[perilunar]

> Black tea is a good aid for sustaining my focus. It improves focus, but doesn't create the same stress on my body.

Black tea contains 30–90 mg of caffeine per cup (and some theobromine and theophylline, which are similar to caffeine, and also stimulants.) Giving up coffee because of the caffeine but dinking black tea instead is self-defeating.

[bayindirh]

I'm aware, but as some studies [0], and my body, shows, their effects are not similar. Black tea doesn't make me tense and causes heart palpitations for me. Instead, I keep my calm and being able to focus.

I don't reduce coffee because of caffeine, but because it affects my appetite, makes me tense when I drink too much, and causes heart palpitations and makes me uncomfortable. Black tea doesn't do any of that.

[0]: http://apjcn.nhri.org.tw/server/apjcn/17/s1/167.pdf