Playing Luke Skywalker on screen isn't a piece of cake, and Mark Hamill revealed just how hard he worked to portray Luke's growth. The Empire Strikes Back is famous for many things, including the intense duels between Darth Vader and Luke Skywalker.
Hamill revealed what went into creating these duels in an interview with the BBC a few years ago:
"The Empire Strikes Back, it's such a physical ordeal for my character, and I eventually, as we saw in the little film clip, confront the dark lord. And I have to look like an expert swordsman, which I'm not. So, for four and a half months before we started filming, I started five days a week with karate, kendo, which is Japanese swordplay, I did some weightlifting, and I took fencing."- Mark Hamill
Hamill's training was intense because he performed all his stunts alone, without anybody double. The hard work paid off because, although the duels in the original trilogy aren't as appreciated as the prequels, The Empire Strikes Back's father-and-son duel might be among the top 3 best Star Wars duels of all time. The emotional weight the duels between Luke and Vader carry is up there with Anakin Skywalker and Obi-Wan's duel on Mustafar.
While Luke trained hard under Yoda on Dagobah, Mark Hamill had to sweat buckets to achieve the fitness required for the movie and to film these scenes for the movie. He discusses what it was like filming the first The Empire Strikes Back duel with Vader and the physical toll it took on him:
"They had to keep mopping me down because, as I would do the physicality of the fight choreography, I would sweat buckets. Once the choreography became second nature to me, it felt really good. Also, it was a great way to lose weight. You can eat anything you want, and you lose many pounds per week. It’s difficult but satisfying."- Mark Hamill
The result of their first confrontation is similar to Anakin's defeat at the hands of Obi-Wan in Episode 3: Revenge of the Sith, as Luke loses his hand. The loss of his hand serves as a reminder to Luke of what he's up against and that besting his father physically wasn't the way to defeat the dark side. Instead of physical strength, Luke had to work on his mental strength to appeal to his father's emotions. That meant a stronger connection to the Force and faith in whatever good he believed still existed within Vader.
Ultimately, Luke defeats Emperor Palpatine and Vader through his belief that there's still some good left in his father, which shows that his reliance on his physical abilities took a backseat. But Hamill's intense training paid off and made his duels against Vader look visually incredible and some of the most well-choreographed ones in the franchise.
Even though Luke never became the best duelist in the galaxy, his strength lay in his connection to the Force. Because of this, he brought his father back from the dark side and saved the galaxy from complete destruction.