Husband won’t listen

Apple17

We just found out on Monday that we are going to have to undergo

IVF

and my husband has been told to wear loose underwear and to stop cycling as he has a severely low sperm count.

He says his underwear is breathable material so doesn’t need to change it, and that he’s researched it and cycling doesn’t do much.

He doctors have told us what to do and he’s not listening. I’ve tried to convince him and we just end up arguing. Any advice?