8 Ways Marijuana Affects The Body's Response To Exercise

There is a huge cultural shift taking place today as many states consider allowing the legal use of marijuana as a recreational drug. In 1996, California was the first state to allow the medicinal use of marijuana, and since then 24 other states and the District of Columbia have followed suit. Currently, four states allow the legal recreational use of marijuana, and nine more, including California, are set to vote on legalization in the 2016 election cycle.


From musicians and professional athletes to movie stars and politicians, the recreational use of marijuana is rapidly becoming an accepted component of mainstream culture. Let’s be perfectly clear, this blog is in no way advocating the use of marijuana, legal or otherwise. However, it looks like the number of states allowing the legal use of the drug is set to increase when we go to the polls this fall, making it necessary to have an open discussion on how the use of marijuana affects the body’s response to exercise.

As a health and fitness professional, you should understand how marijuana affects the human body, especially as it relates to exercise, so you can provide valid information and help educate your clients on how using the drug could impact their health. Like other substances such as alcohol, nicotine or caffeine, consuming too much marijuana could have negative health consequences and be a reason why a client may not be achieving his or her fitness goals. While each individual’s specific response to marijuana may vary, here are eight things to know about how this drug affects the body, each of which could have an impact on your client’s exercise program.


1. Marijuana stimulates hunger, which may lead to excessive caloric consumption and eventual weight gain. A client could burn hundreds of calories during an incredibly difficult high-intensity workout, but then offset that calorie burn by consuming a large quantity of fast food in response to an attack of “the munchies” after using marijuana at a social gathering.

2. Marijuana can increase feelings of anxiety, paranoia or depression so individuals should be aware that using marijuana could create unpredictable changes to their normal emotional state.

3. While marijuana can be ingested in an edible form, it is most commonly consumed via inhalation. Whether it is smoked in an unfiltered, hand-rolled cigarette, pipe, water pipe or vaporizer, inhaling marijuana smoke can cause irritation and inflammation of the lungs and bronchial tubes, which can reduce respiratory efficiency. Long-term exposure to marijuana smoke could cause respiratory problems and be a possible cause of lung cancer.

4. Marijuana has a drastic impact on motor skills. An individual under the influence of marijuana will experience changes in visual perception, coordination and reaction time, all of which can significantly impair his or her ability to exercise. If you suspect that a client is under the influence of marijuana, you should stop their participation in the workout immediately. Even if an individual states that he or she “feels fine,” they could risk serious injury if they exercise under the influence, and it is not worth testing your liability insurance.

5. Certain types of marijuana promote sleepiness and frequent use of marijuana may result in feelings of lethargy, which can drastically reduce an individual’s motivation for exercise.


6. Marijuana use can impair short-term memory, and long-term use could have a negative effect on overall cognitive function. There is a reason why the burned out, forgetful stoner stereotype exists and it is because frequent marijuana use can change how the brain works.

7. One possible side-effect of marijuana use is tachycardia, which is a rapid heartbeat that could be dangerous when combined with an elevated heart rate caused by exercise.

8. An individual who uses marijuana on a frequent basis can build up a tolerance to the effects of tetrahydrocannabinol (THC), which is the main psychoactive ingredient. This will require him or her to use greater amounts of the drug to experience the same effects. Regardless of whether it is legal or illegal, marijuana is expensive and frequent use could have a negative impact on an individual’s financial health (leaving less disposable income to be spent on health club dues and personal training fees).

While it may change in the elections this year, the recreational use of marijuana is still illegal in forty-six states. Although many states are changing their laws to allow legal possession or decriminalizing possession of small amounts, the federal government still considers marijuana to be a schedule one controlled substance and prosecutes individuals involved in the process of cultivation, distribution and sale of the drug. There may be many valid reasons why an individual chooses to use marijuana; the purpose of this blog is not to debate an individual’s decision to use the drug but simply to provide information on how it affects the body as it relates to exercise.