What’s a little superhero/ninja training on a Friday night.

Arrow star Stephen Amell demonstrated the salmon ladder exercise with his friend Ankur on social media. As Ankur learned, the exercise is far more difficult than it appears.

The exercise has been a staple on the hit CW series since its premiere. Amell’s Oliver Queen is frequently shown performing the difficult exercise as part of his workout regimen. This season fellow superhero Ray Palmer (Brandon Routh) was caught by Felicity performing the exercise in his office.

The salmon ladder has also been prominently featured on physical competition shows such as American Ninja Warrior.

Arrow takes aim on Wednesday nights at 8/7 c on the CW.