SiS Beta Fuel – How much the pro’s take – 120g CHO/hour toleration

SiS Beta Fuel – 3 gels/hour

Science in Sport, SiS, recently cited a study in the Journal of Applied Physiology that strongly suggested we can all tolerate more carbs as we exercise.

Even in hard, 3-hour rides @90% LT, it was found that 50% of the supplement’s energy was oxidesed and that was irrespective of the format of product used – gel, chew, liquid or mixed. No carbs crossed over to fat and minimal stomach distress was reported (GID). The study used 9 trained endurance athletes with a VO2max of at least 58.

Caveat: These findings were specific to SiS Beta Fuel product which uses dual-fuel glucose/fructose in a 5:4 ratio (1:0.8)

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Forget 2:1 Glucose Fructose gels, you really need 5:4

Why This Is Important

Carbs fuel your workouts and races. You have quite limited cab stored in your body in your muscles/liver and once they’re gone, they’re gone. Well, kinda. You can replace them by eating and by converting fat to energy but the former happens at a lower rate than you need and the latter is even slower.

Thus you have no choice on race day but to get replacement carbs through eating. OK, they’ll get through to you slower than you’d like, so you have to optimise their intake.

The Pro’s actually use this stuff…Look!

The first thing you should do is to consume both fructose and glucose as these can be metabolised by two parallel processes. You’ll probably find that your current own-brand gel or High5 gel only contains glucose and maybe a tiny amount of maltose, which is entirely different to fructose. So a simple strategy is to eat a banana to use the fructose pathway. However, if optimised consumption & performance are important to you then SiS have shown the exact ratio of glucose to fructose to be 5:4. You can approximate if you want to, it’s your call.

Next, if you use SuperSapiens you will be able to quantify that one gel kicks into your bloodstream after about 20 minutes. You’ll also be able to see when its effect goes. That will happen quickly if you are training/racing hard!

Must Read: Supersapines Detailed Review

Supersapiens says that the performance zone for blood sugar is usually above 110mg/dL I am certain that my blood sugar often falls below 110mg/dL when I exercise hard.

Do your blood glucose levels fall below performance zones? Carb availability might not appear to be a problem for a while as you eat into your carb stores, so how do you know? Does your body subconsciously dial back your effort or change the perception of difficulty? Those will be personal to you and your abilities but I’d bet that most triathletes and cyclists don’t eat enough carbs either without realising or because of a physical intolerance to the type and quantities of carbs they eat.

More Info:

Here’s a real example of the effect of a gel on my blood sugar at rest. It gets into my bloodstream after about 20 minutes and peaks after about an hour (a further 40 minutes). If I were exercising, the peak is lower and sometimes sooner.




Back to the SiS Study

Even after three hours of sustained effort, 50% of energy used was from the Science in Sport Beta Fuel, with no cross-over from carbohydrate to fat usage taking place.

Infographic: More info here on the Study’s findings in a pretty graphic.

More Thoughts

One gel per hour is probably not enough on race day and 3 (SiS Beta Fuel) is probably the maximum for most of us.

Ingesting more carbs than you currently consume might make you faster for longer. Though you would expect a study linked to a sports gel company to tell you that.

Anyway, the point is that the pro’s might get an edge by increasing consumption and previously recommended levels might be too low for many of us. Don’t forget the study used athletes with VO2max as low as 58…that’s like many of us.

  • Gastro-Intestinal Distress is unpleasant and can ruin your performance and enjoyment of training and racing. Experiment with the format and volume of carbs that best suits your body
    • I do this: Swilling a gel around inside your mouth can reduce GID. This starts digestion earlier.
    • If you get GID consider a mix of fuel. Solids can reduce GID. A competing gel by Maurten, expands in the stomach to mimic the effect of solids.
  • Rehearse fuelling strategies prior to the event using similar intensities, durations and the same supplement.
  • Start fuelling right from the get-go. Or even before the race starts.
  • Races under one hour do not need a gel but one gel, or its equivalent, might still aid performance and probably won’t have a negative effect.
  • 120g CHO/hour is 3x SiS beta Fuel gels (40g/gel) or 1.5 powder sachets (80g/sachet or bottle).
    • Or 1 sachet + 1 gel/hour.
    • 120g is a maximum. So work your way down from that to find your optimal level.
  • You might be concerned about weight gain from too-frequent supplementation. Perhaps look at your Garmin/Polar to see how many carbs they thought your exercise burnt and compare that with what you consumed.
  • SiS beta gels are not cheap. I don’t think you’ll find a cheaper dual-carb brand (tell me below if you know one). If you get on the mailing lists of the nutrition companies they are very good at mailing out offers but they tend to be either for products you don’t really want or at times of the year when you don’t really need them.
  • If you are on a budget then you will have a carb strategy. But for those few weeks leading up to race day the extra cost of a quality gel like SiS Beta is trivially more than others in the grand scheme of things.


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