"Disclaimer: I received SIS isotonic gels to review as part of being a BibRave Pro. Learn more about becoming a BibRave Pro (ambassador), and check out BibRave.com to review, find, and write race reviews!"
Sometimes life is pretty cool. A prime example of life being pretty cool occurred recently. I was offered another opportunity to test and review additional flavors of Science in Sport (SIS) isotonic gels. During and since my initial trial and review of SIS gels, they have become my “go to” energy gel for endurance events and long training days so I was super pumped to try more flavors. This time around I received three flavors to try: salted strawberry, apple, and orange (75 mg caffeine). I was especially happy to see the caffeinated orange flavor in this round. I had previously tested the double espresso (150 mg caffeine) flavor which turned out to be one of my favorite flavors. However, the 150 mg of caffeine in every 90 calorie gel was a little too much caffeine for me if that was the only flavor I was using. Having the option to spread out the caffeine intake between gels was a very welcome choice.
During my first trial of SIS gels, I put them to the test at two last person standing events and was absolutely pleased with their taste, how well my body was able to process them, and the energy they provided. For this trial, I put them to the test again and used them as my primary calorie source for a 106 mile FKT attempt on the Batona Trail (22:46:42) in South Jersey. Once again, SIS gels delivered the sustained energy I needed for long strenuous effort. My energy levels never crashed with my steady stream of calories via the SIS gels.
Of the plethora of brands and flavors of gels I’ve tried over the years of running ultras and eating whatever brand of gel happens to be at the aid station, I’ve found that the flavor and consistency of SIS gels work better for me than any of others. Usually after a long ultra my teeth hurt and I am almost sick to my stomach of forcing down overly sweet gels with overpowering flavors. This doesn’t happen to me when I use SIS gels, even after 20-30 some hours of eating them on three occasions. The flavors are not artificial tasting like I find most other gels to be. The lighter consistency makes them easier and faster to consume than your standard syrupy gels which also means you don’t feel like you have to rinse your mouth out after eating them.
So what’s the deal with “isotonic”? Well, it’s the reason why SIS gels aren’t a syrupy gooey mess like the majority of other gels on the market. They are the first of their kind. To explain it in more detail, we have to review a little high school biology terminology:
Hypertonic: If a solution is hypertonic, it has a higher concentration than the fluid in the body. This means that water particles will have to be pulled from the cells into the gut to help it absorb and balance up this concentration. This slows down the availability of the energy from the gel and can bloat your stomach and be very uncomfortable.
Hypotonic: If a solution is hypotonic, it will have a lower concentration than the fluid in the body. This means that it will empty quickly from the stomach, but it will not contain much energy.
Isotonic: To be isotonic a solution must have the same concentration of dissolved particles as the fluid in the cells within the body, typically this means having a tonicity between 280-310 mmol/kg.
So what is the benefit of SIS gels having the same concentration of dissolved particles as the fluid in the cells in your body?
- They provide a quicker supply of energy to the working muscles than thicker, more concentrated gels.
- They’re absorbed without needing additional water.
- They’re easily digestible and light on the stomach.
Also check out what other BibRave Pros thought of SIS gels!