MedPath

Reproducibility of Acute Caffeine Effect

Not Applicable
Recruiting
Conditions
Caffeine and Resistance Exercise
Interventions
Dietary Supplement: Caffeine
Dietary Supplement: Placebo
Registration Number
NCT06606639
Lead Sponsor
University of Alcala
Brief Summary

Introduction: Various studies have evaluated and verified the ergogenic effect of acute caffeine intake on sports performance, specifically on strength and power performance. However, all experimental investigations designed so far have been based on the comparison of the \"caffeine\" and \"placebo\" conditions in a single trial, not considering the reproducibility and variability of caffeine in multiple trials.

Objectives: The present study aims to evaluate the reproducibility and replicability of the acute effect of caffeine intake on energy metabolism and the muscular production of force, power and endurance, according to sex (men vs women) and type of exercise ( bench press vs squat).

Detailed Description

Not available

Recruitment & Eligibility

Status
RECRUITING
Sex
All
Target Recruitment
48
Inclusion Criteria
  • Age between ≥ 18 and ≤ 35 years.
  • Body Mass Index (BMI) < 25 kg/m².
  • Resistance-trained individuals (> 2 years of structured trained).
  • 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 diseases, or diseases that may affect liver or muscle metabolism.
  • Use of drugs, other stimulants or sport supplements that interfere with the the study dietary supplement.
  • Sedentary habits (<150 min/week of moderate exercise).
  • Having undergone prolonged periods of forced physical inactivity during the 6 months prior to the study.
  • Performing strenuous exercise during the 48 hours prior to the tests.
  • Failure to replicate the same food intake on the two days of the experiments.
  • Consuming caffeine or any other stimulant after 6 pm the day before the training or tests, to avoid headaches, discomfort, or lethargy among regular caffeine consumers.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
Caffeine - Trial 1Caffeine-
Caffeine - Trial 2Caffeine-
Caffeine - Trial 3Caffeine-
Placebo - Trial 1Placebo-
Placebo - Trial 2Placebo-
Primary Outcome Measures
NameTimeMethod
Mean velocity at different %1RMThrough study completion, an average of 4 weeks

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

Peak velocity at different %1RMThrough 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.

Mean power output at different %1RMThrough study completion, an average of 4 weeks

Measuring during bench press and back squat exercises.

Peak power output and time to reach peak power output at different %1RMThrough study completion, an average of 4 weeks

Measuring during bench press and back squat exercises.

Number of repetitions performed in 1 set at 65%1RM until task failureThrough study completion, an average of 4 weeks

In bench press and back squat exercises

Bar velocity deplacement performed in 1 set at 65%1RM until task failureThrough study completion, an average of 4 weeks

In bench press and back squat exercises

Power output generated in 1 set at 65%1RM until task failureThrough study completion, an average of 4 weeks

In bench press and back squat exercise

Resting Metabolic Rate (RMR)Through study completion, an average of 4 weeks

Kcal at rest measuring (RMR) using a metabolic chart.

Maximal Fat Oxidation Rate (MFO)Through study completion, an average of 4 weeks

g/min (MFO) using a metabolic chart.

Secondary Outcome Measures
NameTimeMethod
Physical activity (METs-min/wk)Through study completion, an average of 4 weeks

Using IPAQ

Dietary (g/kg of macronutrients)Through study completion, an average of 4 weeks

Using 24-total recall

Mood stateThrough study completion, an average of 4 weeks

Mood. 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.

Adverse effectsThrough study completion, an average of 4 weeks

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

Fat massThrough study completion, an average of 4 weeks

Using electrical bioimpedance (kg and % of body mass)

Fat-free massThrough study completion, an average of 4 weeks

Using electrical bioimpedance (kg and % of body mass)

Trial Locations

Locations (1)

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

🇪🇸

Alcalá de Henares, Madrid, Spain

© Copyright 2025. All Rights Reserved by MedPath