Great thread. Been on blood thinners for about 10 years off and on, I'm a lifer since my second massive DVT.
During the first go-round, my doctor banned me from everything. Then, her brother died, and she changed her thinking, just told me to be more careful-- no skiing on weekends or at night, no big waves on the body board. On the bike, I avoid sustained risk-- I'll still go north of 35 MPH if conditions are right and I'm feeling sharp-- but only briefly. I'll ride intermediate/advanced trails, but I'm not going that fast-- like, zero loss of traction allowed, no skidding, no wheel locking.
I still skied double blacks locally and single blacks on larger mountains until I stopped in 2019. My doctor even signed off on two scuba dives in 2017 limited to... was it 30 feet or 40? I can't remember now.
Obviously, nothing I'm saying should be construed as medical advice, but I prefer Warfarin to the modern blood thinners because it's more easily reversible and because your INR gets checked regularly. Hard to believe that Xaltero, Praxada and Eliquis really do not need monitoring-- one dose fits all? How could that possibly be? It seems like my friends on newer blood thinners bruise more easily than I do, but that's obviously purely anecdotal.
Okay, here are some warfarin sports stories for your general amusement:
One of my most amusing situations was skiing Mammoth with one of my buddies in 2017-- he knows I get terrible migraines, and after skiing Cornice three times and Scotty's once-- and I was not going slow either-- he asked me how I was doing. I said fine, except for hallucinating an enormous green blob in the center of my field of vision. He suggested we descend 1,500 or so and ski at lower altitude, which was fine for two runs, then he asks me, "How's the green blob?" I'm like, "Mmm, I'd have to say it's bigger. Greener." He says, "We're going down-- right now-- and slowly. I'll follow you."
The migraine came shortly after that. Two Norco didn't touch it. Neither did two more four hours later. After eight hours and six Norco, we decide I should go to the ER. They get me set up with 02 and MORE narcotics, give me a brain scan, everything checks out, I'm feeling much better...
Feeling really guilty, I tell them I cut back-- just slightly-- on my Warfarin to keep my INR barely on the edge of therapeutic-- it's supposed to be between 2 and 3, and I get tested before anything too extreme, so I know how to shave it right to 2.0.
They said, "Yeah, you really shouldn't do that. However, you're like the sixth guy we've treated this season who made that confession. They all lived. Just don't skip it completely."
A guy T-boned me once in the CRX-- total doofus move, I slammed my head against the window, it was bleeding when I got out of the car. He was such a dork I wanted to slug him-- so, remembering the AA principle of contrary action, I HUGGED him instead: "I'm so glad neither of us got killed!" That bled a bit, got a brain scan, I was fine.
My little terrier woke up having a seizure and bit me in the face-- THAT scared me, bled like CRAZY, I thought, "Crap, I actually could bleed out before the ambulance arrives." The dog is in a post-ictal freak out, like, "What did I do?! I'm the worst dog ever! Give me the needle, send me back to the pound, I deserve it!" By the time I pick up the phone, I'm realizing, "Huh. Maybe I can drive to the ER." Which I did.
I really wouldn't want to dive at all, ski anything harder than a small mountain single black, or body board waves bigger than 2 feet with an INR of 2.9. If I'm pushing it, I'll pay for an extra test, and try to go when I'm in the low 2s. eMTB, I don't worry that much. Never fell much on a regular bike, never fell at all in the last 30 years or so, and I plan on keeping it that way.