The back-story here is that I'm a 36 y/o, female, and I have been strength training at the gym for the last 4 years. I'm the strongest I have ever been and yet feeling stagnant over the last 6 months or so. My fiancé and I usually go to the gym after our long work days and I am usually pretty mentally fatigued by 3 PM. I am pretty sensitive to caffeine in the afternoon, but thought I would give this a try. Honestly, I notice a difference within 10-15 minutes of drinking and have enough energy for my entire workout. My attitude is better. I'm more motivated to push through and work harder. It tastes great...the slightest chalky taste, but nothing the flavors don't make up for!
The best part for me is that the caffeine doesn't seem to be making it difficult for me in the evening time. I have found that any caffeine in the afternoon usually means late nights of tossing and turning rather than sleeping soundly. So far, I haven't had that issue here. It's been great!