NCT02109783

Brief Summary

Numerous studies have investigated the effect of caffeine on athletic performance, but the findings have not been consistent. This is due, in part, to the differences in response that has been observed both within and between studies. Previous research in our lab has shown that genetic variations affecting caffeine metabolism modify the association between caffeine and heart disease. We hypothesize that the inconsistencies among studies relating caffeine and athletic performance may be due to genetic differences in caffeine metabolism or response. Male athletes will take part in an intervention of caffeine versus placebo, using a randomized double-blinded placebo-controlled design, which will test various exercise protocols (power, strength, anaerobic capacity, endurance) that are associated with performance across multiple sports. We will conduct a genome-wide association study, which is an approach that involves scanning for markers across the genomes of our study participants together, not individuals, to find genetic variations associated with a particular trait such as VO2 max, lactate clearance efficiency, muscle fiber type and changes in exercise performance following caffeine. We will also examine known genetic variations that are associated with caffeine metabolism and response, to determine if these genes also affect response to exercise after ingesting caffeine. Subjects will be paid $50.

Trial Health

43
At Risk

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
100

participants targeted

Target at P75+ for not_applicable healthy

Timeline
Completed

Started Jun 2014

Typical duration for not_applicable healthy

Geographic Reach
1 country

1 active site

Status
unknown

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

April 3, 2014

Completed
7 days until next milestone

First Posted

Study publicly available on registry

April 10, 2014

Completed
2 months until next milestone

Study Start

First participant enrolled

June 1, 2014

Completed
1.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

January 1, 2016

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

January 1, 2016

Completed
Last Updated

December 2, 2015

Status Verified

November 1, 2015

Enrollment Period

1.6 years

First QC Date

April 3, 2014

Last Update Submit

November 30, 2015

Conditions

Healthy

Keywords

AthletesErgogenic aidsCaffeineNutrigenomicsGenotype

Outcome Measures

Primary Outcomes (1)

  • Efficacy of caffeine to improve power, strength and speed

    To determine if their is a positive effect (improvement) effect of 2 or 4 mg of caffeine per kilogram of body mass on four distinct components of fitness: power, strength, anaerobic and aerobic capacity. Therefore, to determine the efficacy of caffeine to shorten time to completion in time trial, and increase power/strength in wingate, vertical jump and handgrip tests.

    2 hours

Secondary Outcomes (1)

  • Individual genotypes, caffeine ingestion and athletic performance

    1 day

Study Arms (3)

Caffeine 4 mg

ACTIVE COMPARATOR

To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform 4 exercise tests.

Dietary Supplement: Caffeine 4 mg

Caffeine 2 mg

ACTIVE COMPARATOR

To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform 4 exercise tests.

Dietary Supplement: Caffeine 2mg

Caffeine 0 mg

PLACEBO COMPARATOR

To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform 4 exercise tests.

Dietary Supplement: Caffeine 0

Interventions

Caffeine 2mgDIETARY_SUPPLEMENT

Caffeine 2 mg versus 4 mg/kg or placebo

Caffeine 2 mg
Caffeine 4 mgDIETARY_SUPPLEMENT

To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform 4 exercise tests.

Caffeine 4 mg
Caffeine 0DIETARY_SUPPLEMENT

To compare exercise performance of 2 or 4 mg of caffeine per kilogram of body weight to placebo within subjects. Subjects will perform 4 exercise tests.

Caffeine 0 mg

Eligibility Criteria

Age18 Years - 35 Years
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • healthy 18-35 yrs
  • athlete competing/training in given sport 3 or more years
  • currently competing at Varsity, Professional, National level or recreationally but also competing

You may not qualify if:

  • medical conditions affected by caffeine / avoidance of caffeine
  • injured / not training
  • unable to abstain from caffeine for 4 weeks during study

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University ofToronto

Toronto, Ontario, M5S 3E2, Canada

Location

Related Publications (4)

  • Tucker MA, Hargreaves JM, Clarke JC, Dale DL, Blackwell GJ. The effect of caffeine on maximal oxygen uptake and vertical jump performance in male basketball players. J Strength Cond Res. 2013 Feb;27(2):382-7. doi: 10.1519/JSC.0b013e31825922aa.

    PMID: 22561972BACKGROUND

  • Sicova M, Guest NS, Tyrrell PN, El-Sohemy A. Caffeine, genetic variation and anaerobic performance in male athletes: a randomized controlled trial. Eur J Appl Physiol. 2021 Dec;121(12):3499-3513. doi: 10.1007/s00421-021-04799-x. Epub 2021 Sep 16.

    PMID: 34529114DERIVED

  • Thakkar D, Sicova M, Guest NS, Garcia-Bailo B, El-Sohemy A. HFE Genotype and Endurance Performance in Competitive Male Athletes. Med Sci Sports Exerc. 2021 Jul 1;53(7):1385-1390. doi: 10.1249/MSS.0000000000002595.

    PMID: 33433155DERIVED

  • Guest NS, Corey P, Tyrrell PN, El-Sohemy A. Effect of Caffeine on Endurance Performance in Athletes May Depend on HTR2A and CYP1A2 Genotypes. J Strength Cond Res. 2022 Sep 1;36(9):2486-2492. doi: 10.1519/JSC.0000000000003665. Epub 2020 Jun 17.

    PMID: 32569126DERIVED

MeSH Terms

Interventions

Caffeine

Intervention Hierarchy (Ancestors)

XanthinesAlkaloidsHeterocyclic CompoundsPurinonesPurinesHeterocyclic Compounds, 2-RingHeterocyclic Compounds, Fused-Ring

Study Officials

  • Ahmed El-Sohemy, PhD

    University of Toronto

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Associate Professor

Study Record Dates

First Submitted

April 3, 2014

First Posted

April 10, 2014

Study Start

June 1, 2014

Primary Completion

January 1, 2016

Study Completion

January 1, 2016

Last Updated

December 2, 2015

Record last verified: 2015-11

Locations

CA(1)