The first eligibility requirements on the 2016 application website says:
Does a person on H-1B or L1 work visa qualify as legal resident?
"Resident" of US is defined differently for immigration and tax purposes. Work visa holders are considered non-resident as per USCIS, but considered as residents by IRS for tax purposes. Which one applies here?
Also, does anyone know a contact email or phone number where I can contact American Ninja Warrior for clarification?