Why cant we do this all the time

You know how when your adrenaline is going you become stronger? Why cant we harness the power to do this whenever we want?

Adrenaline is secreted into the blood stream all the time as it helps REGULATE body functions and at times you surprise yourself by your strength and speed, that's adrenaline rush too. But its only in extreme cases, like a fight, that you notice really considerable boosts because your brain has triggered more adrenaline to be secreted.
I don't know if you can control adrenaline secretion because it's an involuntary process but you can't keep it going because the results, like mental awareness and super strength, when prolonged lead to headaches, muscle cramps and much more.

Well the adrenaline rush is when the blood rushes, so it does it automatically, and you can't just make your blood rush

you could if you could spike your blood sugar and blood levels constantly but unfortunately we dont really have control of that...except for diet of course