Neurophysiological Reserve With Caffeine Manipulation

Caffeine Clinical Trial

Official title: Neurophysiological Reserve: Peripheral and Central Effects of Caffeine Manipulation

Status Completed

Clinical Trial Summary

The objective of this study is to verify if there is a neurophysiologic reserve when caffeine and placebo perceived as caffeine are manipulated in closed- and opened-loop exercises. Parameters of excitability level of skeletal muscle and Central Nervous System (CNS), and peripheral metabolism will be measured

Clinical Trial Description

A neurophysiological reserve related to central mechanisms is supposed to be present, which should be observed when an increased central drive occurs. In theory, according to the central regulation model of effort, an increased performance could be due to the elevation on Central Nervous System excitability and activity, since exercise is not peripherally limited. Conversely, the absence of muscle performance improvement to the increased central drive promoted by caffeine would be an evidence for a peripherally localized neurophysiological limit and would indicate the absence of reserve. Therefore, if present, this reserve could be verified by using peripheral and central measures derived from electric-stimulation, evoked twitch and interpolated twitch techniques, associated to measures of EMG and peripheral metabolism, when caffeine is manipulated during closed- and opened-loop exercise.

In addition, there should also be possible to access the reserve without stimulant substance manipulation (placebo effect). By teleological argument derived from the central regulation model of effort, a neurophysiological reserve would be a natural mechanism to protect the cellular integrity. Therefore, it would be reasonable to hypothesize that, if present, a reserve would be observed by an increase in performance promoted by an elevation in central drive when placebo is perceived as caffeine. Unfortunately, however, no study utilized this experimental approach, including measures of central and peripheral activity during closed- and opened-loop exercise, to consistently respond the reserve question. ;

Study Design

Allocation: Randomized, Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Caffeine
• Placebo

• NCT number: NCT01167478
• Study type: Interventional
• Source: University of Sao Paulo
• Status: Completed
• Phase: N/A
• Start date: March 2011
• Completion date: September 2011