3 ms·

What is it then?

• taeric 3y ago
  I don't know. Haven't read up on it.
• zten 3y ago
  Your heart literally gets bigger! Your stroke volume goes up, and you probably have more blood plasma, too. This aids in fueling muscles. Though, if you Google heart hypertrophy, you'll find a bunch of scary things, because your heart can also get bigger in a bad way rather than a good way.
  • taeric 3y ago
    I'd guess there is also some efficiency in muscle tissue taking in oxygen over fat tissue? Also a bit better lungs, for runners and such? Though, I also don't know the relationship between lung efficiency and heart rate. If you have links on any of this, it feels like it would be a very fascinating read.