That all said, we are all different and have our own different limits. So I generally advise that you just be aware of how you are feeling, and if you feel like you are getting a bit fatigued from it, it’s probably time to stop or at least take a break. When listening over long extended periods, I recommend that you keep yourself well-hydrated. Your brain needs a good supply of water to function well, especially if you are studying hard and increasing your brainwave electrical activity.
Entrainment guides our brainwaves into targeted ranges, but they are ranges we go through naturally many times every day. LifeFlow 10, for example, takes the brain to a 10Hz frequency. We experience this same frequency when closing our eyes and taking a deep breath, or when consciously relaxing physical tension in the body, or when we find ourselves lost in a daydream, or when we view a beautiful sunset, or when we find ourselves caught up in an especially peaceful bit of music. If there was a cause-and-effect relationship between these 10Hz brainwaves and our face flushing, then our face should also flush when we enter that daydream, listen to that piece of music, watch that sunset, or close our eyes and relax. The same brainwave patterns are present during all those activities as they are while listening to LF-10. But these other activities don’t bring on the same face flushing.
For a little variety, you can use the 60 minute Delta Ultra Deep Standalone Meditation which takes you down into Delta and holds you there for an extended period of time. If you can stay awake during this entire time, you will have some amazing meditative experiences. (If you fall asleep, don't worry! It's natural and with practice you will be able to stay awake more often.)
Another common misconception is that entrainment is going to force your brain into doing something beyond its native capabilities, or at least beyond what it is accustomed to doing. This mistaken belief is often the root that leads to comments like, “When I meditate with LifeFlow my face gets flushed (or my hair vibrates or I develop x-ray vision, or any of the other things we come across). If I meditate without LifeFlow the face flushing doesn’t happen. LifeFlow must be causing it.”
There are various reasons we seek this sort of validation. Many of us first try meditation to find relief from all sorts of different problems. Some seek relief from physical or emotional ailments; for solutions to personality shortcomings, such as a short temper or a tendency towards jealousy, etc. Some problems may be quite serious, even life threatening. Our search for relief may have been going on for a very long time without having found exactly what we were searching for.