The Effects of Caffeine on Heart Rate and Heart Rate Variability

The Effects of Caffeine Supplementation on Heart Rate and Heart Rate Variability at Rest and During Submaximal Exercise

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Caffeine
• Intervention / Treatment: Drug: Caffeine; Drug: Placebo

• Study Type: Interventional
• Enrollment (Anticipated): 16
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 55 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Trained cyclists

Exclusion Criteria:

• Injured or a contraindicative medical condition

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Caffeine; caffeine dose of 5 mg per kg of body mass administered orally via a gelatine capsule	Drug: Caffeine; Single pill in an acute dose of 5 mg per kg of body mass
PLACEBO_COMPARATOR: Placebo; maltodextrin (placebo) dose of 5 mg per kg of body mass administered orally via a gelatine capsule	Drug: Placebo; Single pill in an acute dose of 5 mg per kg of body mass

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
Heart rate	Change from baseline in heart rate 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

Collaborators and Investigators

• Sponsor: St Mary's University College

Study record dates

Study Major Dates

• Study Start (ANTICIPATED): September 1, 2022
• Primary Completion (ANTICIPATED): March 31, 2023
• Study Completion (ANTICIPATED): April 30, 2023

Study Registration Dates

• First Submitted: August 26, 2022
• First Submitted That Met QC Criteria: August 26, 2022
• First Posted (ACTUAL): August 30, 2022

Study Record Updates

• Last Update Posted (ACTUAL): August 30, 2022
• Last Update Submitted That Met QC Criteria: August 26, 2022
• Last Verified: August 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Enzyme Inhibitors; Purinergic Antagonists; Purinergic Agents; Phosphodiesterase Inhibitors; Purinergic P1 Receptor Antagonists; Central Nervous System Stimulants; Caffeine
• Other Study ID Numbers: StMarysUC5

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No