Does TRT actually improve your cardio performance and VO2 max?

Testosterone influences erythropoiesis (red blood cell production), which can modestly enhance oxygen-carrying capacity, though direct improvements in VO2 max are often secondary to body composition changes and better recovery rather than a direct endurance boost. While some men report feeling less winded during aerobic work, excessive doses can actually impair endurance by raising hematocrit and blood viscosity too high. At HeydayMD, our clinicians closely track your CBC labs and cardiovascular biomarkers to ensure your protocol optimizes your physical performance safely.