I ask you now, what am I, with these clues I have amassed?

Question

You would do well to save me, lest your pearls 'fore swine be cast.

If you wish to catch me, you needn't run too fast.

If you try to hold me, when we're done you, will be gassed.

But go without me too long, and I will have been your last.

What am I?

Answer 1

I believe it's

your breath.

You would do well to save me, lest your pearls 'fore swine be cast.

Save your breath, to not waste words on unappreciative people.

If you wish to catch me, you needn't run too fast.

You can't catch your breath if you're running.

If you try to hold me, when we're done you, will be gassed.

After holding your breath, you would be faint.

But go without me too long, and I will have been your last

People tend to die if they don't breathe.