They're not hard. They just had a bit of a wrestling match. They didn't even break the other's skin.
Now, the chinstrap penguins, braving 60 foot waves, against jagged rocks, then walking two miles every other day, just to feed the chicks? That's hard.
Those penguins were amazing. The footage (not this programme) of Emperor penguins in the Antarctic where they change the front rows constantly as they move forward into howling winds at sub-zero temperatures is a sight to behold. Tough little blighters.