[Grammar] I have got confused "none more so than..."

[blackdragon]

I, by chance, found an interesting article,

in which was written "Olympic athletes have to go through many trials and work so hard to get to the Games, but none more so than Lopez Lomong, who is representing the United States in the 5,000m race...." (BBCLEARNINGENGLISH.COM)

.
The meaning is quite easily caught up, but i don't do know why the writer used "none more so than"; he or she could write "none harder than Lopez Lomong" instead.
Please help me make it clear.. thank you all!

 

[Rover_KE]

'...none harder than' would only refer back to 'work so hard'.

'...none more so' refers back to both 'go through many trials' and work so hard'.

Rover