Dopamine and Muscle Function in the Heat
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|ClinicalTrials.gov Identifier: NCT03515668|
Recruitment Status : Unknown
Verified April 2018 by Stephen Cheung, Brock University.
Recruitment status was: Recruiting
First Posted : May 3, 2018
Last Update Posted : May 3, 2018
|Condition or disease||Intervention/treatment||Phase|
|Muscle Force Hyperthermia||Drug: Ritalin 20Mg Tablet Drug: Placebo Oral Tablet||Not Applicable|
Increased core temperature (hyperthermia) has been associated with impaired neuromuscular performance, with the majority of research suggesting that the observed fatigue is related to the central nervous system. Small doses of Ritalin has been used to study how changes in dopamine activity affects exercise capacity in the heat. This study found that 20 mg of Ritalin had no effect on exercise capacity in a thermoneutral environment of 18°C. However, when in a hot (30°C) environment, the Ritalin resulted in a 16% improvement in finishing time compared to the placebo trial. Interestingly, the higher output during the Ritalin-hot condition also resulted in higher rates of heat production and a higher (~0.6°C) core temperature, suggesting that dopamine enabled greater voluntary tolerance of hyperthermia. This matches recent work from our own work showing that motivational skills training increased both exercise tolerance and final core temperature, and it is possible that dopamine activity played a role in this improvement.
Ultimately, fatigue is shown in an inability to sustain muscular force. However, the role of dopamine activity on neuromuscular function (e.g., central activation and recruitment of muscle) during hyperthermia is unknown. One study reported that 20 mg of Ritalin did not alter neuromuscular function, but this study was done without thermal stress.
Therefore, our goal is to study the effects of dopamine activity, using Ritalin ingestion, on neuromuscular function over the course of a progressive heating and cooling protocol developed in our lab. We hypothesize that Ritalin will minimize the previously reported progressive impairment in neuromuscular function with hyperthermia (5, 7) compared to placebo, suggesting that dopamine activity preserves neuromuscular capacity with hyperthermia.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||14 participants|
|Intervention Model:||Single Group Assignment|
|Intervention Model Description:||Healthy males 18-30 years of age|
|Masking Description:||Double-blinding of participant and investigator, with independent investigator in charge of placebo and drug.|
|Primary Purpose:||Basic Science|
|Official Title:||The Influence of Dopamine Activity on Neuromuscular Function During Passive Heat Stress|
|Actual Study Start Date :||April 20, 2018|
|Estimated Primary Completion Date :||December 31, 2019|
|Estimated Study Completion Date :||December 31, 2019|
20 mg Ritalin, 90 min before testing
Drug: Ritalin 20Mg Tablet
Single dose for all participants
Placebo Comparator: Control
Identical size/taste placebo pill, 90 min before testing
Drug: Placebo Oral Tablet
Placebo with same appearance/taste
- Wrist flexion torque [ Time Frame: 2-4 hours after ingestion ]Maximal voluntary contraction of wrist flexion
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Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03515668
|Contact: Stephen S Cheung, PhD||9056885550 ext email@example.com|
|St Catharines, Ontario, Canada, L2S 3A1|
|Contact: Stephen Cheung, PhD 905 688-5550 ext 5662 firstname.lastname@example.org|