Thursday, June 6, 2013

Product review: PowerBar Energy Blasts

Off day today for me- no running (well, maybe I'll go for an evening run if time allows, no promises though!) as tomorrow is a big day in my career and I have lots of prep to do for it.  Exciting stuff, I'll share after the big day :)

For now, let's talk about sweets!  My favorite type of candy has always been on the "chewy" end of the lickies-and-chewies spectrum...those big bins of candy at bulk stores?  I love me some cola bottles, cinnamon bears, peachy penguins, green apple frogs...really anything made by The Happy World of Haribo is at the top of my list, so it's no small wonder that I prefer gummy-type exercise sweets over gels.  My local grocery store stocks Power Bar Energy Blast Gel-Filled Chews.  I usually find them on sale for $1.00 per bag, and in three flavors each with a different level of caffeine:

Raspberry is my favorite and even has some vit C
So what is the big selling point here?  How are these better than a handful of jellybeans?  PowerBar touts their proprietary C2 Max energy blend...which is just a 2:1 glucose:fructose (fruit sugar, honey, corn syrup) sugar ratio.  These monosaccharides are very similar (in fact, glucose + fructose = sucrose, aka table sugar) but the reason they are included in this proportion in these Power Bar Energy Blasts is all based on these guys and their time-trial of cyclists:


Currell and Jeukendrup reminded me that the transporters that take nutrients from your intestine to blood stream come in many different permutations.  In a very simplified manner, when there's a lot of glucose to be put into the blood (ie, after a meal), the glucose transporter (SGLT1) can get backed up with glucose traffic.  When glucose and fructose are combined, the fructose uses its own separate transporter (GLUT5) which is off limits to glucose, and everyone can get out of the intestinal lining and into the blood more efficiently via the backdoor from the intestinal cells into the bloodstream (GLUT2).  This is especially important in exercise as we need energy more quickly and don't want to wait for glucose to file out.

The researchers determined that a ratio of 2:1 glucose:fructose (1.2g to 0.6g) was more effective (an 8% decrease in the amount of time it took the cyclists to complete their cycling time trial as compared to 1.8g of straight glucose (which showed a 10% improvement over the placebo group who just had water without carbohydrate).  The scientists also indicated that the ingestion of the glucose:fructose blend staved off the body's need to use liver glycogen stores, allowing for these stores to be accessed later in the time trial.

So this is maybe how PowerBar formulated the 2:1 C2 Max blend.  I am glad to see there is real science behind it.  Do I personally need a perfect monosaccharide blend?  Nah, I am not nearly on that end of the performance curve.  In my "research" (sample size: me) I do notice that after having some gels or candies after about an hour into a marathon or century cycling event that I perk up a bit.  I also feel more energized after having regular foods, too, like a few graham crackers, or sips of carbohydrate beverage, so I know there's something to it and it's not particular to fancy lab-created food blends- in my case, it's probably a combination of the added glucose/fructose and a placebo effect.

I like a chewy candy while I run.  It fights boredom and doesn't gag me like some of the gels which seem more like a dentist's fluoridated sealant paste.  It's also easy for me to unwrap a few packages of gummies pre-race and put them in a small sandwich baggie and tuck into my sports bra or shorts pocket which doesn't cause the same level of underboob chafe as the scratchy edges of the gel packs.  Plus, it's easy to share a few chewy candies with a stranger, don't get me wrong, I love people and all, but I'm not letting all y'all have a quick suckle on a shared PowerBar Gel as you run past.

I'll continue to buy this type of stuff for my longer runs and races.  On the road bike I can pretty much dig into leftover Kung Pao chicken and not suffer tummy trouble.

Does anyone know more about this fructose/glucose nonsense?  What's your favorite pick-me-up during a run?  I'd love a diagram or at least an interpretive dance of the intestinal luminal cotransporters...