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Completed

NCT Number: NCT06606652

Caffeine, Resistance Exercise and EMG

Introduction: Several studies have evaluated and confirmed the ergogenic effects of acute caffeine intake on sports performance. However, some studies suggest that this effect predominantly occurs in large muscle groups, potentially due to increased skeletal muscle electrical activity.

Objectives: This study aims to evaluate the acute effects of caffeine intake on strength, power, muscle endurance, and muscle electrical activity in young adults. It will also analyze the influence of circadian rhythms (morning vs. afternoon) on exercise performance (bench press vs. squat).

Methods: Twelve healthy, physically active participants will be recruited for the study. Using a triple-blind, crossover, randomized, and controlled design, participants will ingest either caffeine (3 mg/kg body mass) or a placebo (maltodextrin, 3 mg/kg) 60 minutes before the trial. Muscular strength, power, and endurance performance will then be assessed through 1RM tests, and at 25%, 50%, 75%, and 90% of 1RM, along with muscle endurance tests at 65% of 1RM, for both squat and bench press exercises. EMG will be used to measure skeletal muscle electrical activity during the tests. The experimental sessions will be conducted in the morning (8:00 am to 10:00 am) and the afternoon (4:30 pm to 6:30 pm).

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Key information

Conditions

Caffeine

Age range

18 year–35 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Facultad de Medicina y Ciencias de la Salud. Universidad de Alcalá

Alcalá de Henares, Madrid, 28805, Spain

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age between 18 and 35 years.
  • Body Mass Index (BMI) < 25 kg/m².
  • Resistance-trained individuals (more than 2 years of structured training).
  • Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from exercising.
  • Participants must be able to perform the tests described in the following section.

Exclusion criteria

  • History of neuromuscular diseases, heart disease, or conditions that may affect liver or muscle metabolism.
  • Use of drugs, stimulants, or sports supplements that could interfere with the dietary supplement used in the study.
  • Sedentary habits (less than 150 minutes/week of moderate exercise).
  • Having undergone prolonged periods of physical inactivity in the 6 months prior to the study.
  • Engaging in strenuous exercise within 48 hours prior to the tests.
  • Failure to replicate the same food intake on both experimental days.
  • Consumption of caffeine or any other stimulant after 6 pm on the day before the tests, to avoid headaches, discomfort, or lethargy in regular caffeine consumers.

Treatment and study plan

Caffeine

Dietary Supplement

Acute caffeine intake (3 mg/kg)

Placebo

Dietary Supplement

Acute placebo intake (3 mg/kg of maltodextrin)

Primary outcomes

  1. Mean velocity at different %1RM

    Time frame: Through study completion, an average of 4 weeks

    Measuring bar mean velocity desplacement during bench press and back squat exercises.

  2. Peak velocity at different %1RM

    Time frame: Through study completion, an average of 4 weeks

    Measuring bar peak velocity and time to reach peak velocity of bar desplacement during bench press and back squat exercises.

  3. Mean power output at different %1RM

    Time frame: Through study completion, an average of 4 weeks

    Measuring during bench press and back squat exercises.

  4. Peak power output and time to reach peak power output at different %1RM

    Time frame: Through study completion, an average of 4 weeks

    Measuring during bench press and back squat exercises.

  5. Number of repetitions performed in 1 set at 65%1RM until task failure

    Time frame: Through study completion, an average of 4 weeks

  6. Bar velocity deplacement performed in 1 set at 65%1RM until task failure

    Time frame: Through study completion, an average of 4 weeks

    In bench press and back squat exercises

  7. Power output generated in 1 set at 65%1RM until task failure

    Time frame: Through study completion, an average of 4 weeks

    In bench press and back squat exercise

  8. Muscle electrical activity (EMG).

    Time frame: Through study completion, an average of 4 weeks

    Root-mean-square (RMS) and maximal voluntary contraction (MVC) from pectoralis major and triceps (bench press) and from rectus femoris and vastus lateralis (Back squat).

Secondary outcomes

  1. Mood state (tension, depression, anger, vigor, fatigue and confusion)

    Time frame: Through study completion, an average of 4 weeks

    Participants graded a set of 29 items related to the mood on a Likert scale from 0 (not at all) to 4 (extremely) in reply to the question: How do you feel at this moment? To assess six scales: tension, depression, anger, vigor, fatigue and confusion.

  2. Adverse effects

    Time frame: Through study completion, an average of 4 weeks

    perception of power, endurance, energy and exertion, as well as heart, muscular and gastrointestinal discomfort.

Sponsors and collaborators

Lead sponsor

University of Alcala

Other

Registry information

Official study title

Effect of Acute Caffeine Intake on Muscle Electrical Activity and Muscular Strength, Power, and Endurance Performance

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Sep 23, 2024
Registry last updated
Sep 23, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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