I'm on the estrodot patch, and work out until I'm as wet as i am in the shower...... it has never fallen off. I am also a firefighter, so I work hard, and it has never fallen off. I use two a week. One for three days, one for four. There are 8 in the box.
Also, transdermal estrogen has been shown to be less of a clot risk than pills. Which was a benefit for me.
My endo is fantastic. His approach is simple... stop the testosterone, and your body won't need high levels of estrogen. I'm on Lupron Depot, which is expensive as hell... (I get it from Canada for much less than the US). Had great results, even at 42 years old. I read a lot about HRT before starting, and never saw anything about Lupron. Of course, there's also the orchi surgery... that will also stop your test, which will lower your need for the amount of estrogen.
Health wise, it's a great option. Stop the testosterone, lowers the amount of estrogen to cause feminization. Makes sense.
But back to the patch... never had a problem, and I am very, very active.