Stew Smith (https://www.stewsmithfitness.com) and Jeff Nichols (https://www.performancefirstus.com) discuss the new testosterone to epitestosterone ratio (T/E) used at BUDS to deter use of performance enhancing drugs.  I hope it works in that reasoning but it also catches non-PED users in some situations. 

BOTTOM LINE - DO NOT USE THEM - you do not need them.  But if your T/e ratios are naturally high - here are ways to reduce them (think of the worst training advice you can ever give someone)...(see below)

Here is what a drug testing program should look like - https://ncaaorg.s3.amazonaws.com/ssi/substance/2021-22/2021-22SSI_DrugTestingProgram.pdf

Need to reduce your testosterone naturally?  See https://www.medicalnewstoday.com/articles/325186

Sleep reduction = testosterone reduction - https://jamanetwork.com/journals/jama/fullarticle/1029127

Check out other videos of combat swimmer stroke, workouts, and other spec ops related training.  See http://www.stewsmithfitness.com for more information about military, law enforcement, special ops, fire fighting training programs.