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.
Generally speaking, the brain will usually entrain to the strongest stimulus which would be isochronic tones over binaural beats. So when you see people add binaural beats at a different frequency to the isochronic tones, that would not produce additional brainwave entrainment at another frequency. If they are both at the same frequency I haven’t seen any research to indicate whether that would be beneficial or not, but my belief is that it would weaken the potential for entrainment. When you look at the waveform of an isochronic tone there is a distinct empty space between each beat, making it very pronounced and effective. When you add binaural beats at the same frequency it looks like this: http://www.mindamend.com/wp-content/uploads/2017/11/isochronic-tones-binaural-beats-combined-waveform.jpg. The depth of the waveform is now half as deep and less effective. This is before the binaural beats are formed inside your head, where the waveform is hard to determine and measure. From listening to that type of combination the beats sound much less pronounced, which has to make them much less effective in terms of a brainwave entrainment stimulus, compared to isochronic tones on their own.
Our everyday, waking brain used for active intelligence operates at approximately 13 hertz, which is in the range of high alpha or low beta frequencies. People who have certain learning disabilities and problems with attention often have low levels of 13 hertz frequency brainwaves in crucial areas of the brain used for sequencing tasks and doing simple math calculations. This is one concrete example of how brainwaves are associated with thinking and behavior. Each identified brainwave frequency has a different effect on a person’s ability to think, act, and feel.
I’ll give you another relevant analogy. When you are bodybuilding, working hard to build strength and build your muscles, you can push yourself to the point that we know is healthy. But what happens if you try to max out with the same exercise past the point that we know your body can handle? You’re going to get hurt, and you’re not going to get buff any faster. You can’t just push yourself to the limit with the barbell as many times as you want in a day/week.
If brainwave entrainment leaves you with unwanted side-effects (see below) or discomfort, you’re probably encouraging a range of brainwaves that are already excessive in some area of your brain. The way around this is to get a brain map to see what your brain’s strengths and weaknesses are, and see what (if any) brainwaves could use some encouragement.