What actually happens with your body if you increase cardio?

Question

For example you could be super in shape from a muscular perspective but have really bad cardio and vice versa.

How is cardio different from physical shape and what exactly happens in your body that makes you have more cardio?

In: 368

Answer 1

Your heart is a muscle just like your biceps and it’s needs a workout to get bigger just like those curls for your biceps.

When you exercise your muscles need extra oxygen to burn energy and so your heart needs to pump faster to get that oxygen to your muscles. Only problem is the fact that the heart needs to fill up with blood in between each beat to be able to pump effectively, and so if it beats to fast it will reach a ceiling where pumping any faster will start to become less effective at pumping (above 160bm roughly). If someone is exercising so hard that they need more oxygen then the heart can provide to them when pumping at 160bpm then they are in trouble. To combat this, we can train our heart by doing cardio (cardiopulmonary exercise) which results in making the heart muscle grow bigger and stronger (just like bicep curls give u big biceps like popeye). By making the heart 2x stronger, the heart can beat at 80bpm and can pump the same amount of blood it used to pump at 160, and therefore it can pump even more blood when it reaches the max HR of 160, increasing someone’s overall exercise tolerance+endurance+capacity.

Now unlike your biceps, you can’t consciously control your heart to work it out by doing 10 reps of heavy pumping, so instead you get it to do sustained fast pumping which works similar to doing low weight high rep curls at the gym. So you do anything that causes your heart rate to go up (above 100) and you sustain it at that level for a extended period of time (5+ minutes). Common forms of cardio include running cycling or swimming. This is why getting jacked at the gym by doing heaps of heavy lifting won’t necessarily result in having a good strong heart, because the heavy lifting doesn’t cause sustained high heart rate, it’s just raises it during the set (1-10 reps=5-30 seconds) as opposed to 10 minutes of running on a treadmill which might not lead to big muscles on the outside but will help build a big strong heart muscle on the inside.