Effect of Increased Pain Tolerance on Exercise Performance

Study Overview
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Brief Summary
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Clinical prescription and use of opioids is a clear problem in large parts of the world and has the recent years received an increasing publicity in sports. This is in particular due to the World Anti-Doping Agency monitoring list, which reveal that endurance athletes utilize the opioid Tramadol frequently with the aim to enhance performance according to anecdotal evidence. Studies investigating the effect of tramadol on exercise performance in healthy humans is limited to one study in moderate trained subjects. However, this effect may be different in highly trained subjects due to the effects of chronic exercise. Furthermore, ingestion of tramadol may impact motor-cognitive performance and it remains unknown whether tramadol can be detected in highly trained subjects following exercise. In the present study the investigators apply a randomized double-blind placebo-controlled counterbalanced cross-over design to investigate whether tramadol treatment improves a preloaded cycling time trial performance, whether it affects motor-cognitive performance and whether it is detectable following exercise.

Official Title
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Effect of Increased Pain Tolerance on Exercise Performance

Conditions
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Opioid Use, Exercise

Intervention / Treatment
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* Drug: Tramadol
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Maximal oxygen uptake < 55 ml O2/min/kg Plasma creatinine concentration between 60-105 umol/L Plasma alanine aminotransferase between 10-70 U/L Familiarized with endurance training for at least a few years Exclusion Criteria: Donated blood within the last 3 months Exposed to an altitude greater than 1000 m above sea level within the last two months Smoking

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 39 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Tramadol treatment<br> | Drug: Tramadol<br>* The subjects will orally ingest 100 mg tramadol retard actavis<br>|
| Placebo Comparator: Placebo treatment<br> | Other: Placebo<br>* The subjects will orally ingest 100 mg calcium powder<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Power output | Mean power output during a 15-km time trial | 30 minutes | 
| Motor-cognitive performance | The motor-cognitive performance evaluated by mathematical calculations combined with the ability to pinch a certain force with the thumb and index finger | 1 hour | 
| Detection rate | The detection rate of tramadol following the exercise intervention measured before, immediately after as well as 6 and 24h after treatment | 1 day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| pH | The response of blood pH to exercise performance | 90 min | 
| Lactate | The response of blood lactate to exercise performance | 90 min | 
| Bicarbonate | The response of blood bicarbonate to exercise performance | 90 min | 
| Glucose | The response of blood glucose to exercise performance | 90 min | 
| Potassium | The response of blood potassium to exercise performance | 90 min | 
| Sodium | The response of blood sodium to exercise performance | 90 min | 
| Oxygen uptake | The response of systemic oxygen uptake during exercise performance | 90 min | 
| Pulmonary ventilation | The response of pulmonary ventilation during exercise performance. | 90 min | 
| Respiratory exchange ratio | The response of respiratory exchange ratio during exercise performance, calculated as the ratio between system oxygen uptake and systemic carbon monoxide production. The unit of measure is arbitrary. | 90 min | 
| Rate of Perceived Exertion | Measurement of the rate of perceived exertion by questionnaire during exercise performance using The borg scale of perceived exertion, which range from 6 (minimum value) to 20 (maximum value). Higher values represent a higher perceived exertion. | 90 min | 
| Leg Pain | Measurement of the leg pain by questionnaire during exercise performance using the 10-point pain scale, which range from 0 (minimum) to 10 (maximum). Higher values represent a higher pain. | 90 min | 
| Heart rate | The response of heart rate to exercise performance | 90 min | 
| Power output during preload | Mean power output during a 60-min cycling exercise | 60 min | 
| Power output during time trial | The power output measured for each km of the time trial | 30 min |