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Review: a Brutal test for GlycoSource


Launched this summer, GlycoSource from UK company Science Fitness has already started to make in-roads into the über-competitive endurance sports nutrition category. As the first product in the Science Fitness range, GlycoSource is a powdered drink mix. It is available in Mandarin Zest, Very Berry and Caribbean Crush flavours, in both 750g pouches and handy 25g single-serve sachets.

Having picked up a bunch of 25g sachets, we put GlycoSource through its paces leading up to a race in North Wales – the Brutal [more on this later].

With an initial test of GlycoSource at the London Triathlon expo, it is apparent that the brand has a distinctive taste. The team at Science Fitness note that the slightly bitter after-taste is due to the amino acids in the product. Sipping a sample of GlycoSource at its expo stand in London – the taste wasn’t exactly pleasant, with a similar palate experience to drinking energy drinks such as Red Bull.

However, when glugging back GlycoSource in a 500ml bottle a few weeks later the taste became less noticeable throughout a long ride; and the citrus kick from the Mandarin Zest and Caribbean Crush flavours in particular helped offset any unpleasantness.

There’s also something to be said for the distinctive taste, in that it’s not too syrupy – and, as in the case of Red Bull, while GlycoSource might not ‘give you wings’ there’s perhaps a sense that the amino acids present in the product are actually doing something.

Glycogen a go-go!
GlycoSource’s formula consists of two types of carbohydrates, whey protein and amino acids. It is billed as the first and only commercially available nutritional supplement that has been clinically proven to increase glycogen levels in both the muscles and the liver – an internal process that is vital to performance and especially to recovery after exhaustive exercise.

Glycogen is the body’s most important short term and immediately accessible energy reserve. It is how carbohydrate is stored in the liver and muscles and provides vital fuel during exercise. However, its quantity is limited. As athletes train or compete they naturally deplete their reserves of glycogen. When it is almost used up, it is no longer possible to perform at the same level and athletes risk hitting the dreaded ‘wall’.

Science Fitness notes that… ‘many other leading energy drinks and bars that claim to top up glycogen levels are based on the generic principle of ingesting carbohydrate at regular intervals, or carb-loading, and may lack clinical evidence of their efficacy. It has also been proven that there is a limit to the amount of assistance carbohydrate alone can provide.’

Impressively, the clinical trials conducted by scientists at Leeds Metropolitan University showed that GlycoSource replenishes glycogen 30-40% faster than pure carbohydrate formulations. For athletes who frequently train and compete, building up glycogen levels to the optimum level quickly offers a huge competitive advantage, allowing them to be at their best with minimum downtime.

Science Fitness adds that ‘athletes who regularly use GlycoSource can also expect to experience a 35% increase in endurance capacity.’

Also worth noting, the combination of ingredients allows GlycoSource to deliver this performance gain using 44% less carbohydrate. This is seen a huge benefit for athletes competing in triathlons and other endurance events, offering them the ability to maintain their body’s energy reserves, whilst keeping their carbohydrate intake at the optimal level.

The Brutal
Having got used to the taste, general consumption and gut feel of GlycoSource ahead of the Brutal Half event in Snowdonia, Wales, two bottles were put through their paces on race day, on Saturday 20 September.

After a fitful night’s sleep in a van on a field next to the transition area, a few sips of GlycoSource (and that slight amino acid kick) helped act as a wake-up call for the early morning start.

The Brutal consists of a middle distance (half), a long course (full)… and an ultra distance (double) [the latter being for the superhuman or clinically insane]. The event is based out of Llanberis, Gwynedd, North Wales on 20-21 September 2014. It starts with a cold lake swim in Llyn Padarn, before a 28.99 mile bike lap course and an equally ‘brutal’ run.

The half athletes complete 2 laps and two ascents of Llanberis Pass, which means the Brutal Half distance ride gets close to 60 miles – a few miles extra on a standard 70.3 middle distance course. The full athletes complete 4 laps and the double athletes complete an astonishing 8 laps of the 29 mile loop.

The run has 2 sections, a 5.2 mile lap that goes around Llyn Padarn and an ascent and descent of Mount Snowdon, which is approximately 9.5 miles from transition and back.

With such a tough course, nutrition becomes ever more important, particularly as there are limited feed stations at the Brutal event. On race day, the GlycoSource certainly didn’t cause any gastric distress. The taste wasn’t too sickly and it was easy to glug back both bottles during the ride.

A further bottle for the ascent of Mount Snowdon would have been appreciated, but, sadly, wasn’t to be – due to poor preparation and a stupid rush through transition.

So, in summary, while nutrition may be down to personal preference, with GlycoSource there’s at least a sense that some good science has gone into the brand. The product is after all the result of a collaboration with Leeds Metropolitan University, which does add to a sense of efficacy…

Roderick King, Carnegie Professor of Sport and Exercise Biochemistry at Leeds Metropolitan University, led the research and clinical trials for GlycoSource. He explained, “Typically, the body cannot absorb and utilise more than 50-70g of carbohydrate per hour. If athletes take in more than this amount the excess sits in the GI tract rather than absorbing into the bloodstream, which can cause uncomfortable bloating and stitches during performance.”

GlycoSource may even have helped with a top 10 finish (just!) at the Brutal Half, or that could have been down to luck on the day!




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