differ between placebo (160.79 ± 37.76 s) and creatine conditions (163.64 ± 38.72) (P= 0.49). Therefore, we can conclude that creatine supplementation improves the phosphagen energy contribution, but with no statistical effect on anaerobic capacity or time to exhaustion in supramaximal running.

Keywords: Creatine, Anaerobic capacity, Energy contribution, High-intensity effort, performance

Received: 01 Sep 2018; Accepted: 14 Mar 2019.

Edited by:

Martin Burtscher, University of Innsbruck, Austria

Reviewed by:

Beat Knechtle, Institute of Primary Care, University Hospital Zurich, Switzerland
Susan V. Brooks, University of Michigan, United States  

Copyright: © 2019 De Poli, Roncada, Malta, Artioli, Bertuzzi and Zagatto. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Prof. Alessandro M. Zagatto, Faculdade de Ciências, Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Bauru, 17033-360, São Paulo, Brazil, azagatto@yahoo.com.br