I know coffee is an excellent beverage. I didn't use any sugar or milk either. I still love the smell when my family members brew it. I thought I was addicted to it but nowadays my body does not crave it anymore. We all tolerate caffeine differently. I don't ask my readers to give up coffee. I only point out that excessive caffeine especially on empty stomach with excessive workouts might raise cortisol hormone. You may check with your healthcare professional. Cortisol tests are cheap and available in many countries.