build up

As the energy builds up, two electrons are separated from the chlorophyll and move on to prepare for the next act.

This stag has built up a harem of females.

This gives your gut time to build up a strong community of beneficial bacteria to outnumber and outcompete any illness-causing germs.

He said: “The tendency to press a button may be building up for 500 milliseconds, but the conscious mind retains the right to veto any action at the last moment.”

We can also use erupt in an emotional context to talk about a sudden and intense release of a feeling that's been building up, much like the pressure of a volcano.

Unfortunately for the Bald Eagle, the same folks who bestowed upon it this newfound honor of national bird would soon spread across the country, building up massive cities and populating areas that were once wilderness.

It's something you have to give yourself permission to take a little bit of time to practice because you're building up neural pathways associated with a certain behavior, and those neural pathways just build up over time.