The exact physiological mechanisms to explain how exercise improves stress have not been delineated. Human and animal research indicates that being physically active improves the way the body handles stress because of changes in the hormone responses, and that exercise affects neurotransmitters in the brain such as dopamine and serotonin that affect mood and behaviors (9,11). In addition to the possible physiological mechanisms, there also is the possibility that exercise serves as a time-out or break from one’s stressors. A study that tested the time-out hypothesis used a protocol that had participants exercise but did not allow a break from stress during the exercise session (5). Participants were college-aged women who reported that studying was their biggest stressor. Self-report of stress and anxiety symptoms was assessed with a standard questionnaire before and after four conditions over 4 days. The conditions were quiet rest, study, exercise, and studying while exercising. These conditions were counterbalanced across participants, and each condition was 40 minutes in duration. The “exercise only” condition had the greatest calming effect (5). When participants were not given a break from their stressor in the “studying while exercising” condition, exercise did not have the same calming effect.
Hi. This article contains a lot of information about brainwave entertainment. Thanks. I have a question. I downloaded an Android app that plays isochronic tones. I like to use an Isochronic tone at 2.5Hz that is in Delta range and is supposed to help me get a deep and dreamless sleep. I use it without headphones and just keep the smartphone next to my pillow. But I do not know if I should keep the tone playing all the time while I sleep or put it on timer to shut off after some specified time. A custom timer is possible with the app. Can you please guide me.
Much of what is currently written about brainwave entrainment, especially on the internet, is simply … incorrect.  It seems par for the course that when something of huge value is discovered as a potential ‘internet product’ that it is going to be marketed within an inch of it’s life. And often with less than stellar regard for actual science, research, or factual knowledge. 
As you close your eyes, this session quickly lulls you down into deep delta sleep, where the body recovers and grows. The session starts at a waking frequency, soon taking you down deep into delta, with stops at sigificant beneficial frequencies such as the de-stressing 10Hz, the grounding 7.83Hz Schumann resonance (SR), and the deeply relaxing 5.5Hz. You’ll soon find yourself in a deep, healing sleep. If you’re particularly stressed, try listening to Power Chill before starting