The Repeatability of the Effect of Caffeine Supplementation on Submaximal Physiological Responses and Cycling Time Trial Performance
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Caffeine, Placebo, Caffeine.
- Who it may be relevant to
- Registry conditions: Caffeine. Basic parameters: 18 years — 35 years · Male.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
Recently, Grgic (2018) discussed the concept of responders and non-responders to caffeine supplementation highlighting the importance of the repeatability of results. However, the number of studies that have investigated this idea by repeating the same time-trial performance test multiple times with the same caffeine dose is sparse (Astorino et al., 2012; Del Coso et al., 2019). Furthermore, studies have shown that differences in the CYP1A2 genotype may account for some of the variation in time-trial performance (Guest et al., 2018). Thus, the current study aims to identify whether the effects of moderate caffeine supplementation (5 mg/kg) on time-trial performance are repeatable to aid the identification of responders and non-responders. Additionally, the study aims to determine if the CYP1A2 genotype may explain any of the variability in time-trial performance in trained male cyclists.
Interventions
- Dietary supplement Caffeine
5 mg/kg of caffeine in pill form - Dietary supplement Placebo
5 mg/kg dose of maltodextrin in pill form - Dietary supplement Caffeine
5 mg/kg dose of caffeine in pill form
Primary outcome measures
- Blood lactate concentration [Time frame: From baseline to completion, up to 31 days]
- Heart rate [Time frame: From baseline to completion, up to 31 days]
- Oxygen uptake [Time frame: From baseline to completion, up to 31 days]
- Perceived exertion [Time frame: From baseline to completion, up to 31 days]
- Time trial completion time [Time frame: From baseline to completion, up to 31 days]
Eligibility criteria
Inclusion criteria
- To be considered for inclusion in the study, participants must be regular cyclists, between 18 and 35 years of age, capable of completing a 20 km cycling time trial at a minimum speed of 30 km/h (arbitrary inclusion criteria to ensure a sufficient standard of athlete).
Exclusion criteria
\-
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Crossover
- Masking
- Double blind
- Primary purpose
- Basic science
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT06935214 · SMU_ETHICS_2024-25_992