Central effects of mouth rinses on endurance and strength performance
Document Type
Article
Publication Date
1-1-2024
Abstract
Rinsing the mouth with a carbohydrate (CHO) solution has been shown to enhance exercise performance while reducing neuromuscular fatigue. This effect is thought to be mediated through the stimulation of oral receptors, which activate brain areas associated with reward, motivation, and motor control. Consequently, corticomotor responsiveness is increased, leading to sustained levels of neuromuscular activity prior to fatigue. In the context of endurance performance, the evidence regarding the central involvement of mouth rinse (MR) in performance improvement is not conclusive. Peripheral mechanisms should not be disregarded, particularly considering factors such as low exercise volume, the participant's fasting state, and the frequency of rinsing. These factors may influence central activations. On the other hand, for strength-related activities, changes in motor evoked potential (MEP) and electromyography (EMG) have been observed, indicating increased corticospinal responsiveness and neuromuscular drive during isometric and isokinetic contractions in both fresh and fatigued muscles. However, it is important to note that in many studies, MEP data were not normalised, making it difficult to exclude peripheral contributions. Voluntary activation (VA), another central measure, often exhibits a lack of changes, mainly due to its high variability, particularly in fatigued muscles. Based on the evidence, MR can attenuate neuromuscular fatigue and improve endurance and strength performance via similar underlying mechanisms. However, the evidence supporting central contribution is weak due to the lack of neurophysiological measures, inaccurate data treatment (normalisation), limited generalisation between exercise modes, methodological biases (ignoring peripheral contribution), and high measurement variability. Trial registration: PROSPERO ID: CRD42021261714. Graphical abstract: The graphic depicts the main findings of the review and the benefits of MR on endurance and strength performance respectively. The figure also shows factors affecting MR response. TT Time trial, TTE Time to exhaustion, ISO-M Isometric contraction, ISO-K Isokinetic contraction, MR Mouth rinse (Figure presented.). © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023.
Keywords
Brain activation, Exercise performance, Mouth wash, Neurophysiological, Oral stimulation
Divisions
1234
Publication Title
European Journal of Applied Physiology
Volume
124
Issue
2
Publisher
Springer Science and Business Media Deutschland GmbH