Interesting, I even got a bit exited. Until I had read the study itself and had a look into the cited papers.
Case study, n = 1. No control group. No baseline data. From here on we know, the data and information drawn is not valid.
But well... it's still interesting, so further goes...
The case study suggests hiking to be exercise and compares to papers
including high intensities
In this case
Minutes with HR above 80 % HR = 28 min/day with 487 min/d of hiking.
What was high intensity again?
Quite a few of the cited papers have nothing to do with this case study eg.
Early et al. 2007
(meta study) which are in themselves questionable since some corner points like exercise intensity are simply defined with
light, moderate and high
. We have no clue what this means and if or how it can be compared to the thru-hiker.
It once talks about 5500 kcal/d in the introduction and once of 3315 kcal/d in table 1. I wonder what went wrong here.
Since I was baffled about the amount of vert gain/day rsp. per daily distance - number's more apt to the greater ranges than the Pacific Crest - I looked them up.
I you hike the PCT in 92 days, like the subject did, you gain 1621 m/d. Actually a bit less, since the subject jumped a total of 212 km of the total 4270 km. According to
https://pctmap.net/2014/03/04/elevation ... rest-trail and the PCTA the total vert gain is 149,175 m (give/take a little) and not as stated in table 1 of the paper 251,203 m. Probably the subject had used the Fenix in ultra battery mode during which the GPS signal pick up is rare, weak and wanders (under movement). Tracking in this mode leads to inaccurate readings. Again, I know this from own experience with Fenix and Instinct.
From own experience 8 h/d under similar circumstances (and distance/vert gain - remember, a bit less than 1621 m/d, not 2730 m/d) I (2 cm shorter than subject, mostly 2 - 6 kg heavier, lighter backpack, so total mass would come very close) I need about 3500 - 4000 kcal/day. I usually go with less and loose some body mass (mainly muscle mass when hiking) on longer trips (my max is 60 days).
My guess, 3315 kcal is the more accurate number for the subject, but they messed it up with getting elevation gain wrong in, weirdly, only one of two places.
Bone mineral density would've been really interesting, but once I read through the 4 numbers, I realised that there's simply no way of telling how significant the changes are.
The subject (individual) is a "highly fit", male "runner".
How often he runs and how his usual diet looks like - not a single word.
The subject could've kept a diet and running diary for the time between the data collection.
But again, nada. Well... one could say, the data can't be used anyways, so why bother at all...
A bit of a mess it seems.
No baseline measurements, just two data collections a couple of weeks pre and post hike, one single time. Of one subject. No confidence interval, standard deviation, nada.
Whilst interesting data, I wouldn't trust them since other, basic numbers are messed up too.
Just another academic trying to publish as much as possible to gain credits.
The subject itself seems interesting.
the subject performed daily push‐ups to maintain upper body strength, completing 282 push‐ups per hiking day during the first 56 days. On the 57th day, 1000 push‐ups were performed, after which, shoulder pain developed. For the following 13 days, daily push‐ups were reduced to 66 per day. After this, all push‐ups were discontinued in an attempt to preserve all energy.
Imagine his dairy (which he didn't keep) readings for day 57. "Woke up early. Slept well under stars [...] and during a quick wash, I felt the muscle loss, it's getting worse. I have to do more push ups! I'll do 1000!! That will save me from becoming a beanpole!!!"
Well, thanks Gairy, I had some fun and learned a few things during digestion of a huge (and as some may say unhealthy) breakfast. I'm off riding soon.
Let's just bear in mind to do and eat whatever we like and whatever goes with our very own health and environmental conscience and not what others believe is healthy or not for us, perhaps leading to an age of eg 89 instead of 85 y.