Fiber internet bottlenecked by Ethernet cable?

On Thursday I am upgrading to fiber Internet! But my house has had the same Ethernet cables running through the house for probably around the past 5 years. What is the probability that our 1k Mbit internet will be bottlenecked by the old Ethernet? Not sure what kind of cabling it is but I'd assume it's not that up to date, but it treated out 40 down 15 up just fine