Mike Gérard Tyson became the World youngest boxing heavyweight champion at age 20 because of these:
Check the picture.
Yes he did all that daily from day one till he retired in 2005.
This was huge. Call it herculean task you won't be wrong.
This made him win most of his professional fights with knockouts in round one. He was indeed a delight to watch.
He trained very hard.
He was consistent.
He was persistent.
He was determined.

Sincerely can you try any of these? Or do you think any of today's boxers still train up to this level.
Has heavyweight boxing standard dropped?

Iron Mike Tyson.... The Phenomenon

Sheguama:

Iron Mike Tyson.... The Phenomenon

Indeed