Caffeine is awesome. However, it's one of the most powerful (legal) supplements in existence and we have to be careful not to over do it.
The American Heart Association recommends no more than 400mg of caffein per day. Some people are definitely more sensitive to it than others, and regular caffeine consumers will build up a tolerance just like with any drug (yes it is a drug!).
From a performance perspective, one of the coolest things about caffeine is that it has been shown to enhance both power and endurance sports.
Strength benefits include stronger muscle contractions.
Endurance benefits include increased time to exhaustion, lower rate of perceived exertion and increased glycogen sparing.
Of course we've all noticed the enhanced alertness, focus and reaction time.
Athletes across the board regularly use caffeine supplementation before training and events to enhance performance, but in addition to the long-term health concerns of chronic or excessive dosages, you also have to be wary of possible immediate negative effects if you're sensitive to caffeine. These possible effects include anxiety or the jitters, sleep problems, gastric distress, etc.
I personally like to use caffeine on an as needed basis so that i don't build up a tolerance to it and lose the benefits. If I'm really tired or going into an important competition then I'll probably give it a go, or if I'm just trying to enjoy a nice cup of joe - I love coffee. However, I try to avoid drinking it on the weekends or everyday.
As an alternative to coffee, I sometimes drink green tea, herbal teas or hot bone broth to get that same good feeling and some other health benefits of those alternative substances without intaking so much caffeine.
In summary, coffee and caffeine is dope - we love it, but approach it intelligently, and let us know if you have questions about caffeine or any other supplements or nutrition related questions!