Acute Caffeine Intake in Older Adults (CAF+OLD)

Acute Caffeine Intake Effects in Strength and Endurance Performance in Resistance-training-naïve Older Adults

Evidence regarding the ergogenic effects of caffeine is well-established in young adults, but evidence in older adults remains scarce, particularly during dynamic resistance exercise. Therefore, this study investigated the effects of acute caffeine ingestion on upper- and lower-body muscular strength and endurance performance, as well as the influence of sex and CYP1A2 genotype, in healthy resistance training-naïve older adults.

Study Overview

• Status: Completed
• Conditions: Caffeine; Placebo - Control
• Intervention / Treatment: Dietary supplement: Caffeine; Dietary supplement: Placebo

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

Contacts and Locations

Study Locations

• Spain
  • Madrid
    • Alcalá de Henares, Madrid, Spain, 28805
      • Facultad de Medicina y Ciencias de la Salud. Universidad de Alcalá

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age between ≥ 55.
• Body mass index (BMI) lower 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.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Caffeine; Acute caffeine intake (3 mg/kg)	Dietary supplement: Caffeine; Acute caffeine intake (3 mg/kg)
Placebo Comparator: Placebo; Placebo (3 mg/kg maltodextrin)	Dietary supplement: Placebo; Placebo (3 mg/kg maltodextrin)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean velocity at different %1RM	Mean velocity at different %1RM	hrough study completion, an average of 3 weeks
Number of repetitions performed in 1 set at 65%1RM until task failure	In bench press and back squat exercises	Through study completion, an average of 3 weeks
Bar velocity deplacement performed in 1 set at 65%1RM until task failure	In bench press and back squat exercises	Through study completion, an average of 3 weeks
handgrip and isometric mid-thigh pull tests	N generated	Through study completion, an average of 3 week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
cyp1a2 polymorphism	Using saliva sample and PCR	Before the beginning of the trial
Mood state (tension, depression, anger, vigor, fatigue and confusion)	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.	Through study completion, an average of 3 weeks
Adverse effects	perception of power, endurance, energy and exertion, as well as heart, muscular and gastrointestinal discomfort	Through study completion, an average of 3 weeks

Collaborators and Investigators

• Sponsor: University of Alcala

Study record dates

Study Major Dates

• Study Start (Actual): January 10, 2024
• Primary Completion (Actual): December 21, 2025
• Study Completion (Actual): April 24, 2026

Study Registration Dates

• First Submitted: July 13, 2026
• First Submitted That Met QC Criteria: July 13, 2026
• First Posted (Actual): July 17, 2026

Study Record Updates

• Last Update Posted (Actual): July 17, 2026
• Last Update Submitted That Met QC Criteria: July 13, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Alkaloids; Purinones; Purines; Xanthines; Caffeine
• Other Study ID Numbers: CEIP/2022/3/055_1

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

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