It's like anything else. When you are running those nerves, receptors, and transmitters on overdrive because of your demanding lifestyle somewhere you are going to suffer wether it be shitty lifts, anxiety, depression, or poor vision. It's not going to be something you notice on a large scale at first but you can't possibly beleive that using a stimulant on a daily basis will go without some consequence. It creates a response in your body to consistantly run on the "fight or flight" response keeping adrenaline and stress hormones in the body. If I were to give you advice I would say keep it to 1-2 cups of coffee and thats it. Everyone is different and will