Acute effects of marihuana smoking on maximal exercise performance

Med Sci Sports Exerc. 1986 Dec;18(6):685-9.


To evaluate the effects of marihuana smoking on exercise performance, 12 healthy young subjects did progressive exercise testing on an ergocycle to exhaustion under two conditions: non-smoking (control) and 10 min after smoking a marihuana cigarette (containing 1.7% of delta-9-tetra-hydro-cannabinol) of 7 mg X kg-1 body weight. Heart rate, arterial blood pressure, minute ventilation (VE), breathing rate (fb), oxygen uptake (VO2), and carbon dioxide output (VCO2) were measured before, during, and for 4 min after the exercise. Tidal volume was calculated from VE X fb-1. The exercise duration was also measured. Forced expiratory volume (FEV1) was measured: before smoking (rest); before exercise (10 min after smoking); and after exercise. Carboxyhemoglobin levels were measured before and 10 min after smoking in four subjects. Marihuana smoking reduced exercise duration (16.1 +/- 4.0 to 15.1 +/- 3.3 min, P less than 0.05). At peak exercise performance, there were no differences in VO2, VCO2, heart rate, and VE between the two experimental conditions. Marihuana induced tachycardia at preexercise (94.3 +/- 13.3 beats X min-1 to 119.0 +/- 18.0, P less than 0.01) that was sustained up to 80% of maximum effort and during the recovery period. After marihuana, VE, VO2 and VCO2 were increased above control from 50% of maximum effort to the end of the test. Marihuana induced a bronchodilation (FEV1 from 4.28 +/- 1.00 to 4.43 +/- 1.031, P less than 0.0) that was still present after exercise. Exercise induced a bronchodilation in the control condition but not in the marihuana smoking condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Pressure
  • Bronchi / physiopathology
  • Carbon Dioxide / metabolism
  • Dilatation, Pathologic / etiology
  • Energy Metabolism
  • Female
  • Heart Rate
  • Humans
  • Male
  • Marijuana Abuse / complications
  • Marijuana Abuse / physiopathology*
  • Oxygen Consumption
  • Physical Exertion*
  • Respiratory Function Tests
  • Tachycardia / etiology
  • Work Capacity Evaluation


  • Carbon Dioxide