High Dose of Caffeine Mouth Rinse Increases Resistance Training Performance in Men.

Raci Karayigit,Mitat Koz,Angela Sánchez-Gómez,Alireza Naderi,Fatih Gur,Raúl Domínguez,Ulas Can Yildirim

doi:10.3390/nu13113800

Abstract

Caffeine mouth rinsing (CMR) has been shown to enhance exercise performance. However, no studies have analyzed the effects of different dosages of CMR on muscular performance. Therefore, the purpose of this study was to examine the effects of different dosages of CMR on strength (bench press 1 repetition maximum (1-RM)) and muscular endurance (60% of 1-RM repetitions to failure) in resistance-trained males. Fourteen resistance-trained males (age: 23 ± 2 years, height: 179 ± 3 cm, body mass: 83 ± 4 kg, BMI: 17 ± 2 kg/m2) completed four conditions in random order. The four conditions consisted of a mouth rinse with 25 mL solutions containing either 1% (250 mg) of CMR (low dose of CMR: LCMR), 2% (500 mg) of CMR (moderate dose of CMR: MCMR), 3% (750 mg) of CMR (high dose of CMR: HCMR) and sweetened water (placebo: PLA) for 5 s prior to a bench press strength and muscular endurance test. Maximal strength, muscular endurance, heart rate (HR) and ratings of perceived exertion (RPE) were recorded for each condition. There were no significant differences in strength (p = 0.30) and HR (p = 0.83) between conditions. HCMR significantly increased muscular endurance performance (p = 0.01) and decreased RPE values (p = 0.01). In conclusion, CMR did not affect bench press 1-RM strength performance, but muscular endurance responses to CMR seems to be dose-dependent.

Highlights

Caffeine is one of the most used nutritional ergogenic aid by athletes [1] and considered effective in improving cardiorespiratory endurance [2], movement velocity [3], power [4] and muscular endurance during resistance exercises [5,6]
There was no main effect for condition (p = 0.30, η2 = 0.08) in 1-RM strength performance, meaning Caffeine mouth rinsing (CMR) did not affect this parameter (Figure 2)
Post hoc analysis revealed that HCMR has significantly higher repetition numbers compared to PLA (p = 0.03) and low dose of caffeine mouth rinse (LCMR) (p = 0.01)

Summary

Introduction

Caffeine is one of the most used nutritional ergogenic aid by athletes [1] and considered effective in improving cardiorespiratory endurance [2], movement velocity [3], power [4] and muscular endurance during resistance exercises [5,6]. Evidence still seems conflicting, with some research demonstrating no benefits in muscular strength [8] and endurance [9] performance after caffeine ingestion. Caffeine is generally consumed in moderate (3 mg/kg) to high (6 mg/kg) doses, with 9 mg/kg being uncommon [10]. Intake of caffeine might lead to some side effects during or after exercise, such as anxiety, headache, gastrointestinal discomfort and insomnia [12]. Alternative forms of caffeine usage that may mitigate its common side effects are relevant

Objectives

Methods

Results

Discussion

Conclusion