Well I’m a bit hesitant to answer your question, especially the last part because it is essentially asking me to show you how to get away with cheating. I’m not against PED per se, but I’m against their use in events where they are prohibited.
Can a TRT dose lead to a positive test? Yes it can. Several master athletes have tested positive due to TRT.
Could you get away with it without having to stop prior to a competition? Yes you cpuld because a TRT dose (which can be anywhere between 100mg/week to 200mg/week in most cases of injectable testosterone… the dosage can be even lower if testosterone cream is used in which case a dose of about 20-40g is used but only about 10-20% is bioavailable, leading to an increase of maybe 4-8g per day, which is right around what a normal male produces daily). With a dose that low it is possible to avoid going past the 4:1 ratio.
The WADA tests can now differentiate between natural and synthetic testosterone. This means that in the past if you didn’t exceed the T:E ratio you were fine. But now they can actually decide to test of your T level is from your natural production or exogenous. However this is a separate test and normally they only use it if someone exceeds the T:E ratio, is very close to it (3.8:1 for example) OR if there is a legitimate reason to suspect exogenous T use (for example if a 70 years old master competitor has high normal T).
Some athletes have gotten away with using synthetic testosterone by switching to short esters (or testo cream or oral test, “andriol”) around 6 weeks prior to a competition and stopping 1-2 weeks prior. That couldn’t be done with a steroid that is foreign to the body and for which the slightest level of metabolites could be detected… that’s why a lot of athletes were popped recently: the tests are now A LOT more sensitive and can detect an extremely low level of metabolites… this screwed up the “detection time” that was know by coaches and athletes. But since they don’t test for testo metabolites even if there is still some residual left in the body the athlete MIGHT be okay.
But I will be honest, if one of my client who was a master athlete decided to go on TRT, and if it is medically justified for his health and well-being I would tell him to do the right thing and petition for a medical exemption. And if it is refused I would advise them to either go on TRT and have a better quality of life and NOT compete OR don’t go on TRT, be miserable and compete. I would personally not accept helping someone go against the rules of his federation (the fact that many others don’t follow the rules is not a justification). If the athlete’s demand for medical exemption is refused, going into competition using TRT IS against the rule.