Say you and your clothes weigh 180lbs and your pack weighs 45lbs. That is 225lbs your legs must move along the trail.
My new favorite metric is taking total body weight + total starting weight of all gear, worn/carried/in pack + consumables, etc. Let’s call this W.
Now using some type of body composition measurement device, maybe a bioelectric impedance scale, and determine your skeletal muscle mass. Let’s call this M.
Now determine your Ultralight Rank (U):
U = M / W
So take a hypothetical human with a bodyweight of 150 lb, M = 60 lb, dry weight of gear = 15 lb, packed for a weeklong trip with 15 lb of food.
That makes W = 150 + 15 + 15 = 180, so U = 60 / 180 = 0.33. What a rockstar. ULAF.
Now take someone with the same amount of muscle but now he’s kind of a fatter fellow, which means his clothes are a little bigger, so bodyweight is 170 lb, M = has 60 lb, dry weight of gear = 17 lb, food = 15 lb.
That makes W = 170 + 17 + 15 = 202, so U = 60 / 202 = 0.30. My god, that’s low.
Hopefully, this post emphasizes the folly of numbers. Maybe it even validates Bruce’s base weight silliness claim.
In reality, if you are looking to really study the metrics behind lightening your pack, stick with total gear weight. Base weight does seem pretty ridiculous. The idea that “the gear you wear shouldn’t count because it’s closer to your center of gravity” really doesn’t hold up to a strong scientific argument. When you do the calculations, see that there are very few meaningful differences, you start to realize that the argument is a bit contrived and kind of dumb – which frees you to take all that crap out of your pockets and put it back in your pack đ