Our nutrition aisle is by the register at the front of the store. Triathletes mostly come in for some CO2, a valve extender, a carbon fiber bottle cage wing, whatever. On their way to checkout they quickly scan the nutrition aisle and reluctantly grab "something" almost at they're making a choice on the lesser of evils. One customer said "this one made me throw up at my last race and this one over here made me bloated on the entire bike ride".
Different things work for different people, when prompted I tell them that I'm a fan of real food and not big on gel or bars, but then again I'm not racing Ironman distance races so I'm not motivated to deperately grab calories anyway I can. This isn't to imply that the long distance triathlete is relegated to junk and can't eat better. As a neuroscience and physio graduate I used to talk to them about how our body absorbs the protein in food sources easier than in supplement form. The small intestine absorbs amino acids and has peptidase enzymes on it's surface that splits most dipeptides and tripeptides into single amino acids.
A few of these dipeptides and tripeptides escape digestion and cross the digestive tract wall and enter bloodstream. These athletes would get conflicting information from nutritional faddists whom fail to realize that most proteins are broken down to amino acids before absorption. They urge people to eat enzyme supplements, unfortunately these enzymes in foods are digested in the same manner proteins are. Digestive enzymes are the only things by design that prevents them from being denatured or digested.
Some products are marketed based on their amino acid content others on their high carb or protein content and although you will need protein at some point in your long ride I'm not convinced you should be getitng it all from your bottle. Drink Skratch and eat real food (tons of great recipes on Skratch's blog and in Allen Lim's book )
So why do I like Skratch?
High Quality All-Natural Ingredients
No artificial anything
Optimal Sodium for exercise
Actual fruit used for flavor
Less sugar, more electrolytes
Environmentally conscious packaging (which they say will be improved again soon)
It has only a trace of sugar, so it doesn't set off wild insulin spikes causing "sugar high" and "sugar crash" and is easily digested
Essentially less is more. I could ramble on about how a product is "laterally stiff but vertically compliant" but I feel all you have to do is try it and you'll see why it's my favorite nutritional drink.
Reach out to me at firstname.lastname@example.org and I'll get you a sample.