Challenging the Myth of Non-Response to the Ergogenic Effects of Caffeine Ingestion on Exercise Performance.

Juan Del Coso,Carlos Ruiz-Moreno,Juan Salinero,Beatriz Lara

doi:10.3390/nu11040732

Abstract

The ergogenicity of caffeine on several exercise and sport situations is well-established. However, the extent of the ergogenic response to acute caffeine ingestion might greatly vary among individuals despite using the same dosage and timing. The existence of one or several individuals that obtained minimal ergogenic effects or even slightly ergolytic effects after caffeine intake (i.e., non-responders) has been reported in several previous investigations. Nevertheless, the concept non-responding to caffeine, in terms of physical performance, relies on investigations based on the measurement of one performance variable obtained once. Recently it has been suggested that correct identification of the individual ergogenic effect induced by caffeine intake requires the repeated measurement of physical performance in identical caffeine–placebo comparisons. In this communication, we present data from an investigation where the ergogenic effect of acute caffeine intake (3 mg/kg) was measured eight times over a placebo in the same individuals and under the same conditions by an incremental cycling test to volitional fatigue and an adapted version of the Wingate cycling test. The ergogenic response to caffeine varied from 9% to 1% among individuals, but all participants increased both cycling power in the incremental test and Wingate mean power at least three to eight times out of eight the caffeine–placebo comparisons. These data expand the suggestion of a minimal occurrence of caffeine non-responders because it shows that all individuals responded to caffeine when caffeine is compared to a placebo on multiple and repeated testing sessions.

Highlights

2018 has been a prolific year for the publication of manuscripts aimed at explaining the causes of the interindividual variations for the ergogenic response of caffeine ingestion on exercise performance.we read with interest the reviews by Southward et al [1] and Fulton et al [2] and the letter by Grgic [3], published in Nutrients in 2018, because they offered new insights towards unveiling the causes of the variability on physiological responses to caffeine
The data provided in this communication do not dispute the existence of a great interindividual variability to the ergogenic effects of caffeine ingestion, nor the genetic, environmental, In conclusion, the data provided in this communication do not dispute the existence of a great or epigenetic causes associated to this variability
This analysis suggests that individuals, interindividual variability to the ergogenic effects of caffeine ingestion, norall the genetic, to some extent, positively respond to the acute ingestion of mg/kg of caffeine, while the magnitude of environmental, or epigenetic causes associated to this variability

Summary

Introduction

2018 has been a prolific year for the publication of manuscripts aimed at explaining the causes of the interindividual variations for the ergogenic response of caffeine ingestion on exercise performance. We read with interest the reviews by Southward et al [1] and Fulton et al [2] and the letter by Grgic [3], published in Nutrients in 2018, because they offered new insights towards unveiling the causes of the variability on physiological responses to caffeine With this communication, we want to expand the understanding about why some individuals obtain less ergogenic benefits after the ingestion of a moderate dose of caffeine than others, and perhaps it will help to dispel the myth/concept of non-responders to caffeine, at least when referring to exercise performance

Individual Responses to Ergogenic Effects of Caffeine Ingestion

Conclusions