I did the hike the NPS warns people not to do. Plus, two shocking revelations!
The National Park Service is quite explicit: "Under no circumstances should you attempt to hike from the rim to the river and back in one day!" OK, they're talking about the North Rim and I did the South Rim, but play along.
But, before I get to the trip report, prepare yourself for the first shocking revelation: Chad Bravo, Master Hiker, does not exist. More precisely, I am Chad and he only exisits in my imagination. (See the hilarious earlier episode where "Chad" hiked 2/3 of the way into the Grand Canyon about a month previously.)
This time I just hiked down the South Kaibab trail and then hiked back up the same way. I had to park 3/4 of a mile away from the trailhead, along the road at Pipe Creek Vista. I then walked the largely flat Rim Trail to the trailhead; the entrance to that paved trail was right across from my car. That made the total trip 17.5 miles RT with ~5,000' of gain. I did most of the up leg at night and I was able to avoid using a headlamp until I hit a dark spot. Aside from a few near the bottom going to Phantom Ranch or the campground, I only saw one person on the up leg: a guy who was going down to the River without using a light (he said he had one). The half moon was bright but I don't know if I'd want to do a downhill like that without a light.
Bearing in mind the my heart rate zones are (I believe) a little too low, I was in Zone 2 for almost all of the down leg, and Zone 3 for almost all of the up leg. I only spent a few minutes in Zones 1 or 4. Obviously I'd rather be in Zone 2 throughout, but I also didn't want to get back next week. As it was, whenever I went into Zone 4 I briefly stopped. In addition to that, I stopped at most of the named locations to stretch, except I went by Ooh Aah Point without noticing it.
On the way down I wore my cellphone in a wrist strap with the Polar app open and it accurately recorded my path. However, I put that away for the up leg because it was running down the battery too much. As a result, while it recorded my heart rate accurately on the up leg, not so with the track.
I carried 2L of water with electrolytes, 2 (lightweight, rechargeable) headlamps, 2 puffers, a pair of convertible mittens plus insulated shells, a ski cap, a balaclava, and microspikes. I was wearing leggings under my shorts. All of that seemed like it wouldn't be that necessary as long as I was in the Canyon. However, as soon as I got back to trailhead it was literally freezing so I used some of it for the trip back to the car.
It got down to 24F on the trip out of there and I was speeding as usual. I blew past a local gendarme about 20 MPH over the speed limit. I slowed down as quickly as possible but he followed me for a mile before pulling me over. Apparently he hadn't got a good reading because the pretext he used was he thought I was impaired because I'd drifted over the white line (I hadn't). After admitting that I wasn't impaired, he ran my plates and let me go.
Despite that unfortunate incident (to the extent escaping a speeding ticket is unfortunate), it was a great trip.
Now for what you've all been waiting for: the second and even more shocking revelation: THERE ARE NO ICE CREAM CONES AT PHANTOM RANCH! In fact, they seemed to think it a fanciful idea. I don't know if they had them at one time, but it certainly would be possible. A mini freezer weighs about as much as a heavy backpacking pack so could be easily strapped to a person or a mule. That could be easily driven with a solar panel or two. Maybe I'll set up an ice cream stand down there or something.
ADDED: I was able to completely avoid fast food during the whole trip. Not only that, I tried to avoid junky food altogether. However, on this hike I wasn't exactly dieting. I almost completely finished a 6oz pouch of peanut butter (1000 cals). I had some pepperoni (not exactly healthy but at least calorically-dense), a small high fiber tortilla, two packs of gummies (for sugar, 70 cals each), a fruit bar (not so calorically-dense), and a Honey Stinger that I got at the Ranch. They sell merch but only with their name on it; if they'd had a shirt about the hike itself I probably would have bought one.
While my muscles weren't that tired the next day, my feet were. Despite that I had halfways considered hiking Kelso Peak on the way back. As usual, I got a late start and finishing an unfamiliar offtrail desert hike by headlamp didn't sound like a great idea. Plus, Google Maps tried to route me down a single lane, rough, rocky dirt road as a "short cut". Getting stuck on that road would not have been great either. So, I gave up and just went to Kelso Depot.
ADDED 2: My pack wasn't that heavy, but I also had my SpotX; a Sawyer squeeze with the water pouch + an empty water bottle that fits it as a backup; hand sanitizer, TP, and a couple Restop bags; caffeine packets and ibuprofen (neither of which I used); and probably some other things I'm forgetting. This might shock some and it's definitely not that healthy, but I probably only drank about 1L of water on the whole hike. I pre- and post-hydrated and was clear and copious. I need to become a Hydro Homie I guess.
ADDED 3: I also had a Frogg Toggs rain jacket.