Canmore-Jasper leg response.
I don't really consider this an injury, but logging it as such is probably the easiest way for me to find it again to track such things.
I felt my legs responded to the ride very well. The muscles never really hurt, though by the end of day 3 they did indicate that they had been used. But in the last 20+ years, strength hasn't really been the issue, though other things may be constraining leg strength - more on that later.
The issue has been blood flow. I wore prescription compression on both legs throughout. These are fitted 5-10mm smaller than the circumference of my leg. They make riding more than recreationally for short distance possible.
They do not, however, result in blood flow that is completely normal. At about 3 hours into a ride, I can feel my calves start to swell. Over the course of these rides I started to think a better measure of the effort threshold might be in order. In particular the combination of climbing, speed, etc might best be reflected in calories burned - in my case this appears to be approaching 1500. About 400 calories later, the swelling starts to become noticeable in the upper leg, often accompanied by the beginning of some knee pain. It is worth noting that for riding, I choose compression that is slightly looser around the knee to avoid pinching the connective tissue behind the knee - this can become fairly painful if I don't grade the socks correctly.
On this ride I did NOT stop part way and elevate my legs. This might give me a bit more range. I have done so in the few past long rides I have taken, generally by pausing at home for breakfast. I also did this during the trainer simulations of this ride. When pausing, it is usually about 60% of the way into the ride, trying to break before that 1500 calorie marker. I'll do some A-B testing of this strategy over the winter.
The problem that I don't have a solution for is that at some point in a long ride, my skin and the compression start to disagree which results in the skin tearing along the glue line. In the past I've accepted this as part of the cost of doing business (a handful of times, spread out in time), but in a multi day event, it became challenging to select a new place to glue the compression. I moved the glue point down a bit each day - below the tear point from the previous day. Where the problem develops is if the glue is on the meaty part of the muscle, the muscle flex causes it to lose grip fairly quickly - which happened each day while traveling home.
The creams many people use for saddle sores aren't really viable because if under the glue they compromise adhesion and if above the glue line they don't have any affect on the constant pulling. I might try some vertical adhesion, or some other pattern to distribute the stresses - without compromising the carefully graduated compression.
Somewhat related, for future reference and comparison, the discolouration at the lower end of the compressed area (compression starts at my toes and runs to the top of my legs).
Not shown, but saved with the above is the vein development beyond the reach of the compression. Currently at the top of the leg is a rippled vein about the size of a roll of quarters - maybe a bit longer. There were many smaller in diameter on my right leg until I started adding compression to my 'good' leg for seemingly harmless activities like driving (I previously used calf sleeves).