With how massively parallel the human body is, this process is copying DNA at an average rate of around 1 million miles per hour if you put all the DNA into a single string. (Consider that each human cell contains about 2 metres worth of DNA)
https://en.wikipedia.org/wiki/Helicase
The wild thing is that it doesn't have a 'gas tank' of ATP to drive the reaction, it goes this fast while being fueled one molecule at a time from the environment.
Where does the ATP come from?
Buckle up my mechanical engineer friend - https://www.youtube.com/watch?v=OT5AXGS1aL8
I've watched that video a hundred times and it still gives me chills haha.
Also you may be interested in flagellar motors: https://www.youtube.com/watch?v=VPSm9gJkPxU
For example, see Table 1: https://book.bionumbers.org/how-quickly-do-different-cells-i...
You /could/ compute a global mean or median mitosis rate, and show how it changes/doesn't change with age, but it wouldn't say very much biologically. A narrower analysis that considers cell type and other context could be meaningful.