NCT05521386

Brief Summary

In previous research we have shown that an acute caffeine dose of 5 mg/kg body mass reduces heart rate at rest and during low intensity exercise, with the effect dissipating as exercise intensity increases. If, as suspected, the effect at rest and at low intensities is due to an effect of caffeine on parasympathetic activity, this is likely to be reflected in an increase in heart rate variability (the beat-to-beat fluctuation in heart rate). The aim of this study is therefore to investigate the effect of caffeine on heart rate and heart rate variability at rest and during submaximal exercise.

Trial Health

35
At Risk

Trial Health Score

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

Trial has exceeded expected completion date
Enrollment
16

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Sep 2022

Shorter than P25 for not_applicable

Status
unknown

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

Trial Relationships

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Study Timeline

Key milestones and dates

First Submitted

Initial submission to the registry

August 26, 2022

Completed
4 days until next milestone

First Posted

Study publicly available on registry

August 30, 2022

Completed
2 days until next milestone

Study Start

First participant enrolled

September 1, 2022

Completed
7 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 31, 2023

Completed
1 month until next milestone

Study Completion

Last participant's last visit for all outcomes

April 30, 2023

Completed
Last Updated

August 30, 2022

Status Verified

August 1, 2022

Enrollment Period

7 months

First QC Date

August 26, 2022

Last Update Submit

August 26, 2022

Conditions

Caffeine

Outcome Measures

Primary Outcomes (1)

  • Heart rate variability

    Change from baseline in heart rate variability measured at rest and at five different exercise intensities (40, 50, 60, 70 and 80% percent of maximal oxygen uptake) on an electromagnetically-braked cycle ergometer

    From baseline to completion, up to 31 days

Secondary Outcomes (1)

  • Heart rate

    From baseline to completion, up to 31 days

Study Arms (2)

Caffeine

EXPERIMENTAL

caffeine dose of 5 mg per kg of body mass administered orally via a gelatine capsule

Drug: Caffeine

Placebo

PLACEBO COMPARATOR

maltodextrin (placebo) dose of 5 mg per kg of body mass administered orally via a gelatine capsule

Drug: Placebo

Interventions

CaffeineDRUG

Single pill in an acute dose of 5 mg per kg of body mass

Caffeine
PlaceboDRUG

Single pill in an acute dose of 5 mg per kg of body mass

Placebo

Eligibility Criteria

Age18 Years - 55 Years
Sexmale
Healthy VolunteersYes
Age GroupsAdult (18-64)

You may qualify if:

  • Trained cyclists

You may not qualify if:

  • Injured or a contraindicative medical condition

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Related Publications (1)

  • Glaister M, Lythgoe D, Kamath S. The Effects of Caffeine on Heart Rate and Heart Rate Variability at Rest and During Submaximal Cycling Exercise. Res Q Exerc Sport. 2025 Mar;96(1):155-163. doi: 10.1080/02701367.2024.2377303. Epub 2024 Jul 15.

    PMID: 39008947DERIVED

MeSH Terms

Interventions

Caffeine

Intervention Hierarchy (Ancestors)

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

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

August 26, 2022

First Posted

August 30, 2022

Study Start

September 1, 2022

Primary Completion

March 31, 2023

Study Completion

April 30, 2023

Last Updated

August 30, 2022

Record last verified: 2022-08