Biology of Sport
eISSN: 2083-1862
ISSN: 0860-021X
Biology of Sport
Current Issue Manuscripts accepted About the journal Editorial board Abstracting and indexing Archive Ethical standards and procedures Contact Instructions for authors Journal's Reviewers Special Information
Editorial System
Submit your Manuscript
SCImago Journal & Country Rank
Search
Editorial Policies
Sarajevo Declaration on Integrity and Visibility of Scholarly Publications

Open access

without publication fees
Share:
Send email
Share:
abstract:
Original paper

Exploring the potential synergistic pharmacological and psychological effects of caffeine on exercise performance: a placebo-balanced study

Juan Del Coso
1
,
Beatriz Lara
2, 3
,
César Gallo-Salazar
2, 3
,
Francisco Areces
2, 3
,
Millán Aguilar-Navarro
4
,
Verónica Giráldez-Costas
2, 3
,
Jorge Gutiérrez-Hellín
4
,
Fernando Valero
5
,
Juan Jose Salinero
2, 5

  1. Sport Sciences Research Centre, Rey Juan Carlos University, Fuenlabrada, Spain
  2. Exercise Physiology Laboratory (GIDECS) Faculty of Health Sciences – HM Hospitals, University Camilo José Cela, Villanueva de la Cañada, España
  3. Instituto de Investigación Sanitaria HM Hospitales, Madrid, Spain
  4. Faculty of Health Science, Universidad Francisco de Vitoria, Madrid, Spain
  5. Sport Training Laboratory (GIRD), Faculty of Sport Sciences, University of Castilla-La Mancha, Toledo, Spain
Biol Sport.2026; 43: 95–105
DOI: https://doi.org/10.5114/biolsport.2026.153332
Online publish date: 2025/08/05
View full text Get citation
 
PlumX metrics:
Research specifically investigating the distinct pharmacological and expectancy effects of caffeine using the deceptive placebo-balanced design remains scarce and with contradictory results. The aim of this study was to investigate the potential synergy between the pharmacological and expectancy effects of caffeine on exercise performance by using a placebo-balanced design. Sixteen physically trained athletes (11 males and 5 females; 21.7±5.0 yr) participated in a study with a deceptive protocol including four randomized conditions: placebo informed–placebo ingested (control); placebo informed–caffeine ingested (pharmacological effect); caffeine informed–placebo ingested (expectancy effect); and caffeine informed–caffeine ingested (combined effects). Sixty minutes after ingestion, participants performed a countermovement jump, a standing triple jump, a medicine ball throw and a 20-m running sprint test. Relative to control, the pharmacological effect trial increased standing triple jump distance (+2.1% p = 0.032; Cohen’s d= 0.59) and reduced 20-m sprint time (-0.8% p = 0.030; Cohen’s d= 0.60). The combined effect trial reduced 20-m sprint time (-0.8% p = 0.021; Cohen’s d= 0.64) in comparison to control. The expectancy effect trial did not modify performance in any of the performance tests with respect to control. When averaging the performance across all four tests, improvements relative to the control trial were +0.9%, +0.6% and +1.3% for pharmacological, expectancy and combined effects, respectively. The ingestion of caffeine, whether or not participants expected to receive it, improved exercise performance. This suggests that the primary driver of caffeine’s ergogenic effect is its pharmacological action, with only a minor contribution from expectancy.
keywords:

Placebo effect, Deception, Ergogenic aids, Nutrition, Sport supplements

  
Termedia
About us Contact
Copyright notice Privacy policy Advertising policy Contact us
Quick links
Journals Books eBooks Events
© 2025 Termedia Sp. z o.o.
Developed by Bentus.