Done every morning at the end of his morning routine.
Chris said he finishes his morning routine every day with Stu McGill's Big 3 core-stability exercises and has been strict about it.
“So, that's every single morning. I've been very, very religious with that.”Chris Williamson
Source: Morning Fitness, Optimizing Hydration, Screentime Management, Sleep Tips, Cognitive Biases & Other Uber-Helpful Life Hacks With Modern Wisdom's Chris Williamson (Ben Greenfield Life transcript) (podcast, 5 May 2022)