A thread on how your body type & genetics can influence cardiovascular training adaptations

We’ve all noticed that some excel at sprinting and others long distance running. But it gets deeper

Our skeletal structures influence our ability to utilize & deliver oxygen. There are..

two main types. Let’s start with endomorphs, or wider individuals who have a frame that allows them to put on muscle.

They usually excel anaerobically & have great local muscular endurance, but if you were to put them in a metcon or circuit-style training session, they wouldn't

last very long because they struggle to deliver oxygen to working tissues in a global manner.⁣

They tend to have muscle stiffness which allows them to produce force rapidly, but at the cost of wanting to cut off (occlude) bloodflow from passive tissues to working muscles.

For more information on occlusion, see this thread: https://twitter.com/conor_harris_/status/1279883605922115585

The other end of the spectrum is an ectomorph. These individuals are your more narrow-framed people who can't as easily put on muscle mass, but excel aerobically.

They have a great ability to deliver oxygen because they don't occlude/compress their veins and arteries as quickly.

We know that the best athletes are the ones that can contract (produce force), but also relax their muscles as quickly as possible to allow for blood to resaturate the tissues with oxygen.

So endomorphs are better at the former and ectomorphs the latter.⁣

Endos need more light work that doesn't force them to occlude. Circuits of bodyweight squats, light dumbbell work, etc, as well as short duration intervals of sub-max intensity are going to be better for them because they won't cut off blood flow quickly and also leave time

during rest to deliver oxygen and relax (their weakness).⁣

Ectos need more focus on higher relative intensities at either short durations (i.e. Tabata protocol) and/or more moderate-to-long intervals to train the ability to utilize oxygen better.

I would like to add that this is a working theory that holds up well to a lot of what we understand.

This specific idea hasn’t been studied in great detail as far as I’m aware, but there is a lot of supporting data through tools such as Moxy monitors.