Placebo in sports nutrition: a proof-of-principle study involving caffeine supplementation
Saunders B, Saunders B, de Oliveira LF, da Silva RP, de Salles Painelli V, Gonçalves LS, Yamaguchi G, Mutti T, Maciel E, Roschel H, Artioli GG, Gualano B
Scandinavian journal of medicine & science in sports · 140 citations
How it was studied
- Design
- Randomized controlled trial (indexed by PubMed)
- Studied in
- People
- Main outcome
- Health markers and function
Who paid for it
- Funding
- Independent funding
- Government
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Government
- Conselho Nacional de Desenvolvimento Científico e Tecnológico
- Grants
- Conselho Nacional de Desenvolvimento Científico e Tecnológico (150513/2015-1); Fundação de Amparo à Pesquisa do Estado de São Paulo (14/11948-8); Fundação de Amparo à Pesquisa do Estado de São Paulo (13/14746-4); Fundação de Amparo à Pesquisa do Estado de São Paulo (2013/04806-0); Fundação de Amparo à Pesquisa do Estado de São Paulo (2011/19513‐2)
Based on 2 listed funder(s).
Publication
- Published
- 2016-11-23 · Scand J Med Sci Sports · vol. 27 · issue 11 · pp. 1240–1247
- Publisher
- Wiley
- Cited
- 200 citations · more than 98% of similar papers · 8.3× the field average
- Impact
- Top 10% most cited in its field
- References
- 19 works
- Access
- Paywalled
- Research areas
- Muscle metabolism and nutrition · Pharmacology and Obesity Treatment · Coffee research and impacts
- Keywords
- Caffeine, Placebo, Medicine, Sports nutrition, Time trial, Physical therapy, VO2 max, Subgroup analysis, Sports medicine, Internal medicine, Athletes, Heart rate, Confidence interval
- MeSH
- humans, caffeine, exercise test, double-blind method, oxygen consumption, bicycling, dietary supplements, adult, male, athletic performance, performance-enhancing substances, sports nutritional physiological phenomena, proof of concept study
11 authors
From BR
- Bryan SaundersUniversidade de São Paulo
- Luana Farias de OliveiraUniversidade de São Paulo
- Rafael Pires da SilvaUniversidade de São Paulo
- Vítor de Salles PainelliUniversidade de São Paulo
- Lívia de Souza GonçalvesUniversidade de São Paulo
- Guilherme de Carvalho YamaguchiUniversidade de São Paulo
Abstract
We investigated the effects of supplement identification on exercise performance with caffeine supplementation. Forty-two trained cyclists (age 37 ± 8 years, body mass [BM] 74.3 ± 8.4 kg, height 1.76 ± 0.06 m, maximum oxygen uptake 50.0 ± 6.8 mL/kg/min) performed a ~30 min cycling time-trial 1 h following either 6 mg/kgBM caffeine (CAF) or placebo (PLA) supplementation and one control (CON) session without supplementation. Participants identified which supplement they believed they had ingested ("caffeine", "placebo", "don't know") pre- and post-exercise. Subsequently, participants were allocated to subgroups for analysis according to their identifications. Overall and subgroup analyses were performed using mixed-model and magnitude-based inference analyses. Caffeine improved performance vs PLA and CON (P ≤ 0.001). Correct pre- and post-exercise identification of caffeine in CAF improved exercise performance (+4.8 and +6.5%) vs CON, with slightly greater relative increases than the overall effect of caffeine (+4.1%). Performance was not different between PLA and CON within subgroups (all P > 0.05), although there was a tendency toward improved performance when participants believed they had ingested caffeine post-exercise (P = 0.06; 87% likely beneficial). Participants who correctly identified placebo in PLA showed possible harmful effects on performance compared to CON. Supplement identification appeared to influence exercise outcome and may be a source of bias in sports nutrition.
Abstract via Europe PMC. Copyright remains with the authors or publisher.
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