Dr. Stacy Sims, Michael Folan and Dr. Allen Lim

Which hydration product is better than the other? It's a tricky question without a definitive answer. What works great for one user can cause GI distress for another. What tastes great for some will elicit the proverbial bitter beer face in others. But this much we do know, testing endurance sport hydration drinks involves more critical analysis than the good old Pepsi Challenge.

In this final installment of our Meet Your (Drink) Maker series, RoadBikeReview talked with three experts in the field of endurance sports nutrition (Osmo's Dr. Stacy Sims, Skratch Labs founder Dr. Allen Lim, and Infinit Nutrition president Michael Folan) and found out their top tips for testing one hydration product against another.

And just for kicks, we also asked about their overall opinion of the endurance sports nutrition industry. As you can imagine their answers were not all positive.

[Editor's Note: To learn more about out expert panelists, their products, and their companies, check out Part 1 of our Meet Your (Drink) Maker series. Then take a look at Part 2 where they give their top tips for post-ride recovery]

All personal biases aside, walk us through how you personally would test one endurance sports hydration drink versus another.
Osmo's Dr. Stacy Sims: First off, I would do the test sessions a week apart and make sure that what I did two days prior to the testing day was exactly the same. That means hours of sleep, food I ate, hydration, everything. You need to go into each testing session as standardized as possible. Also I would do the test at the same time of day each time.

It's also to match calorie consumption during the test. So if you're testing a product that's a fuel-in-the-bottle product, it will be higher in calories than a product like Osmo. So you will have to top up your calories with blocks or gels.

For the test session itself, do a easy repeatable time trial or hill session, and record power output, heart rate, and subjective measures like how your legs feel, your stomach, and how your recovery goes. That means do you have to pee and how often, how your stomach feels afterwards, and then the next morning, how much you weigh and how you slept. Take all these measures into account and you'll get a good idea of which product works best for you.

Skratch Labs founder Dr. Allen Lim: The easiest way - and the only true metric that we consistently use - is to ask yourself how you feel. If something makes you feel like crap don't use it. Another way to think about it, and this is one of the things so weird about the sports nutrition world, is would you be okay using a product while sitting on the couch all day. If the answer is no, why would it be okay when riding the bike all day.

So maybe the litmus test is to take these various products, put on the season 1 DVD of Breaking Bad, and then start drinking. If you feel like shit at the end, then maybe those products are not so good for you on the bike. The fact of the matter is that exercise is a high stress environment and puts high stress on your GI system. So if something ends up not feeling right to you when you are not stressed or exercising, I'm hard pressed to believe that it is going to be better when body is at heightened state of stress.

Some other basic metrics, is to simply try to figure out if you are going faster, and there are a lot of ways to measure that. That may be an actual change in performance. That may be a change in how your gut feels. The bathroom scale also works well. A good product typically means you drink more and tend to not lose as much body weight because you want to drink. So weigh yourself before and after each ride. If you don't lose much weight, that means you are drinking more, which is a hugely valuable metric because it represents a decrease in dehydration, or an improvement in hydration. Also just look at your power meter if you have one. The more dehydrated you are the worse you will perform.

While I was working with the Garmin team, we were constantly weighing athletes before and after their workouts. The guys who lost less weight were the ones who were more on top of their hydration and ended up doing better and feeling better than the guys who lost more weight. If I can keep someone from less than 3-percent dehydration weight loss, odds are they will have a good day.

Bottom line is that you need to experiment. At Skratch we don't make claims that we will change lives or lead to massive improvements. What we make is an all-natural sports drink that replaces what you lose in your sweat. From a practical standpoint, I just don't believe in the one size fits all idea. Sports drinks must be used in the context of what else you are doing, so take it upon yourself to learn what works for you.

Infinit Nutrition president Michael Folan:
I think duration is what really separates products. There are a lot of drink products out there that will work for a two-hour ride. But when you start going long, that's where the products will start separating themselves. My challenge to athletes would be to take the appropriate Infinit endurance mix, men's or women's formula, and go ride your bike for 6 hours with nothing in your pocket. Just drink the stuff and ride your bike. I always get the same reaction. I wasn't hungry because Infinit has small amounts of protein. There's no magic to our formula. Protein is an appetite suppressant. So if you are not hungry when you get back, you don't bonk and your energy stayed up and was consistent, then you'll know.

I understand that we are very different because we take the guesswork out of it, and stop people from messing up and eating too much and bloating and feeling like crap. We remove that variability.

Last question: What is your opinion of the endurance sports nutrition industry as a whole?
Osmo's Dr. Stacy Sims:
Well the reason I am where I am is that since my personal racing days started back in late 1990s, I couldn't find anything that worked for me. So I started making my own product. Then when I stopped racing, I kept making things for teammates. That was driven largely because I feel like most of the product out there is based on marketing, not real science. There is a lot of misrepresentation is this market still.

Skratch Labs founder Dr. Allen Lim:
I got into this business because I felt there were problems to be solved within the industry. I wanted to find better solutions that the industry was not yet creating. I feel like the industry is improving, but it's still reflective of the food industry as a whole. I think the food industry for a while went through a very intense pre-packaged approach. Now that is changing with a greater push to whole and natural ingredients. You see the same thing with energy bars. It went from athletes eating real food, to athletes eating Power Bars, to athletes eating Clif Bars because Power Bars were so processed, now to bars that are more organic and even to what you see with our new Portables Cookbook, which is offering ways to go back to more natural foods.

Infinit Nutrition president Michael Folan:
Overall I think it is getting better. I mean I was talking about things like osmoality a long time ago. We've been stressing isotonic solutions and osmoality for seven years now. So I am thrilled that people like Allen and Stacy are confirming what we have been saying for a long time. At the same time, there is still some fairly old technology out there. One company that I wont name specifically, I think their technique of multiple carbohydrates maxes out the amount of calories your body can absorb. But overall the science is moving in the right direction. But we've been there for a long time and I take pride in that fact we were the first to talk about osmoality. But I do think that overall the products available today are far superior than what was out there 5-10 years ago.