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Coinciding exercise with peak serum caffeine does not improve cycling performance

Journal Article


Abstract


  • Objectives

    To investigate whether coinciding peak serum caffeine concentration with the onset of exercise enhances subsequent endurance performance.

    Design

    Randomised, double-blind, crossover.

    Methods

    In this randomised, placebo-controlled, double-blind crossover study, 14 male trained cyclists and triathletes (age 31 ± 5 year, body mass 75.4 ± 5.7 kg, VO2max 69.5 ± 6.1 mL kg−1 min−1 and peak power output 417 ± 35 W, mean ± SD) consumed 6 mg kg−1 caffeine or a placebo either 1 h (C1 h) prior to completing a 40 km time trial or when the start of exercise coincided with individual peak serum caffeine concentrations (Cpeak). Cpeak was determined from a separate ‘caffeine profiling’ session that involved monitoring caffeine concentrations in the blood every 30 min over a 4 h period.

    Results

    Following caffeine ingestion, peak serum caffeine occurred 120 min in 12 participants and 150 min in 2 participants. Time to complete the 40 km time trial was significantly faster (2.0%; p = 0.002) in C1 h compared to placebo. No statistically significant improvement in performance was noted in the Cpeak trial versus placebo (1.1%; p = 0.240). Whilst no differences in metabolic markers were found between Cpeak and placebo conditions, plasma concentrations of glucose (p = 0.005), norepinephrine and epinephrine (p ≤ 0.002) were higher in the C1 h trial 6 min post-exercise versus placebo.

    Conclusions

    In contrast to coinciding peak serum caffeine concentration with exercise onset, caffeine consumed 60 min prior to exercise resulted in significant improvements in 40 km time trial performance. The ergogenic effect of caffeine was not found to be related to peak caffeine concentration in the blood at the onset of endurance exercise.

UOW Authors


  •   Jenkins, David G. (external author)
  •   Skinner, Tina L. (external author)
  •   Leveritt, Michael D. (external author)
  •   Coombes, Jeff S. (external author)
  •   Taaffe, Dennis R. (external author)

Publication Date


  • 2013

Citation


  • Skinner, T. L., Jenkins, D. G., Taaffe, D. R., Leveritt, M. D. & Coombes, J. S. (2013). Coinciding exercise with peak serum caffeine does not improve cycling performance. Journal of Science and Medicine in Sport, 16 (1), 54-59.

Scopus Eid


  • 2-s2.0-84871718020

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/2545

Has Global Citation Frequency


Number Of Pages


  • 5

Start Page


  • 54

End Page


  • 59

Volume


  • 16

Issue


  • 1

Abstract


  • Objectives

    To investigate whether coinciding peak serum caffeine concentration with the onset of exercise enhances subsequent endurance performance.

    Design

    Randomised, double-blind, crossover.

    Methods

    In this randomised, placebo-controlled, double-blind crossover study, 14 male trained cyclists and triathletes (age 31 ± 5 year, body mass 75.4 ± 5.7 kg, VO2max 69.5 ± 6.1 mL kg−1 min−1 and peak power output 417 ± 35 W, mean ± SD) consumed 6 mg kg−1 caffeine or a placebo either 1 h (C1 h) prior to completing a 40 km time trial or when the start of exercise coincided with individual peak serum caffeine concentrations (Cpeak). Cpeak was determined from a separate ‘caffeine profiling’ session that involved monitoring caffeine concentrations in the blood every 30 min over a 4 h period.

    Results

    Following caffeine ingestion, peak serum caffeine occurred 120 min in 12 participants and 150 min in 2 participants. Time to complete the 40 km time trial was significantly faster (2.0%; p = 0.002) in C1 h compared to placebo. No statistically significant improvement in performance was noted in the Cpeak trial versus placebo (1.1%; p = 0.240). Whilst no differences in metabolic markers were found between Cpeak and placebo conditions, plasma concentrations of glucose (p = 0.005), norepinephrine and epinephrine (p ≤ 0.002) were higher in the C1 h trial 6 min post-exercise versus placebo.

    Conclusions

    In contrast to coinciding peak serum caffeine concentration with exercise onset, caffeine consumed 60 min prior to exercise resulted in significant improvements in 40 km time trial performance. The ergogenic effect of caffeine was not found to be related to peak caffeine concentration in the blood at the onset of endurance exercise.

UOW Authors


  •   Jenkins, David G. (external author)
  •   Skinner, Tina L. (external author)
  •   Leveritt, Michael D. (external author)
  •   Coombes, Jeff S. (external author)
  •   Taaffe, Dennis R. (external author)

Publication Date


  • 2013

Citation


  • Skinner, T. L., Jenkins, D. G., Taaffe, D. R., Leveritt, M. D. & Coombes, J. S. (2013). Coinciding exercise with peak serum caffeine does not improve cycling performance. Journal of Science and Medicine in Sport, 16 (1), 54-59.

Scopus Eid


  • 2-s2.0-84871718020

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/2545

Has Global Citation Frequency


Number Of Pages


  • 5

Start Page


  • 54

End Page


  • 59

Volume


  • 16

Issue


  • 1