Is tailwind sold in stores? Or has to be ordered from their website?

I'm pretty sure it's exclusively online. I actually got a sample in a Trail Box. 

If you look at the nutritional information on the label, Tailwind contains only sugars for nutrition/energy/calories.

What about the need for protein on longer runs? I don't doubt that the sugar gives you the energy you need, but the body needs protein, too, to maintain its biological functions, and to "repair" the muscles. If a person who does not exercise excessively needs about 0.8 grams of protein per kg body weight (assume: normal weight range) per day, why would Tailwind provide "everything you need all day" when you exercise (at a level that would be considered excessive by most nutritionists, thus requiring even more protein, like 1.1 grams per kg body weight or more)?

If you run, say, a 24 hr race, or a 100-miler, and you don't eat any solid food (or use some kind of protein shake or such), I'd assume the lack of protein will compromise your performance?

I have noticed that eating/drinking 20 or 25 grams of protein in ultras at around halfway point, or every 20 miles or so, gives me a nice boost, and I feel much better.

Anyone have more information on this?

another Perpetuem user (actually prefer the unflavored version)- it's the sole reason why I went to the AK pack, so I could carry two bottles- one w/ calories, one w/ water- I tried a double lumbar pack- it was OK, but not great, tried two handhelds- didn't care for that much, tried one handheld (w/ Perpetuem) and a vest pack w/ small hydration bladder- this setup was actually pretty good, but the AK is even better as if given the chance, I prefer to run hands free

I still get calories from blocks and bars, but I like sipping on the Perpetuem as I go- I usually get about two hours out of a 20 oz Perpetuem bottle

Couch, I've given a lot of thought to that as well.   I tried Perpetuem and my stomach did not do well with it. I also hated the taste. I might still give it another shot this summer (perhaps the unflavored), because I only tried it a few times during the spring. Hammer Gels are some of the only gels I can actually stomach, but I still hate the stickyness after a couple hours. Thus, I think that if I can replace the gels and electrolytes with a liquid substitute, and then supplement with solids at aid stations (as Jamezilla stated) then I might have a good long-term solution.

Regarding double bottle vests:  I have been thinking about ordering one or a few months and have been afraid to pull the trigger for various reasons, but mainly cost. I have a nathan vest now that works perfectly fine.  When you bottle-vest wearers go out with 2 bottles of whatever during TRAINING runs, do you bring the powder with you and refill water & mix on the run? Or do you park your car in a strategic place and just switch out bottles? I guess it all depends on the trail you run on. Obviously this will not be a major concern during a race.

I save the protein for after the run when I'm recovering.  When I cut back on protein during long runs and races, my stomach issues went away.

I have also found that the Perpetuem is a bit on the "heavy" side for me, I do better with Hammer's Sustained Energy, which has less fat and protein. But I definitely benefit from some easily digestible protein every 15-20 miles on long (30+ miles) runs. I found that "Proasis" protein drinks ( http://www.swansonvitamins.com/protica-proasis-protein-shot-clear-25-grams-6-2-9-fl-oz-liquid  ) work very well for me, it's a small, concentrated amount, I can drink it even when I'm nauseous, and it does not bother my body having to digest it. I buy it from my local grocery store (Wegmans), they have it on sale every now and then, $3 per shot.

You might try diluting the Perpetuem fairly much, e.g. one scoop in 20-24 oz. of water. I do that on shorter runs in the morning, when I haven't had breakfast, but I know my run will be hard, and I do well with that. Haven't tried it on very long runs yet, though. When I'm on very long, unsupported runs, I take a multi-hour bottle of Perpetuem with me, e.g. 4 scoops in 10 oz of water (which makes it a thick consistency), and this is harder for me to digest (and I need the extra water/more Heed for it anyway).

But a different product might work better for you, too. Trying things out is the only way to find out.

I acknowledge that for speedier athletes, digesting the protein might take away from their performance, but for me, the difference is negligible, and in the end, it helps me get through the run/race.

Anyone ever given it a thought what that constant (and daily?) sugar-water in your mouth for hours on end might be doing to your teeth?

http://www.mouthhealthy.org/az-topics/b/baby-bottle-tooth-decay.aspx

Couch, I've given a lot of thought to that as well.   I tried Perpetuem and my stomach did not do well with it. I also hated the taste. I might still give it another shot this summer (perhaps the unflavored), because I only tried it a few times during the spring. Hammer Gels are some of the only gels I can actually stomach, but I still hate the stickyness after a couple hours. Thus, I think that if I can replace the gels and electrolytes with a liquid substitute, and then supplement with solids at aid stations (as Jamezilla stated) then I might have a good long-term solution.

 

Regarding double bottle vests:  I have been thinking about ordering one or a few months and have been afraid to pull the trigger for various reasons, but mainly cost. I have a nathan vest now that works perfectly fine.  When you bottle-vest wearers go out with 2 bottles of whatever during TRAINING runs, do you bring the powder with you and refill water & mix on the run? Or do you park your car in a strategic place and just switch out bottles? I guess it all depends on the trail you run on. Obviously this will not be a major concern during a race.