scholarly journals Transcranial direct current stimulation does not enhance cycling time-trial performance

2019 ◽  
Author(s):  
Justin Andre ◽  
Ann-Maree Vallence ◽  
Hakuei Fujiyama ◽  
Jeremiah Peiffer
Keyword(s):  
Direct Current ◽  
Power Output ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Time Trial ◽  
Cycling Performance ◽  
Time To Exhaustion ◽  
Mean Power ◽  
Mean Values ◽  
Direct Current Stimulation

Transcranial direct current stimulation (tDCS) to the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC) have separately been shown to increase performance during fixed-work time-to-exhaustion tasks. No studies have examined application of tDCS to these cortical sites in a single study or during self-paced tasks. Objectives: This study examined the influence of anodal-tDCS (A-tDCS) applied to M1 and DLPFC on cycling performance during a self-paced 16.1-km time trial (TT). Design: randomised cross-over design. Methods: Ten cyclists received 20 min of A-tDCS (1.5 mA) applied to M1, DLPFC or the visual cortex (V1; control), followed by a standardised 10-min warmup and a 16.1-km cycling TT. During the TT, heart rate and power output were continuously recorded and mean values for each quartile of the total TT duration were calculated. Ratings of perceive exertion (RPE) were collected at four, eight, 12 and 16.1 km. RESULTS: No differences were observed for the time-to-complete (p=0.07; BF10=1.24) or mean power output (p=0.09; BF10=1.11) during the 16.1-km TT between the M1 (1443.7±81.0 s and 274±44 W), DLPFC (1428.4±80.0 s and 280±39 W) and V1 (1434.8±9.6 s and 279±44 W) conditions. Both HR and RPE progressively increased from the first quartile of the TT with no differences observed between A-tDCS conditions. CONCLUSION: A-tDCS does not represents a viable method to decrease the physiological and perceptual stress during or enhance the performance of a self-paced cycling TT. Nevertheless, these findings should be viewed with respect to the inherent complexities between performance, fatigue and the brain.

scholarly journals Transcranial direct current stimulation (tDCS) over the left prefrontal cortex does not affect time-trial self-paced cycling performance: Evidence from oscillatory brain activity and power output

2018 ◽  
Author(s):  
Darías Holgado ◽  
Thomas Zandonai ◽  
Luis F. Ciria ◽  
Mikel Zabala ◽  
James Hopker ◽  
...  
Keyword(s):  
Heart Rate ◽  
Prefrontal Cortex ◽  
Direct Current ◽  
Power Output ◽  
Transcranial Direct Current Stimulation ◽  
Brain Activity ◽  
Time Trial ◽  
Maximal Power Output ◽  
Direct Current Stimulation ◽  
Oscillatory Brain Activity

AbstractObjectivesTo test the hypothesis that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) influences performance in a 20-min time-trial self-paced exercise and electroencephalographic (EEG) oscillatory brain activity in a group of trained male cyclists.DesignThe study consisted of a pre-registered (https://osf.io/rf95j/), randomised, sham-controlled, single-blind, within-subject design experiment.Methods36 trained male cyclists, age 27 (6.8) years, weight 70.1 (9.5) Kg; VO2max: 54 (6.13) ml.min−1.kg−1, Maximal Power output: 4.77 (0.6) W/kg completed a 20-min time-trial self-paced exercise in three separate sessions, corresponding to three stimulation conditions: anodal, cathodal and sham. tDCS was administered before each test during 20-min at a current intensity of 2.0 mA. The anode electrode was placed over the DLPFC and the cathode in the contralateral shoulder. In each session, power output, heart rate, sRPE and EEG (at baseline and during exercise) was measured.ResultsThere were no differences (F = 0.31, p > 0.05) in power output between the stimulation conditions: anodal (235 W [95%CI 222 - 249 W]; cathodal (235 W [95%CI 222 - 248 W] and sham (234 W [95%CI 220 - 248 W]. Neither heart rate, sRPE nor EEG activity were affected by tDCS (all Ps > 0.05).ConclusiontDCS over the left DLFC did not affect self-paced exercise performance in trained cyclists. Moreover, tDCS did not elicit any change on oscillatory brain activity either at baseline or during exercise. Our data suggest that the effects of tDCS on endurance performance should be taken with caution.

scholarly journals Transcranial Direct Current Stimulation Enhances Muscle Strength of Non-dominant Knee in Healthy Young Males

2021 ◽  
Vol 12 ◽  
Author(s):  
Panpan Lu ◽  
Nicholas J. Hanson ◽  
Lin Wen ◽  
Feng Guo ◽  
Xiaoyu Tian
Keyword(s):  
Muscle Strength ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Knee Extensors ◽  
Mean Power ◽  
Root Mean Square Amplitude ◽  
Mean Power Frequency ◽  
Sham Stimulation ◽  
Direct Current Stimulation

Transcranial direct current stimulation (tDCS) has been applied in training and competition, but its effects on physical performance remain largely unknown. This study aimed to observe the effect of tDCS on muscular strength and knee activation. Nineteen healthy young men were subjected to 20 min of real stimulation (2 mA) and sham stimulation (0 mA) over the primary motor cortex (M1) bilaterally on different days. The maximal voluntary contraction (MVC) of the knee extensors and flexors, and surface electromyography (sEMG) of the rectus femoris (RF) and biceps femoris (BF) were recorded before, immediately after, and 30 min after stimulation. MVC, rate of force development (RFD), and sEMG activity were analyzed before and after each condition. MVC of the non-dominant leg extensor and flexor was significantly higher immediately after real stimulation and 30 min after stimulation than before, and MVC of the non-dominant leg flexor was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). The RFD of the non-dominant leg extensor and flexor immediately after real stimulation was significantly higher than before stimulation, and the RFD of the non-dominant leg extensor immediately after real stimulation and 30 min after stimulation was significantly higher than that of sham stimulation (P < 0.05). EMG analysis showed the root mean square amplitude and mean power frequency (MPF) of the non-dominant BF and RF were significantly higher immediately after real stimulation and 30 min after stimulation than before stimulation, and the MPF of the non-dominant BF EMG was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). Bilateral tDCS of the M1 can significantly improve the muscle strength and explosive force of the non-dominant knee extensor and flexor, which might result from increased recruitment of motor units. This effect can last until 30 min after stimulation, but there is no significant effect on the dominant knee.

scholarly journals Improving Cycling Performance: Transcranial Direct Current Stimulation Increases Time to Exhaustion in Cycling

PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0144916 ◽  
Author(s):  
Marcelo Vitor-Costa ◽  
Nilo Massaru Okuno ◽  
Henrique Bortolotti ◽  
Maurizio Bertollo ◽  
Paulo Sergio Boggio ◽  
...  
Keyword(s):  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Cycling Performance ◽  
Time To Exhaustion ◽  
Direct Current Stimulation

scholarly journals Transcranial Direct Current Stimulation Enhances Muscle Strength of Non-dominant Knee in Healthy Young Males

2021 ◽  
Author(s):  
PanPan Lu ◽  
Nicholas J. Hanson ◽  
Lin Wen ◽  
Feng Guo
Keyword(s):  
Muscle Strength ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Knee Extensors ◽  
Mean Power ◽  
Root Mean Square Amplitude ◽  
Young Males ◽  
Sham Stimulation ◽  
Direct Current Stimulation

Abstract Background: Transcranial direct current stimulation (tDCS) has been applied in training and competition, but its effects on physical performance remain largely unknown. The present study aimed to observe the effect of tDCS on muscular strength and activation of the knee in healthy subjects. Methods: Nineteen healthy young males were subjected to 20 min real stimulation (2 mA) and sham stimulation (0 mA) on different days. The maximal voluntary contraction (MVC) of knee extensors and flexors and surface electromyography (sEMG) of the rectus femoris (RF) and biceps femoris (BF) were recorded before, immediately after, and 30 min after stimulation. MVC, rate of force development (RFD), and sEMG activity were analyzed before and after each condition. Results: MVC of left leg extensor and flexor was significantly higher immediately after real stimulation and 30 min after stimulation than before, and MVC of left leg flexor was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). The RFD of left leg extensor and flexor immediately after real stimulation was significantly higher than before stimulation, and the RFD of left leg extensor immediately after real stimulation and 30 min after stimulation was significantly higher than that of sham stimulation (P < 0.05). EMG analysis showed the root mean square amplitude(RMS) and mean power frequency (MPF) of left BF and RF were significantly higher immediately after real stimulation and 30 min after stimulation than before stimulation, and the MPF of left BF EMG was significantly higher 30 min after real stimulation than that after sham stimulation (P < 0.05). Conclusions: Bilateral tDCS of the primary motor cortex can significantly improve the muscle strength and explosive force of the non-dominant knee extensor and flexor, which is manifested by the increase of the amount of motor units recruited during exercise. This effect can last until 30 min after stimulation, but there is no significant effect on the dominant knee.

scholarly journals Comparison of repeated transcranial stimulation and transcranial direct-current stimulation on primary motor cortex excitability and inhibition: A pilot study

2018 ◽  
pp. 59-67 ◽  
Author(s):  
Vincent Cabibel ◽  
Makii Muthalib ◽  
Jérôme Froger ◽  
Stéphane Perrey
Keyword(s):  
Pilot Study ◽  
Motor Cortex ◽  
Direct Current ◽  
Transcranial Direct Current Stimulation ◽  
Primary Motor Cortex ◽  
Motor Evoked Potentials ◽  
High Definition ◽  
Direct Current Stimulation ◽  
Motor Cortex Excitability ◽  
The Right

Repeated transcranial magnetic stimulation (rTMS) is a well-known clinical neuromodulation technique, but transcranial direct-current stimulation (tDCS) is rapidly growing interest for neurorehabilitation applications. Both methods (contralesional hemisphere inhibitory low-frequency: LF-rTMS or lesional hemisphere excitatory anodal: a-tDCS) have been employed to modify the interhemispheric imbalance following stroke. The aim of this pilot study was to compare aHD-tDCS (anodal high-definition tDCS) of the left M1 (2 mA, 20 min) and LF-rTMS of the right M1 (1 Hz, 20 min) to enhance excitability and reduce inhibition of the left primary motor cortex (M1) in five healthy subjects. Single-pulse TMS was used to elicit resting and active (low level muscle contraction, 5% of maximal electromyographic signal) motor-evoked potentials (MEPs) and cortical silent periods (CSPs) from the right and left extensor carpi radialis muscles at Baseline, immediately and 20 min (Post-Stim-20) after the end of each stimulation protocol. LF-rTMS or aHD-tDCS significantly increased right M1 resting and active MEP amplitude at Post-Stim-20 without any CSP modulation and with no difference between methods. In conclusion, this pilot study reported unexpected M1 excitability changes, which most likely stems from variability, which is a major concern in the field to consider.

scholarly journals The effects of transcranial direct current stimulation on objective and subjective indexes of exercise performance: a systematic review and meta-analysis.

2018 ◽  
Author(s):  
Darias Holgado ◽  
Miguel A. Vadillo ◽  
Daniel Sanabria
Keyword(s):  
Systematic Review ◽  
Direct Current ◽  
Exercise Performance ◽  
Transcranial Direct Current Stimulation ◽  
Perceived Exertion ◽  
Effect Sizes ◽  
Electrode Placement ◽  
Current Evidence ◽  
Time To Exhaustion ◽  
Direct Current Stimulation

Objective: To examine the effectss of transcranial direct current stimulation (tDCS) on objective and subjective indexes of exercise performance.Design: Systematic review and meta-analysis.Data Sources: A systematic literature search of electronic databases (PubMed, Web of Science, Scopus, Google Scholar) and reference lists of included articles up to June 2018.Eligibility Criteria: Published articles in journals or in repositories with raw data available, randomized sham-controlled trial comparing anodal stimulation with a sham condition providing data on objective (e.g. time to exhaustion or time-trial performance) or subjective (e.g. rate of perceived exertion) indexes of exercise performance.Results: The initial search provided 420 articles of which 31 were assessed for eligibility. Finally, the analysis of effect sizes comprised 24 studies with 386 participants. The analysis indicated that anodal tDCS had a small but positive effect on performance g = 0.34, 95% CI [0.12, 0.52], z = 3.24, p = 0.0012. Effects were not significantly moderated by type of outcome, electrode placement, muscles involved, number of sessions, or intensity and duration of the stimulation. Importantly, the funnel plot showed that, overall, effect sizes tended to be larger in studies with lower sample size and high standard error. Summary: The results suggest that tDCS may have a positive impact on exercise performance. However, the effect is probably small and most likely biased by low quality studies and the selective publication of significant results. Therefore, the current evidence does not provide strong support to the conclusion that tDCS is an effective means to improve exercise performance.

scholarly journals The Ingestion of 39 or 64 g·hr−1 of Carbohydrate is Equally Effective at Improving Endurance Exercise Performance in Cyclists

2015 ◽  
Vol 25 (3) ◽  
pp. 285-292 ◽  
Author(s):  
Michael L. Newell ◽  
Angus M. Hunter ◽  
Claire Lawrence ◽  
Kevin D. Tipton ◽  
Stuart D. R. Galloway
Keyword(s):  
Power Output ◽  
Statistical Significance ◽  
Time Trial ◽  
Cycling Performance ◽  
Constant Load ◽  
Peak Power Output ◽  
Task Completion ◽  
Intake Rate ◽  
Mean Power ◽  
Pacing Strategy

In an investigator-blind, randomized cross-over design, male cyclists (mean± SD) age 34.0 (± 10.2) years, body mass 74.6 (±7.9) kg, stature 178.3 (±8.0) cm, peak power output (PPO) 393 (±36) W, and VO2max 62 (±9) ml·kg−1min−1 training for more than 6 hr/wk for more than 3y (n = 20) completed four experimental trials. Each trial consisted of a 2-hr constant load ride at 95% of lactate threshold (185 ± 25W) then a work-matched time trial task (~30min at 70% of PPO). Three commercially available carbohydrate (CHO) beverages, plus a control (water), were administered during the 2-hr ride providing 0, 20, 39, or 64g·hr−1 of CHO at a fluid intake rate of 1L·hr−1. Performance was assessed by time to complete the time trial task, mean power output sustained, and pacing strategy used. Mean task completion time (min:sec ± SD) for 39g·hr−1 (34:19.5 ± 03:07.1, p = .006) and 64g·hr−1 (34:11.3 ± 03:08.5 p = .004) of CHO were significantly faster than control (37:01.9 ± 05:35.0). The mean percentage improvement from control was −6.1% (95% CI: −11.3 to −1.0) and −6.5% (95% CI: −11.7 to −1.4) in the 39 and 64g·hr−1 trials respectively. The 20g·hr−1 (35:17.6 ± 04:16.3) treatment did not reach statistical significance compared with control (p = .126) despite a mean improvement of −3.7% (95% CI −8.8−1.5%). No further differences between CHO trials were reported. No interaction between CHO dose and pacing strategy occurred. 39 and 64g·hr−1 of CHO were similarly effective at improving endurance cycling performance compared with a 0g·hr−1 control in our trained cyclists.

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