It might seem unusual for a breathing supplement to come paired with a heart-health capsule. Here's the physiological reasoning behind it.
Your lungs absorb oxygen from the air into your bloodstream. Your heart then pumps that oxygen-rich blood to the rest of your body. Neither step matters much without the other functioning well.
Improving oxygen absorption in the lungs won't meaningfully help daily stamina if circulatory delivery is under strain elsewhere. The reverse is also true.
A paired system that targets both the respiratory and cardiovascular side at once reflects a more complete view of how oxygen actually reaches your body's tissues.