Arthur Carvalho1, Felipe Miguel Marticorena1, Beatriz Helena Grecco1, Gabriel Barreto1, Bryan Saunders2,3. 1. Applied Physiology and Nutrition Research Group, School of Physical Education and Sport; Rheumatology Division, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455-Cerqueira César, São Paulo, SP, CEP 01246903, Brazil. 2. Applied Physiology and Nutrition Research Group, School of Physical Education and Sport; Rheumatology Division, Faculdade de Medicina FMUSP, Universidade de Sao Paulo, Av. Dr. Arnaldo, 455-Cerqueira César, São Paulo, SP, CEP 01246903, Brazil. drbryansaunders@outlook.com. 3. Institute of Orthopedics and Traumatology, Faculty of Medicine FMUSP, University of São Paulo, São Paulo, Brazil. drbryansaunders@outlook.com.
Abstract
OBJECTIVE: The aim was to quantify the proportion of the literature on caffeine supplementation that reports habitual caffeine consumption, and determine the influence of habitual consumption on the acute exercise response to caffeine supplementation, using a systematic review and meta-analytic approach. METHODS: Three databases were searched, and articles screened according to inclusion/exclusion criteria. Three-level meta-analyses and meta-regression models were used to investigate the influence of habitual caffeine consumption on caffeine's overall ergogenic effect and within different exercise types (endurance, power, strength), in men and women, and in trained and untrained individuals. Sub-analyses were performed according to the following: acute relative dose (< 3, 3-6, > 6 mg/kg body mass [BM]); whether the acute caffeine dose provided was lower or higher than the mean daily caffeine dose; and the caffeine withdrawal period prior to the intervention (< 24, 24-48, > 48 h). RESULTS: Sixty caffeine studies included sufficient information on habitual consumption to be included in the meta-analysis. A positive overall effect of caffeine was shown in comparison to placebo (standard mean difference [SMD] = 0.25, 95% confidence interval [CI] 0.20-0.30; p < 0.001) with no influence of relative habitual caffeine consumption (p = 0.59). Subgroup analyses showed a significant ergogenic effect when the caffeine dose was < 3 mg/kg BM (SMD = 0.26, 95% CI 0.12-0.40; p = 0.003) and 3-6 mg/kg BM (SMD = 0.26, 95% CI 0.21-0.32; p < 0.0001), but not > 6 mg/kg BM (SMD = 0.11, 95% CI - 0.07 to 0.30; p = 0.23); when the dose was both higher (SMD = 0.26, 95% CI 0.20-0.31; p < 0.001) and lower (SMD = 0.21, 95% CI 0.06-0.36; p = 0.006) than the habitual caffeine dose; and when withdrawal was < 24 h, 24-48 h, and > 48 h. Caffeine was effective for endurance, power, and strength exercise, with no influence (all p ≥ 0.23) of relative habitual caffeine consumption within exercise types. Habitual caffeine consumption did not modify the ergogenic effect of caffeine in male, female, trained or untrained individuals. CONCLUSION: Habitual caffeine consumption does not appear to influence the acute ergogenic effect of caffeine.
OBJECTIVE: The aim was to quantify the proportion of the literature on caffeine supplementation that reports habitual caffeine consumption, and determine the influence of habitual consumption on the acute exercise response to caffeine supplementation, using a systematic review and meta-analytic approach. METHODS: Three databases were searched, and articles screened according to inclusion/exclusion criteria. Three-level meta-analyses and meta-regression models were used to investigate the influence of habitual caffeine consumption on caffeine's overall ergogenic effect and within different exercise types (endurance, power, strength), in men and women, and in trained and untrained individuals. Sub-analyses were performed according to the following: acute relative dose (< 3, 3-6, > 6 mg/kg body mass [BM]); whether the acute caffeine dose provided was lower or higher than the mean daily caffeine dose; and the caffeine withdrawal period prior to the intervention (< 24, 24-48, > 48 h). RESULTS: Sixty caffeine studies included sufficient information on habitual consumption to be included in the meta-analysis. A positive overall effect of caffeine was shown in comparison to placebo (standard mean difference [SMD] = 0.25, 95% confidence interval [CI] 0.20-0.30; p < 0.001) with no influence of relative habitual caffeine consumption (p = 0.59). Subgroup analyses showed a significant ergogenic effect when the caffeine dose was < 3 mg/kg BM (SMD = 0.26, 95% CI 0.12-0.40; p = 0.003) and 3-6 mg/kg BM (SMD = 0.26, 95% CI 0.21-0.32; p < 0.0001), but not > 6 mg/kg BM (SMD = 0.11, 95% CI - 0.07 to 0.30; p = 0.23); when the dose was both higher (SMD = 0.26, 95% CI 0.20-0.31; p < 0.001) and lower (SMD = 0.21, 95% CI 0.06-0.36; p = 0.006) than the habitual caffeine dose; and when withdrawal was < 24 h, 24-48 h, and > 48 h. Caffeine was effective for endurance, power, and strength exercise, with no influence (all p ≥ 0.23) of relative habitual caffeine consumption within exercise types. Habitual caffeine consumption did not modify the ergogenic effect of caffeine in male, female, trained or untrained individuals. CONCLUSION: Habitual caffeine consumption does not appear to influence the acute ergogenic effect of caffeine.
Authors: Ronald J Maughan; Louise M Burke; Jiri Dvorak; D Enette Larson-Meyer; Peter Peeling; Stuart M Phillips; Eric S Rawson; Neil P Walsh; Ina Garthe; Hans Geyer; Romain Meeusen; Luc van Loon; Susan M Shirreffs; Lawrence L Spriet; Mark Stuart; Alan Vernec; Kevin Currell; Vidya M Ali; Richard G M Budgett; Arne Ljungqvist; Margo Mountjoy; Yannis Pitsiladis; Torbjørn Soligard; Uğur Erdener; Lars Engebretsen Journal: Int J Sport Nutr Exerc Metab Date: 2018-03-28 Impact factor: 4.599
Authors: B Saunders; L F de Oliveira; R P da Silva; V de Salles Painelli; L S Gonçalves; G Yamaguchi; T Mutti; E Maciel; H Roschel; G G Artioli; B Gualano Journal: Scand J Med Sci Sports Date: 2016-11-23 Impact factor: 4.221
Authors: J Mark Davis; Zuowei Zhao; Howard S Stock; Kristen A Mehl; James Buggy; Gregory A Hand Journal: Am J Physiol Regul Integr Comp Physiol Date: 2002-10-24 Impact factor: 3.619