If you are considering adding carb powders to your training, here is something to think about.
09 Jul 2017
What Are They?
A popular trend within the bodybuilding industry is the use of intra-workout carbohydrate supplements.
We know that for intense bouts of exercise such as resistance training, carbohydrates are the preferred fuel source due to their ability to generate a lot of energy in the presence of very little oxygen. This is extremely efficient, especially when we are training hard but we also know that this reservoir can be tanked relatively quickly as we cannot store large amounts.
For reference, an average person may be able to store 500-700g (2000-2800 calories) of carbohydrates at any one time in the form of glycogen within the muscles and liver with trace amounts floating through the bloodstream. Fat on the other hand can be stored in virtually unlimited amounts and is the main source of energy for low intensity (heart rate under 65% of max), long duration activities such as walking or cardiovascular exercise.
We are always using both to some degree but the ratio will be determined on just how hard we are working. The higher the intensity, the higher demand for carbohydrates and the lower the intensity the more we rely on fat for fuel.
Fun Fact Detour:
It’s important to note that this simply implies what substrate we are using based on the activity and has no correlation to whether or not you lose body fat. Unfortunately, this is how the idea of a “fat burning zone” was developed and many misunderstood the practical application.
We virtually spend all day in the fat burning zone but this doesn’t mean we are burning body fat. For that to happen, we need to be in an energy deficit otherwise our bodies will simply continue using the energy we are providing through the diet.
Back to the article..
Now that we have a good basic understanding of how carbohydrates impact our performance, it does make sense to keep them as high as we can once we have met our protein and dietary fat minimums.
Does this mean we need to be supplementing with carbohydrate powders to get the job done?
As always, it depends.
Let’s dive in!
Who Are They For?
Although good for stimulating endurance beyond 50-60 minutes of exertion, we wouldn’t recommend intra-workout carbohydrate supplements to everyone.
However, there are several situations whereby they can be of benefit.
The first is for those naturally ‘ectomorphic’ body types. These are the guys and girls that find it almost impossible to gain, and even maintain, weight. Quite often, the cause isn’t necessarily that they have a very high metabolism, but they just don’t have the appetite to get the required calories in on a consistent basis.
If this is the case, simply consuming a carbohydrate mixture of around 30-60g of carbs alongside some liquid protein or amino acids can work very well. Also, it can be mixed and consumed during their weight training session, so it doesn't replace one of their meals and, depending on the carbohydrate powder, it shouldn’t be very filling or bloat them at all. As a result, it won’t impact the other meals in their day.
To keep their diet higher in nutrients, we would attempt to include more fruits and vegetables within their shakes as the more whole foods we can get in, the better from an overall health perspective. Fruits like bananas or mangoes work well as they provide a good hit of calories and taste great too. These shakes wouldn’t be recommended during their training sessions but can be incorporated into their overall plan to make sure they are hitting their micronutrients.
Long Endurance Training
If you are someone who is doing extensive levels of cardiovascular work, such as training for a marathon, a triathlon, cycling race or virtually any activity that is demanding you to exercise for 2-4 hours at a time, carbohydrate powders may be a very worthwhile investment.
Not only can they provide a quick supply of energy when you need it, but they have also been shown to reduce stress hormones and inflammatory cytokines that come with very heavy cardiovascular training. When you put your body through rigorous training for extended periods of time, you do temporarily expose yourself to higher chances of infection, leaving you immunocompromised during the hours post workout. When you have enough glucose available though, this “window” diminishes not only in length but also in magnitude.
Very Lean Individuals Who Are Dieting Hard
The third group may seem a little counterintuitive at first, especially considering that towards the end of a diet you want to be consuming as much food volume as possible but this could be a potential tool for anyone looking to hold onto performance as much as possible.
As you get leaner and leaner, things that didn’t really matter for the majority of your fat loss journey can start to have an impact in more indirect ways. For example, the timing of your meals doesn’t matter for fat loss just as long as you’re in a deficit by the end of the day.
True, but if you’re at the tail end of a diet running on fumes, you would be better off going into your training session with a meal or at least some intra workout drink vs nothing at all if you want to give your body a reason to hold onto muscle mass. In this specific scenario, meal timing definitely does matter.
Sacrificing 100-120 calories (25-30g of carbohydrates) to hold onto your performance can be a pretty good trade off if you really value your training but for some, it may not be worth it as that same amount of calories could get you:
130-150g of white potato
300-350g of strawberries
400-500g of pumpkin
500-600g of green vegetables
That is a lot of food volume which could be more valuable to you when dieting as managing hunger is a critical part at this stage.
Which Type is Best?
As with most intra-workout supplements, there are various different powders available to purchase on the market ranging from very cheap (pure glucose), to relatively expensive (Highly Branched Cyclic Dextrin, or HBCD).
Listed below are a few of the most popular of brands:
1) Highly Branched Cyclic Dextrins
This one is probably the most expensive, but for many, the most worth it.
The first reason being it passes from the stomach into the small intestine very rapidly, causing absolutely no GI (Gastro-Intestinal) stress whatsoever. This is a game changer, especially as hard exercise has been shown to slow down gastric emptying dramatically. If cyclic dextrins can bypass this, they have the capacity to get into the bloodstream more quickly which can ultimately lead to better performances.
The second benefit isn’t very well known, but it’s due to the structure of the carbohydrate molecule used. Typically, carbohydrates are a flat shape, whereas cyclodextrins are a cone shape. Due to this unique shape, they are able to pick up/carry other molecules with them. When combined with an amino acid source (whey isolate, BCAA, EAA etc.), it could potentially help ‘shuttle’ these nutrients into the cell. Thus, improving nutrient intake into the muscle tissue.
The research on resistance training is scarce but when looking at endurance training, highly branched cyclic dextrins do seem to outperform standard glucose solutions, especially when examining time to exhaustion. Fundamentally, you can go harder for longer without the GI discomfort to boot.
Remember the immune system benefits we mentioned above with regard to glucose availability reducing the risk of infection post workout? Well, branched cyclic dextrins seem to be better than just glucose alone in attenuating the stress response to exercise as this study demonstrated.
It’s important to note that this was only demonstrated in extreme endurance events (2 hours plus) meaning you don’t need to be fuelling your 30 minute incline walk!
Until HBCD came along, Vitargo was the ‘go-to’ carbohydrate source for most. It is said to have a ‘high molecular weight’, meaning that it pulls through the gut rapidly rather than just sitting there.
Due to its high molecular weight, it also has a low osmolality, which means that it doesn’t draw much water around it. This means it doesn’t slow down the rate of transportation and reduces the risk of stomach cramping.
Similar to branched cyclic dextrins, Vitargo can be very expensive (7-10 times more costly than dextrose) and unless you are training multiple times per day through either a combination of resistance training and cardiovascular training, such as crossfit then it’s probably not worth the cost.
Maltodextrin was hugely popular back when post-workout ‘recovery’ shakes were all the rage.
Maltodextrin is a complex carbohydrate by structure, but is high on the GI scale due to its short molecular chain and loosely bonded molecules of glucose – so it still offers rapid glycogen replenishment and increases in blood glucose levels.
Moreover, it’s cheap and it doesn’t taste terrible!
Dextrose is extremely similar in how it acts when compared with maltodextrin. Although it is derived from corn, it tends to taste very sweet as it’s pretty much pure glucose (sugar).
It is absorbed slightly quicker than maltodextrin, meaning maltodextrin may provide you with a slightly longer energy boost. As these differences are very minor, a lot of athletes like to mix the two in a 50:50 ratio to get the best of both worlds via a quick uptake and a longer time course in the blood.
Most find, as the quantity increases, that both maltodextrin and dextrose can cause some abdominal bloating. This is likely due to their molecular weight and higher osmolality when compared to HBCD & Vitargo.
The main attraction from these last two carbohydrate powders is definitely the cost. Even though they may not stack up as well in comparison to HBCD or Vitargo from a performance standpoint, if you are only focusing on weight training as your primary mode of exercise along with doing cardiovascular work for general health and/or fun you won’t be missing out on anything special.
Weight Training Only
If you were looking to optimise your weight training workouts through carbohydrate powders, either of the supplements mentioned today would not differ too much from each other. Granted, the HBCD/Vitargo supplements may be easier on your stomach but you can easily circumvent this by having your carbohydrate solution 20-30 minutes prior to your resistance training workout to minimise the negative side effects.
We would recommend going with dextrose or maltodextrin here.
Early Morning Workouts
If taken on an empty stomach with amino acids, there should be virtually no stomach issues whatsoever and funnily enough, this is the only time that carbohydrate powders have the potential to be beneficial from a performance perspective.
If you train in the afternoon or evening, you will have enough carbohydrate stores from the food you have been eating to fuel your workouts adequately.
We don’t see any additional benefit in opting for the most expensive powder here so sticking with dextrose/maltodextrin would be more than sufficient.
Heavy Endurance Training
For those wanting to take their endurance performance and recovery to the next level, HBCD or Vitargo would definitely be worth the investment as the most promising research on carbohydrate powders has been done in this field.
Due to the extensive training volumes, you want to be able to consume carbohydrates in a way that isn’t going to cause excessive gastric upset due to the impact that strenuous activity can have on the gastrointestinal system.
Unlike amino acids that once ingested have different roles to play within the body that pertain to recovery and repair, all carbohydrates will be converted into glucose and then stored either stored as glycogen in either the liver or muscles, or sent throughout the bloodstream to provide energy to important organs such as the brain.
Carbohydrates will always be the preferred fuel source for high intensity exercise meaning we should aim to keep them as high as we can within the parameters of our overall diet and goals.
With that in mind, for the most part all of the above will end up essentially doing the same thing. The difference between them lies within the delivery, rate of digestion and potential for bloating.
For most people, an intra workout supplement is simply not necessary to get the most out of their training but if you do want to give them a shot, use the above guidelines to help steer your decision based on your training goals.