What determines your vascularity, is it mainly genetics?

[PeatandPotatoes]

I was wondering what determines your vascularity, is it mainly genetics?

I am around 10 % body fat (maybe a little less) yet my veins only ”show” when I am hot or working out
when I work out or hot I have veins in my abdomen, arms, shoulder, and chest showing, but when I am cold or not hpot you can barely even see color of veins in my arm

 

[aliml]

Blood flow restriction training (BFRT) increases vascularity

Veiny Arms: What Causes Them and How to Make Your Veins Bulge

Veiny arms aren't a complete marker of fitness since they can occur naturally. Some people are extremely fit but don’t have pronounced veins, and others are naturally vascular even if they don’t spend time in the gym. Learn what causes veins to pop and what you can do to make your veins more...

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