Up until recently I have been out of the game all together for about 3 years, damn you drugs and alcohol, but made a decision to get back to what I love. I remember some years back, pre workouts would warn of not using on consecutive days or no more than "x" amount of days per week. I thought then it was because of potential cardiac problems but then I began learning of neural fatigue. Now I am familiar with the body's ability to build a tolerance for certain substances (I experienced this myself with the aforementioned plagues in my life.) Does this still hold true with today's pre workouts, should it be used sparingly, cycled or has the supplement industry come so far as to make them okay for everyday use? I don't even use the recommended serving.