I think more than anything you need to simply KNOW what you're putting into your body with supps. We live in the age of information, you can research anything at the tip of your fingers, and the amount of people cranking down on creatine and pwo with insane amounts of caffeine is nuts.
I love pwo's, but I'm extremely picky about them- you'd be surprised how few are niacin free, or have an insufficient amount of beta-alanine or citrulline, both of which I love in a pwo.
I've always had phenomenal results with simply going hard AF in the weight room and an extremely strict diet with a mix of significant amounts of cardio. I don't get what the point of supplements is when you have a good diet that provides everything your body needs to grow and repair itself.
I do industrial electricity at the refineries and put in just as much OT with labor intensive work throughout the day high amounts of sun exposure. The only thing I changed with my workout/supplementation/diet&nutrition was to start the use or SARMS (selective androgen receptor modulators) but didn't use them for long. PWO is something I absolutely never ever take. If I do, it has to be a non stimulant. I only once bought PWO (non stimulant) and never again. I think it's possible, just gotta want it really bad and be mentally strong or strong willed.
One should do a full scale blood test with their GP before determining if they should NOT take a given supplement. Don't rely on youtube for this.
The video in OP is true in that the medical fields and journals are more focused on sensitivity as opposed to specificity. More on that here https://en.wikipedia.org/wiki/Sensitivity_and_specificity This is primarily for liability reasons, better to get a false positive than a false negative. The rest of it i will not endorse at all.
Basically, under current models, 4 possibilities exist: you have a "condition" and we successfully identified it; you have a condition and we failed to identify it; you do not have a condition yet we misdiagnosed you as having one; you do not have a condition and we determined you dont have it too. Only empirical measurements can identify this, and never at a rate of 100% sensitivity AND specificty. Its always more like 80% vs 95%, or 75% vs 99%.
Sensitivity means exactly as it's implied: the degree to which it detects something. Specificity being the opposite, the degree to which it excludes something. In a perfect world, you hit 100% on both ends (this never happens in science).
The point: Never ever do a medical procedure (or supplement) with a mere two tests. Two is the minimum standard. Do a 3rd or 4th. This minimizes harm on your end. Id rather be 1% wrong than 7% wrong, especially since insurance companies are terrified of false negatives from a legal perspective (meaning they will always cover tests no matter what).
Relying on your own subjective measurements is a mere start. If you are symptom free, fine, do life, but the absence of symptoms, statistically speaking, means literally nothing. Likewise, the presence of symptoms also means nothing if it's only measured a couple times. Everyone likes to convince themselves they are some sort of fucking physiologist (with their lol-degree), yet fail to understand the actual numbers behind how measurements of a deficiency actually works mathematically. Nothing in medicine is exact, even in 2018. Maybe in 3018 it will be 99% accurate but i doubt it.
I think will power and drive trumps all. I've worked 84 hours a week on and off since I was 18 so a good 20 years ago. It's all about routine, when I was working 2 weeks on 1 week off I would hit the gym after work ever day but keep it an hour or under. The week I was home was the problem lol. Also when you get older priorities change if possible get some gym equipment in the house but I know that's tough and expensive. Supplements especially the pw stuff all come in powder from China. I know a guy that manufactures that stuff for several companies.