The Spectrum of Sugar

The spectrum of sugar: a discussion of fueling for rides, training, and racing performance.

While writing this article I am returning to the US after our first Team EF Education coaching camp in Beuda, Spain [March 22]. The weather was not amazing for this camp, we timed it perfectly to coincide with some of the coldest and rainiest days the region had experienced in months. In spite of this we had a very productive and fun camp with lots of teaching moments. I ended up with nearly 23 hours of riding in 5 days on some of the most beautiful roads in the world, met some great people, stayed at a super nice property and ate great food, so there is nothing to complain about.

We worked on many aspects of cycling, but one of the topics most frequently discussed was fueling and hydration for hard training rides. My Team EF Coaching colleague Zack Morris was on a mission to teach our riders how to fuel for this type of riding. The types of rides most often done during this camp were steady aerobic endurance pace over rolling terrain, with climbs of 45 min at race pace in the second half of the day. These types of efforts require a very specific fueling strategy in order to maximize the benefits this training.

Many of my listeners may have heard me speak unfavorably about the use of gels and mixes during training on my podcast, and I am not here to reverse my prior statements. However, this camp has helped me reflect on my position and refine my teachings, something I will continue to do until my time on earth comes to pass.

How I am thinking about fueling on rides currently looks like this: all cycling requires fuel, and the type, quantity and timing of the fuel depends on the type of riding you are doing, and the outcome goal you are working towards. Just like most everything in life, there is no “either/or” in the paradigm of fueling, it is a spectrum of choice and outcome. The spectrum is made of two polarities: on one end we have rides that are low intensity and on the other end of the spectrum, we have rides that are high intensity. The best way to explain this concept is using a bi-axial graph, which gives us four quadrants. On the X axis [horiztonal] we have rides which are low intensity [to the right side] and on the other end of the spectrum, we have rides that are high intensity [on the left side]. They Y axis [vertical] is made up of short duration rides at the top and long duration rides at the bottom.

High tech graphics by Me.

This gives us four quadrants which characterize our rides: long duration and high intensity would be the lower L quadrant, while short, low intensity rides will be the upper R, and so forth.

Here are the fueling rules: the more intense a ride is, the more carbs are needed for fuel during the ride, and as we get to the extreme end of the spectrum, the fuel needs to be straight up sugar. Specifically, a mix of different types of sugars, as a blend will help with gut absorption. Avoiding the use of only one type of sugar, specifically fructose but sometimes other sugars, is usually a good call as fueling with only one sugar can sometimes cause athletes gut problems.

The lower the intensity, the less carbohydrate we can get a away with, and the less sugary these carbs can and ought to be consumed, from my perspective. I will address why I am of this opinion below.

Rocket Fuel vs Diesel Fuel

If you want to run the engine with the throttle wide open, you have to put rocket fuel in the tank. This means sugar. When we say wide open, we are talking:

– Maximal effort intervals of any where from 8 seconds to 30 minutes, but in particular durations of 3-20 minutes or shorter bouts of repeated efforts

– Anaerobic Threshold / FTP / MLSS work

– “VO2” or efforts that bring you to the point of maximal oxygen consumption

– Anaerobic or glycolytic intervals

– Hard group rides with race simulations, pace lines, or maximal effort climbs

– All racing including time trials, criteriums, road races, hill climbs, etc.

These events or efforts are on the  L side of our spectrum. As the duration increase, the need for carbohydrates is simply calculated in grams / hour, and the number of hours is multiplied by the grams per hour to get the total amount of carbs required for an athlete. More on formulas and why they don’t work, below.

All of these events use a significant contribution of energy from the glycolytic energy system and this system burns glucose as fuel. This simplest, fastest and most effective way to get glucose in your blood stream so it can get to your muscles is by consuming sugars. Sugar = rocket fuel. Specifically, the rocket fuel that is currently all the rage is glucose – fructose blend at a ratio of 2:1.

Rocket fuel is made of up both “sports” foods and not “sports” foods:

  • gels
  • mix [that contains simple sugars and possibly complex carbs, but not protein]
  • candy that is mostly or all sugar like gummy bears, Swedish fish, etc

If you want steady performance on the bike, at sub maximal intensities [below FTP or MLSS or anaerobic threshold] then you may consider fueling with more “diesel fuel” as opposed to rocket fuel. There are advantages to using this type of strategy, and this is why it is important to distinguish between the types of riding you will be doing and what type of fuel you will use.

“Diesel fuel” can be ride fuels that have complex carbohydrates and also other macronutrients [fats and proteins] as well as fiber. The lower the carb content the more “Diesel” they become. Examples:

  • fruit and nut bars
  • protein bars
  • peanut butter and avocado sandwich
  • hot dogs [ask JV about the time he ate a hot dog in the middle of a ride to see the General Sherman Giant Sequoia with me for a good story]
  • beef jerky
  • bananas or other fruits such as figs

These are all examples of foods that would have more diesel characteristics than rocket fuel characteristics, and these types of fuels would be better for rides on the R side of our intensity spectrum, and towards the bottom [longer duration]. For shorter rides that are light intensity [upper R quadrant] we don’t normally need fueling [this is context dependent, sometimes a rider can be training very hard and need a bit of food even for a recovery ride].

A note on bananas: these are considered by some to be “nature’s energy bar” and Rigo rode to a podium at the Tour eating about a dozen bananas a day. That said, this quantity of fruit sugar or fiber may not work some athletes. However, bananas might work better than many other fruits.

You can also select foods that are what we might call “middle of the road” foods that split the difference. These might include:

  • rice cakes
  • rice balls with egg, prosciutto, etc
  • waffles
  • granola bars
  • any type of high carb processed food bar [like an old school Power Bar]

In planning your ride nutritional needs, you can select foods that have a higher fat and micronutrient content in order to offset the simple sugars you consume during higher intensity days on the bike. Rocket fuel gets the job done when you want to ride as fast as possible, but these are also empty calorie convenience foods, and this is one big reason why I don’t recommend riders train with gels on days when they are not doing maximal efforts.

If you are headed out for a 3 x 15 workout at maximal pace, some mix in your bottles and some gels in your pockets may serve you really well. If you are not fueled for this intense work, it may not just make the work harder, it may make it impossible for you to hit the prescribed intensity.

However if you are riding for two hours at steady aerobic endurance pace, or doing a 160km long road ride which will be mostly low intensity and have a long coffee stop, it may make sense to use only a bit of mix and some foods that are more middle of the road or straight up diesel, depending on what your ride goals are.

For rides that will be of mixed intensity, consider a split approach to your nutrition: some mix, maybe a gel or two, and some middle of the road foods.

Manipulation of macronutrients can influence fuel usage during a ride: consume more fats, burn more fats. Consume more carbs: burn more carbs. Thus, if you want to up-regulate your fat metabolism and carbohydrate sparing on the bike, consuming a low carb breakfast with a higher fat content will help with this objective.

Likewise, if you want to perform at a competitive level in events that require high output, training on your interval days with the same fuel you will use for your races will enable you to know how your body responds to these fuels, as well as train the enzymes necessary to utilize high quantities of sugar in the muscles. Both of these aspects are necessary for optimal performance on race day.

That said, any rider who wants to perform over long events such as road races or gravel races needs a balance of fuel sources available to generate energy. This means each of these “energy pathways” must be trained at some point. If a rider simply consumes sugar and goes hard all the time, eventually they may compromise their ability to burn fat at lower or medium intensities of riding, which is a fundamental component of cycling. It’s easy to watch the Tour and see the finale on the big climb and equate the winning rider as the one with the highest threshold power [or w/kg if you are thinking a bit more] but that performance was built on weeks and months of training at lower intensities that were fueled by fat, specifically to spare the rocket fuel for that final, magic 22 minutes of maximal effort that makes such electric television.

Likewise, if a rider goes full keto for months and the shows up to a criterium, it is very likely they won’t quite have the glycolytic engine or lactate buffering to perform at their best. We have to fuel for and be trained for our event.

Takeaway: there are dogmatic people on both sides of this fat vs. sugar spectrum who are convinced their way is the only way and who will fight you to the death with a pile of science and anecdote. That is real neat but the truth is, extreme behaviors in sport [or anytime in life] result in extreme consequences and when the pendulum swings too far out of balance, it eventually swings back. This is natural law. Sports people are often guilty of “if some is good more is better” mindset. I am not here to tell you what to do but I do know what happens when extremes are chosen over long time periods. If you are thinking “yeah but not me” or “I can get away with it” or “I have to because I am not that talented”, feel into your expression of the Hero or Victim archetypes for a minute and then come back to center.

Ultimately, everyone is an N of 1, which means you will have to experiment and find out what fuels work for you. One rider’s rocket fuel can be another’s kryptonite. It is definitely optimal to avoid kryptonite on race day.

About 15 years ago, 50-70 g/hr of carbohydrate was considered the standard; today riders are commonly targeting 90g/ hr, with some riders pushing the envelope of extremes:

See the note above on N of 1 in regards to how many grams per hour of sugar you can ingest on hard rides. The trend seems to be; if the gut can handle it, the more you put in the faster the rider will go.

One point that can be confusing is the topic of insulin response to sugar intake. Our moms told us not to eat too much sugar for good reasons: it is horrible for your teeth and also will cause an insulin response, as the body works to regain homeostasis in the levels of sugar in the bloodstream. Repeated swings in insulin and blood sugar are associated with many health problems, not the least of which is weight gain. However, once an athlete is riding, the insulin response is severely reduced or completely eliminated, again based on where you are in the spectrum. When a rider is 3 hours into a hard ride, any sugar that comes into the blood stream will immediately be burned for fuel. This means the blood sugar levels won’t rise high enough to generate an insulin response, which is the cause of the “crash”. The old saying is “When the furnace is running really hot you can throw almost anything in.”

Listeners of my podcast will also understand I am very cautious to recommend formulas for anything. This is in part because I have tried to apply formulas many times in my racing and found them to give me unsatisfactory results. So, while you might be temped to start adding up the grams of carbs and to glue yourself to a formula, this choice might simply invite a deeper level of understanding through some unpleasant experiences. The way I think about it is: formula is a starting point for learning but following it dogmatically or without critical thinking will be self-defeating. A formula must always be utilized in context.

As an example, if you start a road race in 40 deg F weather with light rain, your fueling needs will be completely different than if you start the same race in 94 deg F, sun, and 90% humidity.

In my experience, there are several factors that can influence the response to caloric intake:





Acute caloric load

Phenotype of the rider: glycolytic vs aerobic

The last one on this list is not trivial: the dominant muscle fiber type of the athlete will influence the fuel utilization and requirements during rides. To illustrate this point, consider an example two riders of identical weight and CdA; however one is a classic “sprinter” and the other a “time trialist”. The later will certainly have a higher percentage of slow twitch fibers in their muscles which will run more effectively off a higher fat percentage than his sprinter riding companion. For the same average power and the same number of KJ’s of work, the sprinter will burn and require more carbohydrate than the time trialist. This is because even with the same thresholds, at any given intensity the sprinter will be using more glycolytic energy than the time trialist, and thus require more carbohydrates to ride at the same pace.

Thanks for reading.

Pedal fast, pedal consciously, pedal smooth.