This normally wouldn't be applicable to profiles by our standards, but I'll answer this the best I can anyway.
Well, sources both educational and governmental vary on how dense a white dwarf star is. NASA says a white dwarf's density is 10^9 kg/m³:
https://imagine.gsfc.nasa.gov/science/objects/dwarfs2.html
Ohio State University puts the density of a white dwarf anywhere from 10^5 to 10^8 g/cm³ (10^8 to 10^11 kg/m³):
https://www.astronomy.ohio-state.edu/johnson.3064/Ast162/lectures/notesWL22.html
And this document from the Lulea University of Technology puts the upper limit of the density of a white dwarf star at 10^7 g/cm³ (10^10 kg/m³)
Assuming a density of roughly 1000 kg/m³ and a weight of 62 kg for a human, we'd have a volume of 0.062 m³ for a human.
Using the range covered by Ohio State University gives us a range to work with as white dwarf star density is basically speculative. Going off this, we have a mass of 6200000 to 6200000000 kg.
An amateur boxer is believed to punch with a force of 2500 newtons:
https://boxingscience.co.uk/science-behind-punch/
The weight of an average person, by comparison, would be 608.0123 newtons. This should give a rough approximation for the punching force of around 4.112x a person's weight.
Based on these figures, a person as dense as a white dwarf star should have a punching force of 2.5*10^8 to 2.5*10^11 newtons.
Punches are typically measured over a distance of a foot, as we would learn from how Rocky Marciano's punch is measured (pound-feet). Going off this, here's how much energy is put into a punch of someone like this.:
2.5*10^8*.3048=76200000 joules
2.5*10^11*.3048=7.62*10^10 joules
That's 7.62*10^7 to 7.62*10^10 joules, or 0.0182122371 to 18.21223709 tons of TNT. That's a range from
Small Building level to
City Block level.