Together with a healthy and balanced diet, regular exercise can reduce stress and give you a blissful state of mind that's hard to beat. Some may say marijuana can do that too, but mixing the two isn't a great idea. In the short term, it can detract from your physical performance and cloud your cognitive functions. In the long run, it dramatically increases your risk of having a heart attack or stroke.
Drag on the Brain
Smoking marijuana disrupts the area of your brain that handles coordination, perception and motor skills, reaction time and balance. Marijuana also impairs short-term memory and your ability to form new memories. That means you may also experience problems learning and remembering complex exercise routines that require skill and dexterity.
Effects on the Heart
Inhaling marijuana smoke can raise your blood pressure and almost double your heart rate. That leaves you open to a greater risk of heart attack or stroke. It'll also make it tougher for blood to carry oxygen to your muscles and vital organs, such as the heart and brain. This increased strain on your vascular system will lead to shortness of breath and sap your physical ability to keep up with others.
Doping and Intoxication
As outlined by the California Society of Addiction Medicine, marijuana can trigger feelings of euphoria and at the same time, reduce anxiety by relaxing your body. Because of this, you may feel less inclined to push yourself and compete with others in group exercise or team sports. You may also experience mild intoxication and drowsiness. That's not a good way to exercise safely and effectively, either on your own or with other people.
Lack of Motivation
A study by scientists at Imperial College London, University College London (UCL) and King’s College London in 2006 found dopamine levels in the brain were lower among people who smoked marijuana. Dopamine has been linked to levels of motivation. This means smoking marijuana could leave you feeling less motivated to take part in regular physical exercise.