Irrespective of whether I’m carrying an inflatable or closed cell foam model, the one constant in my choice of sleeping pads over the years, has been that I always use mats that are no more than 3/4 length.
There are three reasons behind this decision:
1. Weight saving.
2. It uses up less space in my pack.
3. On-trail health.
The first two points are self explanatory. In regards to the third, the details go something like this………
I sleep with my feet on top of my backpack, which is filled with food bags and/or gear not being employed at night. Such a system aids in reducing swelling in the lower extremities after a long day on the trail, as my pack is usually slightly higher than my sleeping mat.
“Isn’t that uncomfortable?”
Personally speaking, no, though I recognise it’s a system that doesn’t work for everyone.
In my own case, I’ve always enjoyed sleeping with my feet slightly elevated. Before drifting off to the land of Nod, I try to make sure that the items inside the pack are evenly distributed, with nothing hard edged or pointy (e.g. food hydrating container or stove) directly against where I’m resting my feet/lower legs.
“Does it really make that much of a difference?”
Weight-wise, I guess we’re talking a saving of three to six ounces. In regards to on-trail health, I suspect that the discrepancy is not significant, however, it’s often small things combined with other elements in your backcountry routine (e.g. in this case daily stretching, eating well, pacing oneself, etc) that end up collectively making a big difference.
In my experience, 3/4 length mats are better for going down waterfalls, as there is less material to snag and/or flop around:
And also superior to their full-length cousins for paddling across frigid channels, as they are significantly easier to maneuver.
Note: Just to be clear, in regards to the bonus benefits, The Hiking Life team strongly advise against using an inflatable mat to go down waterfalls and a closed cell model to cross large watercourses. Horses for courses, people, horses for courses. 😉