The Bottleneck Effect

For Endurance Athletes, Carbohydrates (CHO) form the primary source of energy. In order for athletes to sustain long, intense, and challenging levels of physical endurance, CHO ingestion becomes critical, and defining. Our endogenous CHO stores can only take us so far, thereafter, we must rely on exogenous sources of CHO (such as the Unived Elite Gel and Elite Drink Mix) to ensure we receive adequate amounts of CHO which our body can use as fuel, permitting us to continue our endurance activity. CHO ingestion not only delivers energy for physical activity, but it is also a source of fuel for the brain, our control panel that decides how best the internal systems should work, based on the fuel they have and the challenge that lies ahead.

So does this mean that the more CHO we ingest, the better off we are? No! Although one can keep consuming CHO (until you feel full), there is a specific amount of CHO that our body can oxidize per minute. When we consume more than what we can oxidize, it leads to symptoms such as GI distress, stomach pain, and vomiting. We call this the bottleneck effect.

What is the bottleneck effect?

Simple carbohydrates are those with a high glycemic index. High GI CHO are typically broken down instantly, and provide an instant surge of energy. Most energy gels & energy drink mixes across brands, are formulated with simple carbohydrates. Simple CHO is oxidized in our body via the SGLT-1 pathway, at the rate of 1g per minute. That means, we can oxidize 60g per hour. As we know, 1g of CHO is 4 kcal. So, 60g of CHO delivers 240kcal, per hour, as energy for our body to utilize.

When athletes consume more than 60g of simple CHO per hour, it begins to pile up, and as the hours roll on, we find ourselves with an excess amount of CHO, much more than what we can oxidize. This phenomenon, is called the bottleneck effect. It is commonly experienced as GI distress, stomach pain, or vomiting.

I need more calories per hour – how do I prevent the bottleneck effect?

You cannot consume more amounts of simple CHO per hour, and still hope to steer clear of the bottleneck effect. Although, for full marathons, ultra-marathons, ultra-distance cycling, and triathlons, our caloric needs are typically higher, and we need to rely on a constant supply of instant and sustained energy release.

To address this, we looked at how our body receives simple & complex CHO when consumed together. Complex CHO, are low-GI carbohydrates. These sources of CHO are known for their slow & sustained energy release. Complex CHO is oxidized in the body via a different pathway, named GULT-5.

When we consume simple & complex CHO, in a 2:1 ratio, the body oxidizes the simple CHO via SGULT-1 at 60g per hour, and the complex CHO via GULT-5 at 30g per hour. This consumption of multiple transportable carbohydrates in a 2:1 ratio, allows us to oxidize upto 90g of total CHO per hour, thereby, delivering 320kcal, per hour.

This is the science behind the Unived Elite Gel & Elite Drink Mix formulations.

Elite Gel & Elite Drink Mix – 2:1 Ratio

The Elite Gel & Elite Drink Mix are both formulated with a 2:1 ratio of simple to complex CHO. Both products offer 30g simple + 15g complex carbohydrates, per serving. This ratio permits us to maximize our CHO intake, and thereby, maximize our energy availability.

Through this formulation, we can by-pass the bottleneck effect that consuming only simple CHO may cause. We can maximize our energy stores, and thereby, give ourselves the most complete nutrition availability to support an optimal performance.

You may read more about the Elite Endurance Line here

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