A note about the aerobic development work on Tuesdays:
Short version: DON’T GO HARD. PLEASE SLOW THE CRAP DOWN. SUSTAINABLE EFFORT, NOT SELF DESTRUCTION.
There are two ways to improve your “cardio” – either by improving cardiac power or cardiac output.
Cardiac power is the force the heart produces each time it beats. More force = the faster oxygen rich blood enters the system and and faster oxygen depleted blood exists the system. This is developed by high intensity WODs, and the gross Assault Bike/Row/Skierg/Sled push stuff.
Cardiac output is the amount of blood the heart “produces” each time it beats. More oxygen rich blood per stroke = more oxygen to produce energy. Tuesday’s aerobic development work, active rest days, and workouts labeled “70-80% Intensity” are designed to improve cardiac output.
In order to increase the amount of blood the heart outputs, we need the left ventricle to grow. The left ventricle only grows when it is fully filled with blood.
Here’s the catch: If you go too fast, the left ventricle won’t completely fill with blood because your body NEEDS BLOOD ASAP, and so it shuttles it out of the heart before the ventricle fills completely. If this happens, we’re developing cardiac power and not output.
This means we miss out on HALF OF THE PUZZLE when it comes to developing your “cardio”. HALF, DUDE. Imagine if your cardio was twice as good as it is right now, because you had the discipline to slow down. CRAZY.
Tips: Keep heart rate around 80%. Take your pulse for six seconds and add a zero to get a ballpark. Think “If the WOD was 15 minutes longer, could I hold this pace?” If so, continue. If not, slow down.
Go slow when you should go slow. Go fast when you should go fast.