It is generally accepted that exercise reduces anxiety. However, some individuals feel more anxiety after exercising. This is not uncommon and can be remedied by recognizing what is causing the anxiety symptoms.
Shortness of Breath
When people exercise, they usually become somewhat short of breath. This is also a key symptom of anxiety. The brain may interpret the body being short of breath as an anxiety symptom, which can cause a secondary anxiety reaction, which is what happens when an individual responds to an anxiety trigger with anxious thoughts.
Heartrate also goes up when people exercise, just as it does when someone is experiencing an anxiety attack. People can have an anxiety attack after exercise if they believe that they are already beginning to have an attack. In this case, the fear of the attack causes one.
When people exercise, they sweat. Another common symptom of anxiety attacks is sweating. The sweating caused by exercise can be interpreted as the symptom of an anxiety attack.
People who experience fatigue as an anxiety symptom may be disconcerted when they are fatigued after a good workout. The fatigue from the workout may be indistinguishable from the fatigue caused by anxiety.
Low Blood Sugar
If individuals exercise without having eaten in a few hours, low blood sugar can result. Low blood sugar can mimic the symptoms of anxiety.
Gentle to moderate exercise burns off adrenaline. Strenuous exercise can cause the body to produce excess adrenaline, which can persist in the body for hours after exercise. According to a study published in Psychosomatic Medicine, adrenaline increases relative to effort expended during exercise. This adrenaline can cause anxiety.