Effects of Creatine and Carbohydrate Loading on Cycling Time Trial Performance

Med Sci Sports Exerc. 2018 Jan;50(1):141-150. doi: 10.1249/MSS.0000000000001401.


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.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Bicycling / physiology*
  • Body Weight
  • Creatine / administration & dosage*
  • Cross-Over Studies
  • Diet, Carbohydrate Loading*
  • Glycogen / analysis
  • Humans
  • Male
  • Muscle, Skeletal / physiology
  • Oxygen Consumption
  • Physical Endurance
  • Sports Nutritional Physiological Phenomena*


  • Glycogen
  • Creatine