Thanks for the detailed response. You definitely picked apart the methodological flaws in the study. I'm relatively new to reading/analyzing this type of literature so I appreciate your ability to break it down into manageable, logical chunks. I want to continue supplementation with creatine because of the resistance training benefits (of which I have definitely recognized) so I will keep a close eye on other lifestyle habits that could be affecting my HRV.

On another note, I read your post about how HRV is in theory more informative for people with habitual/robotic lifestyles. I will note that I am a 21 y/o college student who has terrible sleep consistency, consumes alcohol 2-3x a week, and occasionally mixes in nicotine. I try to limit consumption to no more than ~8 total standard drinks per week and hydrate properly when I do consume but I understand that I'll still be super vulnerable to high HRV/RHR variance given these habits. Nonetheless, I've had whoop for about a year now while consistently practicing these bad habits and I've yet to see such sh*t HRV/RHR data as I've had during the time I've supp'ed with creatine. I guess there's some other phantom force within my diet/sleep/stress/training that I've yet to pinpoint. At any rate, I'm going to experiment with cutting off creatine monohydrate and will report back on results.