Skip to content

Caffeine, CYPA12 and Resistance Training

Influence of CYP1A2 on the Prolonged Effect of Caffeine Intake on Resistance Training

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT06610123
Enrollment
48
Registered
2024-09-24
Start date
2024-04-01
Completion date
2026-04-30
Last updated
2026-05-06

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Caffeine and Resistance Training, CYP1A2 Polymorphism

Brief summary

Introduction: Several studies have evaluated and confirmed the ergogenic effect of acute caffeine intake on sports performance, specifically on strength and power performance. However, it remains to be elucidated how CYP1A2 polymorphism influences the prolonged effects of caffeine on this type of exercise. Objectives: The present study aims to analyze the prolonged effects of caffeine intake on neuromuscular adaptations to resistance training according to CYP1A2 polymorphism in men and women.

Interventions

DIETARY_SUPPLEMENTCaffeine and Resistance training

Acute caffeine intake (3 mg/kg) prior each resistance training session of a 8 weeks training program.

DIETARY_SUPPLEMENTPlacebo and Resistance training

Acute placebo intake (3 mg/kg of maltodextrin) prior each resistance training session of a 8 weeks training program.

Sponsors

University of Alcala
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)

Masking description

Statistician

Eligibility

Sex/Gender
ALL
Age
18 Years to 35 Years
Healthy volunteers
Yes

Inclusion criteria

* Age between ≥ 18 and ≤ 35 years. * Body mass index (BMI) lowe than 25 kg/m². * Physically active subjects (≥ 150 min/week of moderate exercise). * Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from performing physical exercise. * Participants capable of performing the tests.

Exclusion criteria

* History of neuromuscular, cardiac, or diseases that could affect liver or muscle metabolism. * Use of drugs or other stimulants that interfere with caffeine intake and intestinal absorption during the tests and study. * Body mass index (BMI) ≥ 25 kg/m². * Having undergone prolonged periods of forced physical inactivity during the 6 months prior to the study. * Performing strenuous exercise within 48 hours prior to the tests. * Failing to replicate the same food intake on the two experimental days. * Consuming caffeine after 6 PM on the day prior to training or testing.

Design outcomes

Primary

MeasureTime frameDescription
Mean velocity at different %1RMThrough study completion, an average of 12 weeksMeasuring bar mean velocity desplacement during bench press and back squat exercises.
Peak velocity at different %1RMThrough study completion, an average of 12 weeksMeasuring 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 12 weeksMeasuring 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 12 weeksMeasuring during bench press and back squat exercises.
Number of repetitions performed at 65%1RM until task failureThrough study completion, an average of 12 weeksIn bench press and back squat exercises
Bar velocity deplacement performed in 1 set at 65%1RM until task failureThrough study completion, an average of 12 weeksIn bench press and back squat exercises
Power output generated in 1 set at 65%1RM until task failureThrough study completion, an average of 12 weeksIn bench press and back squat exercise
Resting Metabolic Rate (RMR)Through study completion, an average of 12 weeksKcal at rest using a metabolic chart.
Maximal Fat Oxidation Rate (MFO)Through study completion, an average of 12 weeksg/min (MFO) using a metabolic chart.

Secondary

MeasureTime frameDescription
Fat-free massThrough study completion, an average of 4 weeksUsing electrical bioimpedance and untrasound in the quadriceps muscle
Fat massThrough study completion, an average of 12 weeksUsing electrical bioimpedance (kg and % of body mass)
Physical activity (METs-min/wk)Through study completion, an average of 12 weeksUsing IPAQ
Dietary (g/kg of macronutrients)Through study completion, an average of 12 weeksUsing a 24-total recall
Mood stateThrough study completion, an average of 12 weeksParticipants 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 12 weeksAdverse effects. perception of power, endurance, energy and exertion, as well as heart, muscular and gastrointestinal discomfort.

Countries

Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 7, 2026