Caffeine and Training Intensity Quantification

The Effects of Caffeine Supplementation on Training Intensity Quantification

The goal of this clinical trial is to learn about the effects of caffeine on exercise physiology and the subsequent quantification of athlete training zones in trained cyclists. The main questions that it aims to answer are:

• What are the effects of low and moderate doses of caffeine on exercise physiology.
• How do the effects of caffeine on exercise physiology affect the calculation of training zones.
• Do the effects of caffeine on exercise physiology differ between men and women.

Participants will complete four trials on a cycle ergometer as follows:

• Trial 1: participants will complete two incremental tests to determine the power outputs required to elicit 50-80% of maximal oxygen consumption for trials 2-4.
• Trials 2-4: participants will consume (in a randomized order) either a low (2 mg/kg) dose of caffeine, a moderate (5 mg/kg) dose of caffeine, or a placebo (maltodextrin), 45 minutes prior to to completing an incremental cycling test from 50-80% of maximal oxygen uptake.

Measures of heart rate, oxygen uptake, blood lactate, and perceived exertion will be recorded throughout all trials.

Researchers will compare the effects of exercise intensity, caffeine dose, and sex to see if they affect exercise physiology and training zone quantification.

Study Overview

• Status: Not yet recruiting
• Conditions: Caffeine
• Intervention / Treatment: Drug: Low caffeine dose; Drug: Moderate caffeine dose; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 36
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• To be considered for inclusion in the study, participants must be regular cyclists, between 18 and 45 years of age, capable of completing a 20 km cycling time trial at a minimum speed of 30 km/h for men and 28 km/h for women (arbitrary inclusion criteria to ensure a sufficient standard of athlete). Female participants must have a regular menstrual cycle and not be taking oral contraceptives.

Exclusion Criteria:

-

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low caffeine dose; 2 mg/kg dose of caffeine (in pill form)	Drug: Low caffeine dose; 2 mg/kg dose of caffeine in pill form
Experimental: Moderate caffeine dose; 5 mg/kg dose of caffeine (in pill form)	Drug: Moderate caffeine dose; 5 mg/kg dose of caffeine in pill form
Placebo Comparator: Placebo; 5 mg/kg dose of placebo (Maltodextrin in pill form)	Drug: Placebo; 5 mg/kg dose of maltodextrin in pill form

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Blood lactate concentration	Change from baseline in blood lactate concentration measured at rest and at seven different exercise intensities (50, 55, 60, 65, 70, 75, and 80% percent of maximal oxygen uptake) on an electromagnetically-braked cycle ergometer	From baseline to completion, up to 31 days
Heart rate	Change from baseline in heart rate measured at rest and at seven different exercise intensities (50, 55, 60, 65, 70, 75, and 80% percent of maximal oxygen uptake) on an electromagnetically-braked cycle ergometer	From baseline to completion, up to 31 days
Oxygen uptake	Change from baseline in oxygen uptake measured at rest and at seven different exercise intensities (50, 55, 60, 65, 70, 75, and 80% percent of maximal oxygen uptake) on an electromagnetically-braked cycle ergometer	From baseline to completion, up to 31 days
Perceived exertion	Change from baseline in rating of perceived exertion measured (using the 6-20 Borg scale) at seven different exercise intensities (50, 55, 60, 65, 70, 75, 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, Twickenham

Study record dates

Study Major Dates

• Study Start (Estimated): January 31, 2024
• Primary Completion (Estimated): December 31, 2025
• Study Completion (Estimated): December 31, 2025

Study Registration Dates

• First Submitted: January 8, 2024
• First Submitted That Met QC Criteria: January 8, 2024
• First Posted (Actual): January 18, 2024

Study Record Updates

• Last Update Posted (Actual): January 18, 2024
• Last Update Submitted That Met QC Criteria: January 8, 2024
• Last Verified: January 1, 2024

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: Stmarys1

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No