From https://www.ncbi.nlm.nih.gov/pubmed/22030953
Andrew P. Wroblewski, Francesca Amati, Mark A. Smiley, Bret Goodpaster & Vonda Wright (2011) Chronic Exercise Preserves Lean Muscle Mass in Masters Athletes, The Physician and Sportsmedicine, 39:3, 172-178, DOI: 10.3810/psm.2011.09.1933
It weaves in his "6 Rules of Success" into a very inspiring video... not just for Gym motivation, but for any kind of goal you are trying to achieve, but aren't making progress towards....
Related: Arnold Schwarzenegger - "Who do YOU want to be in life?" https://www.youtube.com/watch?v=vH0nP4NzS9M
For me, it depends on the day: Ronnie squat (https://www.youtube.com/watch?v=LVVdlwf1iyM)
Eddie Hall Deadlift (https://www.youtube.com/watch?v=U4AQlamvFzs)
If lacking the motivation to DO usually Kay Greene works: https://www.youtube.com/watch?v=-jVQnoQ1S6U
Something more fitness-y , like Steve cook: https://www.youtube.com/watch?v=tNsc5GIUPIY
And if I want something more different, I check the last video from NickVisionMotivation, awesome videos!
(Go Big Ramy or Nathan for Mr.O for anyone following the scene!)
And a non Kai classic: "There is no reason to be alive if you can't do deadlift." https://www.youtube.com/watch?v=ZWUcHKAj_tc
Of course there is always watching Arnold pose to get you motivated.
I really like this topic.
OR something by nickvision motivation or makaveli motivation.
This ones the best I've seen (and I'm not a huge Dorian fan):
I also find that I row the fastest during commercials, so Netflix/Amazon Prime shows are actually worse for me when working out.