Caffeine Dose: Performance and Recovery

Summary

The goal of this clinical trial is to learn how different doses of caffeine taken in the evening affect rowing performance, sleep quality, and daytime alertness in trained male university rowers. The main questions it aims to answer are:

Does a low, moderate, or high caffeine dose improve rowing performance? How do these doses affect sleep and recovery after evening exercise? Participants completed four rowing tests after consuming either a placebo, low (3 mg/kg), moderate (6 mg/kg), or high (9 mg/kg) dose of caffeine. Researchers measured rowing time, power, heart rate, sleep quality, and daytime sleepiness.

The study found that moderate and high caffeine doses improved rowing performance the most. However, these same doses made it harder for participants to sleep well and feel alert the next day. Headaches and stomach issues were also more common with the high dose. The low dose gave smaller performance gains but caused fewer side effects.

This study shows that evening caffeine can boost performance but may hurt recovery and sleep. Athletes and coaches should weigh these trade-offs when using caffeine for late-day training or competition.

Conditions

• Healthy Volunteers
• Caffeine
• Sleep Quality

Interventions

DIETARY_SUPPLEMENT

Cellulose Powder

Participants consumed an inert cellulose powder dissolved in water, containing no active caffeine. The placebo was ingested orally 60 minutes prior to the rowing performance test. This condition served as the control and was administered once per session in a randomized, double-blind, crossover design.

DIETARY_SUPPLEMENT

Caffeine 3 mg/kg Oral Powder

Participants consumed caffeine in powder form at a dose of 3 milligrams per kilogram of body weight. The powder was dissolved in water and ingested orally approximately 60 minutes before the start of the 2000-meter rowing ergometer performance test. The intervention was administered once per session in a randomized, double-blind, crossover design.

DIETARY_SUPPLEMENT

Caffeine 6 mg/kg Oral Powder

Participants ingested caffeine in powder form, dissolved in water, at a dose of 6 milligrams per kilogram of body mass. The solution was consumed orally 60 minutes prior to the 2000-meter rowing performance test. This intervention was administered once per session as part of a randomized, double-blind, crossover design.

DIETARY_SUPPLEMENT

Caffeine 9 mg/kg Oral Powder

A powdered caffeine dose of 9 milligrams per kilogram was dissolved in water and consumed orally by participants 60 minutes before a 2000-meter rowing ergometer trial. The intervention was administered once per session under a randomized, double-blind, crossover design.

Sponsors & Collaborators

• Ulaç Can YILDIRIM

  lead OTHER

Principal Investigators

• Ulas C. Yildirim, pHd · Sinop University

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

QUADRUPLE

Model

CROSSOVER

Eligibility

Min Age

20 Years

Max Age

25 Years

Sex

MALE

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-07-24

Primary Completion

2022-08-24

Completion

2022-08-24

Countries

• Turkey (Türkiye)

Study Locations