Impact of Caffeine Intake on Autonomic Parameters in the Exercise of Strength

Impact of Caffeine Intake Before Exercise on the Neural Regulation of the Cardiovascular System in Physically Active Adults

The objective of this study was to evaluate the variability of the heart rate of exercise physicists with and without caffeine intake. Practitioners of resisted physical exercise, specifically bodybuilding, who are young adults between the ages of 18 and 30 will participate in the study. To define the sample size, a sample calculation was performed based considering as variable the RMSSD index (square root of the square mean of the differences between the adjacent normal iRRs). The significant difference magnitude assumed was 12 ms, considering a standard deviation of 16.2 ms, with alpha risk of 5% and beta of 80%. A minimum of 14 subjects per group were required in the survey. A total of 32 subjects will participate in the research, being these divided and allocated in different groups. Sampling will be of the intentional kind.

Study Overview

• Status: Completed
• Conditions: Autonomic Nervous System; Cardiovascular Outcomes
• Intervention / Treatment: Other: Caffeine; Dietary supplement: Placebo

Detailed Description

Caffeine supplementation has been studied in several sports modalities with the objective of investigating its repercussions on athletes' physical performance. Caffeine may lead to an obstruction of adenosine receptors (A1 and A2) and increase the activity of the Autonomic Nervous System (ANS) by releasing catecholamines in plasma, inducing tachycardia and elevating blood pressure. Such modulation of nervous system activity can be traced by assessing heart rate variability (HRV). HRV is one of the most practical methods to analyze the physiological functioning of ANS, both in pathological conditions of the individual and in the induction of other variables, being a noninvasive measure of cardiac autonomic modulation markers that analyzes the peak-R intervals a peak-R (RRI) of consecutive heartbeat. The objective of this study was to evaluate the variability of the heart rate of exercise physicists with and without caffeine intake. Practitioners of resisted physical exercise, specifically bodybuilding, who are young adults between the ages of 18 and 30 will participate in the study. To define the sample size, a sample calculation was performed based considering as variable the RMSSD index (square root of the square mean of the differences between the adjacent normal iRRs). The significant difference magnitude assumed was 12 ms, considering a standard deviation of 16.2 ms, with alpha risk of 5% and beta of 80%. A minimum of 14 subjects per group were required in the survey. A total of 32 subjects will participate in the research, being these divided and allocated in different groups. Sampling will be of the intentional kind.

The expected benefits with the result of this research are to instigate the creation of new lines of research in this context, being able to intervene in a more effective way in practitioners of physical exercise of strength, with the possibility of prevention to the autonomic alterations that are associated with the consumption of stimulant supplements, such as caffeine, and its consequences on the cardiovascular system.

• Study Type: Interventional
• Enrollment (Actual): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Ceará
    • Juazeiro do Norte, Ceará, Brazil, 63020070
      • Cicero Jonas Rodrigues Benjamim

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Male
• 18 to 30 years of age
• Body Mass Index (BMI) within the range of Eutrophy (18.5 to 24.9kg / m²)
• Experience with resistance training, uninterrupted for at least 3 months and weekly frequency of 3 sessions or more
• Do not use any medication that may interfere with cardiac autonomic modulation
• Do have no skeletal muscle damage.

Exclusion Criteria:

• Smoking patients
• As well as individuals who have already used anabolic steroids
• Cardiorespiratory diseases
• Cardiometabolic diseases
• Neurological disorders
• Other known compromises that prevent the subject from performing the procedures.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Caffeine; Volunteers will ingest 300mg caffeine one hour before strength training.	Other: Caffeine; On the first day of collection, the volunteers will not take caffeine intake, the data will be collected in a standardized way, respecting the times defined for the analysis of the cardiac activity. Then the collection will be continued. On the next day of evaluation, volunteers will receive a capsule containing 300 mg of caffeine and will be advised to consume 1 hour before the procedure.
Placebo Comparator: Placebo; Volunteers will ingest 300mg placebo one hour before strength training.	Dietary supplement: Placebo; On the first day of collection, the volunteers will not take placebo intake, the data will be collected in a standardized way, respecting the times defined for the analysis of the cardiac activity. Then the collection will be continued. On the next day of evaluation, volunteers will receive a capsule containing 300 mg of placebo and will be advised to consume 1 hour before the procedure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Caffeine effects on heart rate variability (based on frequency, time domain and Chaos)		up to 1 year
Blood pressure (mmHg)	Caffeine effects blood pressure recovery following strength exercise	up to 1 year
Heart rate (beats per minute)	Caffeine effects heart rate recovery following strength exercise	up to 1 year

Collaborators and Investigators

• Sponsor: University of Pernambuco

Study record dates

Study Major Dates

• Study Start (Actual): December 19, 2018
• Primary Completion (Actual): March 19, 2019
• Study Completion (Actual): March 20, 2019

Study Registration Dates

• First Submitted: March 26, 2019
• First Submitted That Met QC Criteria: March 29, 2019
• First Posted (Actual): April 2, 2019

Study Record Updates

• Last Update Posted (Actual): April 18, 2019
• Last Update Submitted That Met QC Criteria: April 16, 2019
• Last Verified: April 1, 2019

More Information

Terms related to this study

• Keywords: Exercise; Autonomic Nervous System; Heart Rate Variability; Caffeine; Cardiovascular Risk Factor
• 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: UPernambuco

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: No, we intend to disseminate the results in scientific journals.

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