The energy and focus I felt from 1 scoop of C4 was a pleasant amount. Not too strong, but definietly enough to feel the difference. If I was feeling particularly tired one day, I could manage a second scoop and still not feel uncomfortable from too much caffeine. BeachBody On Demand It provided a nice clean, non-jittery feeling of focus too. In terms of endurance, I felt that C4 did a pretty good job of getting me ... Read more