Effects of Creatine and Carbohydrate Loading on Cycling Time Trial Performance
Tomcik KA, Camera DM, Bone JL, Ross ML, Jeacocke NA, Tachtsis B, Senden J, VAN Loon LJC, Hawley JA, Burke LM
Medicine and science in sports and exercise · 23 citations
Review labels
Neutral facts our review recorded about how this study was done. They describe method, never whether we like the result.
How it was studied
- Design
- Randomized controlled trial (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Funding not disclosed
Publication
- Published
- 2017-08-11 · Med Sci Sports Exerc · vol. 50 · issue 1 · pp. 141–150
- Publisher
- Lippincott Williams & Wilkins
- Cited
- 31 citations · more than 66% of similar papers · 0.7× the field average
- References
- 41 works
- Access
- Paywalled
- Research areas
- Muscle metabolism and nutrition · Exercise and Physiological Responses · Cardiovascular and exercise physiology
- Keywords
- Sprint, Cycling, Time trial, Creatine, Animal science, Placebo, Medicine, Crossover study, Carbohydrate, Internal medicine, Physical therapy, Biology, Heart rate, Blood pressure
- MeSH
- muscle, skeletal, humans, body weight, creatine, glycogen, cross-over studies, oxygen consumption, physical endurance, bicycling, adult, male, sports nutritional physiological phenomena, diet, carbohydrate loading
10 authors
From AU, NL, GB
- KRISTYEN A. TOMCIKAustralian Catholic University
- DONNY MICHAEL CAMERAAustralian Catholic University
- Julia L. BoneAustralian Sports Commission; Australian Sports Commission; ACT Government; Australian Catholic University
- MEGAN L. R. ROSSAustralian Sports Commission; Australian Sports Commission; ACT Government; Australian Catholic University
- NIKKI A. JEACOCKEAustralian Sports Commission; Australian Sports Commission; ACT Government
- Bill TachtsisAustralian Catholic University
Abstract
Introduction
Creatine (Cr) and carbohydrate loadings are dietary strategies used to enhance exercise capacity. This study examined the metabolic and performance effects of a combined CR and CHO loading regiment on time trial (TT) cycling bouts.
Methods
Eighteen well-trained (~65 mL·kg·min V˙O2peak) men completed three performance trials (PT) that comprised a 120-km cycling TT interspersed with alternating 1- and 4-km sprints (six sprints each) performed every 10 km followed by an inclined ride to fatigue (~90% V˙O2peak). Subjects were pair matched into either CR-loaded (20 g·d for 5 d + 3 g·d for 9 d) or placebo (PLA) groups (n = 9) after the completion of PT1. All subjects undertook a crossover application of the carbohydrate interventions, consuming either moderate (6 g·kg body mass (BM) per day; MOD) or CHO-loaded (12 g·kg BM·d; LOAD) diets before PT2 and PT3. Muscle biopsies were taken before PT1, 18 h after PT1, and before both PT2 and PT3.
Results
No significant differences in overall TT or inclined ride times were observed between intervention groups. PLA + LOAD improved power above baseline (P < 0.05) during the final 1-km sprint, whereas CR + MOD and CR + LOAD improved power (P < 0.05) during the final 4-km sprint. Greater power was achieved with MOD and LOAD compared with baseline with PLA (P < 0.05). CR increased pre-PT BM compared with PLA (+1.54% vs +0.99% from baseline). CR + LOAD facilitated greater [total CR] (P < 0.05 vs baseline) and muscle [glycogen] (P < 0.01 vs baseline and MOD) compared with PLA + LOAD. Mechanistic target of rapamycin decreased from baseline after glycogen depletion (~30%; P < 0.05).
Conclusions
Power output in the closing sprints of exhaustive TT cycling increased with CR ingestion despite a CR-mediated increase in weight. CR cosupplemented with carbohydrates may therefore be beneficial strategy for late-stage breakaway moments in endurance events.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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