Park Bo Gum shocked fans when he admitted his Good Boy training was "very hard both technically and physically" – and after hearing what the cast went through behind the scenes, we totally understand why! The current #4 global hit on Amazon Prime didn’t come easy, and these 12 challenges the actors faced will blow your mind.
From Tae Won Seok gaining a jaw-dropping 20 kilograms for his discus thrower role to Kim So Hyun holding weapons for 40 minutes straight, the dedication was unreal. Park Bo Gum spent 6 months doing 3 hours of daily training – 1 hour strength work plus 2 hours of boxing practice – just to nail his first major action role. Meanwhile, Heo Sung Tae revealed he filmed during the most difficult period of his life, using all his creative energy and ad-libs to cope.
The most intense part? Kim So Hyun had to overcome her genuine fear of weapons, describing the experience as "quite scary" but admitting it made her stronger. Lee Sang Yi underwent 6 months of fencing training with zero experience, while Oh Jung Se dove deep into his childhood trauma to create his "ordinary-faced monster" villain.
But here’s what makes it even more incredible – despite all this suffering, the cast couldn’t stop laughing on set! Park Bo Gum was apparently the first to burst out laughing during takes, with the entire set constantly filled with laughter. The chemistry was so good that time flew by without anyone noticing.
Now that Good Boy is dominating charts worldwide and proving Park Bo Gum can do action just as well as romance, all that blood, sweat, and 20kg weight gain was definitely worth it!
