The Effects of Caffeine on Exercise Physiology and Time-trial Performance in a Hot Environment

NCT07129200 · Status: NOT_YET_RECRUITING · Phase: NA · Type: INTERVENTIONAL · Enrollment: 15

Last updated 2025-08-19

No results posted yet for this study

Summary

Maintaining a stable core temperature is vital for physiological function; yet, exercise in heat can be problematic, and there is risk of exertional heat-related illness (Flouris \& Schlader, 2015; Leyk et al., 2019; Périard et al., 2021; Tyler et al., 2016; Veltmeijer et al., 2015). While aerobic fitness improves heat tolerance (Alhadad et al., 2019), strategies like acclimation and pre-cooling also mitigate heat stress (Casadio et al., 2016; Lorenzo et al., 2010; Ross et al., 2013; Siegel et al., 2010). Caffeine, an ergogenic aid (Del Corso et al., 2011; John et al., 2024), is known to enhance performance via adenosine antagonism and increased catecholamines in normothermic environments (Fredholm et al., 1999; Graham \& Spriet, 1991). However, effects in heat are inconsistent (Ganio et al., 2009; Zhang et al., 2014), possibly due to caffeine reducing the ability to thermoregulate effectively. Therefore, the aim of this study is to investigate the effects of a moderate dose of caffeine (5 mg/kg) on thermoregulation during a 30-minute running time trial in 35°C heat.

Conditions

  • Caffeine
  • Thermoregulation

Interventions

OTHER

Hot environment

Hot environment of 35 degrees Celsius

OTHER

Thermoneutral environment

Thermoneutral environment of 18 degrees Celsius

Sponsors & Collaborators

  • St. Mary's University, Twickenham

    lead OTHER

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Model
CROSSOVER

Eligibility

Min Age
18 Years
Max Age
45 Years
Sex
MALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2025-08-22
Primary Completion
2026-04-30
Completion
2026-06-30

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Read the full study record

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View NCT07129200 on ClinicalTrials.gov