I insist on?How long can you hold?

I insist on?How long can you hold?
I insist on?How long can you hold?

I insist on?How long can you hold?
前面那句,我的翻译是“我还要坚持吗?”,不过感觉有点怪,因为insist作为不及物动词意为坚持,坚决认为;强调；坚决主张;一定要[(+on/upon)].例如：He insisted on/upon my going with him.他坚持要我跟他一起去.I insist on seeing it.我一定要见到它.
后面那句是“你可以支持多久?”