epo

Just found this and thought it was interesting - maybe drinking lots of black tea for its theophylline content could help reduce hct levels? https://www.nejm.org/doi/full/10.1056/NEJM199007123230203

Why do some guys report getting out of breath easier when their HCT is high, yet athletes use EPO to increase their RBC’s, which would obv increase their HCT as well. Why are these athletes getting improved cardio, while guys on TRT report decreased cardio when their HCT levels get too high?