But here is where I’d like to chime in my own two cents.  As a user of brainwave entrainment products for over 8 years now, you would obviously have to guess that I think this technology is fabulous.  Even my earlier experiences with brainwave entrainment technology using less refined binaural beats were nothing short of miraculous for me.  It’s a very fascinating experience to go from not being able to meditate at all to being able to sit with your eyes closed and headphones on and effortlessly slip down into deep brainwave states that were previously only reserved for years-long experienced meditators.
To summarize all this, we can see that the type of product you choose plays an important role in answering that question – “Can brainwave entrainment damage my brain?” My personal advice as a long-term user of the technology is to Be selective about what brainwave entrainment audios you download from the internet, and make sure to follow the instructions! 
These are lower frequency waves: The state is generated when our thoughts are really not concentrated and our minds wander freely, or we are in a relaxed state such as meditating or daydreaming. We also experience Alpha Brainwaves when we are gently busy with routine tasks like pottering in the garden, taking a shower, putting on makeup, doing light housework. Alpha is considered to be the bridge between the conscious mind and the subconscious mind.
Hi EJ, at the moment, there hasn’t been any research to give an indication of how long you should or shouldn’t listen for. Over time, I’ve seen people use my tracks for longer and longer. I started off providing 30-minute study tracks, but through demand, I extended them to 3-hours. I know from the many thousands of comments I’ve had on YouTube that a large number of people play those 3-hour tracks on repeat, or listen to different ones, one after the other throughout the day. I’ve also seen apps where you can play tracks like mine on continuous repeat. So it’s common for people to listen to them all day while they are studying.
If you've heard of or used other brainwaves entrainment such as Holosync®, Hemi-Sync®, Brainsync®, Brainwave Generator, Awakened Mind System, NeuroProgrammer™, LifeFlow™, The Morry Method™, Brain Evolution System™, Perfect Meditation, EquiSync® or iNet™, it is important to understand that NeuralSync™ is significantly different and superior to all of them. It is light years beyond traditional sound therapy like binaural beats, isochronic tones or typical meditation programs.
Alpha (12hz – 8hz) – Awake, but deeply relaxed. Simply closing your eyes will produce alpha brainwaves. This category is associated with daydreaming, visualization, imagination, light meditation. Brainwave expert Anna Wise called the alpha range the bridge between beta and theta. (More information can be found in Wise’ book The High-Performance Mind)
 It is a good idea to follow any instructions outlined by the makers of any type of brainwave entrainment product or program, and to ease yourself carefully into using it. If experiencing any negative side effects, take a break and come back to it later. Brainwave entrainment audios are not recommended for children under the age of 18, and should not be used while driving or operating heavy machinery.
This music encourages a state of alpha relaxation. The alpha state is a pleasant state of relaxed alertness. It’s a state that many people experience when they are waking up in the morning or when they are just beginning to drift off to sleep at night. While in a state of alpha relaxation, the mind is quite clear and receptive to information, learning is accelerated and one’s sense of creativity is enhanced. The mind is also very open to positive suggestions during this state.

Our brains follow cues from outside stimuli, and brainwaves mimic the pulse rates of the sounds we expose it to. So, by creating tracks that pulse sound waves at a desired frequency, we can effectively coax our brain into that state. In layman's terms; by listening to some strange sounding brainwave frequency audios, we can literally slip our brain into a state of feeling calm, alert, focused, energized... and the list goes on. Pretty cool, right!?

I haven’t seen any research relating to using brainwave entrainment/isochronic tones and bodybuilding, so I’m afraid I don’t know how effective it would be to help with that. I have a few different tracks for increasing energy but I recommend this 1-hour track, which would fit better than my shorter tracks for a training session: https://www.mindamend.com/shop/energy-and-motivation/high-energy-builder/. The effects from these tracks are mainly felt while you listen to them, so I recommend listening to the energy tracks while you are training/lifting weights etc. I don’t currently have any tracks to help trigger the testosterone hormone.

- Added the ability to create a playlist of your own iTunes library music and use it as the background. The behavior of the app when iTunes music is used instead of the included ambience is slightly different so please review the help. Notably, unlike our included ambience which can be played at a volume below the device volume, iTunes music can only be played at the device volume. So when playing iTunes music the Ambience volume slider disappears.

“A quite different phenomenon results when stereophonic earphones are used and the signals are applied separately to each ear. Under the right circumstances beats can be perceived, but they are of an entirely different character. They are called binaural beats. . . . Binaural beats require the combined action of both ears. They exist as a consequence of the interaction of perceptions within the brain.”
If you're struggling to focus and feeling a bit tired and unmotivated while studying, you can help boost your concentration and energy levels by increasing Beta activity.  The SMR range is right at the bottom of the Beta range, so it's not too intense, and so is ideal for playing in the background and using as a general study aid.  If you are looking for something a bit higher for a more intense focus session, try my Study Focus isochronic tones session, which uses frequencies between 14-17Hz.
Beta is the most common brain wave pattern: Beta brainwaves are produced when we are wide awake, alert, active and engaged in mental activity, usually involving more the rational, reality-oriented left hemisphere of our brain. When beta wave activity becomes very intense, our brain hemispheres become less synchronised. Beta state is required to function properly in your everyday life.
When the brain is stimulated with pulsed sounds (neuroelectrical activity via the nerves originating from the ears), the overall activity of the brain will respond to and align with these pulses. By selecting the desired rate, the brain via the frequency following response (entrainment) can be naturally induced towards the selected brainwave state.
  There’s an added bonus feature you get with the Brain Evolution System™: scientific studies indicate that brainwave entrainment can not only enhance normal thinking to higher levels, but can also act as a “mood enhancer” to alleviate depression, chronic fatigue, and related conditions – as well as the physical symptoms brought on my too much stress.
As somewhat of a modern mystic, I have studied altered states of consciousness, but due to my monkey mind, I have only been able to experience them to a very minor degree. I have tried so many methods of meditation to little avail. But I became aware that I would not be able to progress in my spiritual life if I could not achieve at least a modicum of success in meditation.

The functional role of neural oscillations is still not fully understood;[6] however they have been shown to correlate with emotional responses, motor control, and a number of cognitive functions including information transfer, perception, and memory.[7][8][9] Specifically, neural oscillations, in particular theta activity, are extensively linked to memory function, and coupling between theta and gamma activity is considered to be vital for memory functions, including episodic memory.[10][11][12]