You do a lot of small changes (<100 loc) that get reviewed often. If it doesn't get reviewed often then the whole idea of continuous development breaks down.

Argueable you have 8 hours of work a day. How many of them do you need to write 100 loc? After that 100 loc or maybe 200 take a break and review other people's code.

Plus you also have random meetings and stuff so your day already fragments itself so adding a code review in the time before a meeting or after is "free" from a fragmentation standpoint.