In an experiment, some volunteers were assigned to take aerobics classes and others to take weight-training classes  After three months, each performed an arduous mathematical calculation  Just after that challenge, the measurable stress symptoms of the volunteers in the aerobics classes were less than those of the volunteers in the weight-training classes
This provides good evidence that aerobic exercise helps the body handle psychological stress
Three months is enough time for the body to fully benefit from aerobic exercise.