Athletic Performance
Conditions
Brief summary
Many different factors affect running performance, transcranial direct current stimulation (tDCS) is a widely used and available neuromodulation tool and could hypothetically facilitate the supraspinal drive and thereby act upstream of the motor cortex to prolong the muscles work in time to exhaustion trials. While it appears to decrease the rating of perceived exertion (RPE) during cycling, little is known about the effects of tDCS on physiological performance parameters such as maximal oxygen consumption (VO2max), maximal aerobic speed (MAS) and lactate thresholds in runners. The aim of this prospective randomized sham-controlled clinical trial is to investigate the physiological effects of tDCS applied over the motor cortex on perceived exertion and performance-related parameters measured by an incremental treadmill test to exhaustion. This research thus aims at answering the following questions: 1. Is active tDCS applied bilaterally over the motor cortex significantly more efficient than sham tDCS to improve the TTE? 2. Does active tDCS decreases the RPE, as compared to sham? 3. Is there any significant difference between active and sham tDCS on the physiological parameters measured during an incremental test to exhaustion, namely: VO2max, MAS, respiratory exchange ratio, blood lactate levels, maximal heart rate? 4. Does the baseline level of physical fitness influences response to tDCS? The investigators hypothesize that 1) performance as measured by time to exertion will be increased following active and not sham tDCS due to a decreased perceived rate of exertion without significantly altering the other physiological parameters; and 2) performance as measured by incremental treadmill test to exhaustion will be more improved in recreational as compared to trained runners.
Interventions
DEVICETranscranial Direct Current Stimulation (tDCS)
The active session of tDCS will consist in applying two anodes over M1 bilaterally (C3 and C4 according to the 10-20 international EEG placement) and the cathodes over the occipital areas (O1 and O2), and to inject 2 mA for 20 minutes through sponge electrodes (35 cm²) placed on the scalp using the Startsim 8 (Neuroelectrics, Barcelona). The sham tDCS will use the same montage and device but direct current will only be injected for 30 seconds, with a ramp-up and ramp-down 15 seconds period, to mimic the somatosensory effects of active tDCS.
Sponsors
University of Liege
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Intervention model description
Double-blind randomized sham controlled crossover
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy subject * Regular running activity above 2 hours/week * VO2max above 30 mL/min/kg
Exclusion criteria
* Pacemaker * Intracerebral metallic implant * Smoking * Using dietary supplementation or medication potentially affecting the CNS * Musculoskeletal injury within the past 6 weeks
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time to exertion (active vs. sham) | Immediate | Time to achieve exhaustion during a treadmill test where the speed is set at a constant 90% of the individual maximal aerobic speed (determined during the screening visit) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Ratings of perceived exertion (RPE) evolution (active vs. sham) | Every 3 minutes during the test to exhaustion until the end of the test (up to 1 hour after the stimulation) | RPE will be assessed continuously (every 3 minutes) during the time to exhaustion trial using the Borg rating of perceived exertion scale (RPE scale). The Borg RPE scale is a quantitative measure of perceived exertion during physical activity. The scale starts with no feeling of exertion, which rates a 6, and ends with very, very hard, which rates a 20. Moderate activities register 11 to 14 on the Borg scale (fairly light to somewhat hard), while vigorous activities usually rate a 15 or higher (hard to very, very hard). |
| Maximal Oxygen Consumption (VO2max) evolution (active vs. sham) | Immediate | VO2max will be assessed continuously during the time to exhaustion trial using a gas analyzer |
| Lactate thresholds (active vs. sham) | Every 3 minutes during the test to exhaustion until the end of the test (up to 1 hour after the stimulation) | Levels of blood lactate will be measured continuously (every 3 minutes) during the time to exhaustion trial using capillary blood and a lactate analyzer |
Countries
Belgium
Outcome results
None listed