TGIF Newsletter (21st April 2023) - Commentary

TGIF Newsletter (21st April 2023) :

Contents :

  1. Watts per Kilo Discussion : Lanterne Rouge with NERO Show
  2. How to Carb Up
  3. Absolutely Savage (SAFA Brian video)

Reader Commentary :

The "How to Carb Up" section contains a video by Cam Nicholls who took on an extraordinary amount of carbohydrates prior to a race. The video was relatively simple and lacked some nuance.

A reader of the newsletter reached out to me and offered some additional commentary about the video. It's really interesting and i've published it below for you (lightly edited for clarity) :

Hi Yuva,

I had seen the Cam Nichols video already. I’m kind of surprised that the amount of carbs required seemed unusual for him. I would have thought a serious rider (like I think he surely is) would well understand the sports science.

Many studies have shown that a 2:1 glucose to fructose ratio is the best way to get fueled for elite athletes. Curiously, his video never actually talks about the glucose : fructose ratio, or about why there is a ratio for that matter (60g:30g per hour), nor did it harp much on the reason or importance of the two specific sugars, if at all.

I can’t remember, but I think not. He only talks in general about carbs. That’s not really so helpful. Broccoli is carb, as is the banana he ate for breakfast, but it matters more what carbs, i.e. what sugars. Of course, you need a good breakfast in his circumstance, so I think he accomplished that, and preloading even a few days before an event with carbs is kind of standard.

The issue in the exercise science was about specific performance hindrances, and with elite athletes having gastro distress during an event. There developed an understanding of how the body transports fuel into the bloodstream; the known limit regarding glucose transport per hour of max levels befitting elite athletes, turned out to be 60g/hr. That this was insufficient fuel to sustain the elite performance effort, to “extend” it before exhaustion, before crashing. Also, crucially, it had become clear that the type sugar (the type of carb) matters; glucose is the most efficient and quickest to the uptake. 

But it’s also now well established that fructose has to be added to get around the body’s inability to transport more than 60g glucose per hr to the bloodstream. Fructose is the way to get more fuel bc it’s transported via a different pathway, thus it complements the full 60g glucose; doesn’t cut into the total glucose being transported. The 2:1 ratio glucose:fructose is solidly supported. 

Even super athletes cannot get more than 60g glucose into the blood per hr. And less than super athletes likely don’t need 60/hr. In either case, if you put more than 60 in your gut, only 60 is used, and the remainder can be detrimental bc of stomach distress from overloading while undergoing peak level of exertion. Perhaps, I’m hashing over stuff you already know, in which case, apologies. I’m just an old guy on a bike, but electrolytes and energy for rides makes a difference still. So, I’ve done the research a bit. I’m curious why Cam found this breathtaking stuff. 

I actually just posted about how to make a good electrolyte drink and energy drink on my little YouTube channel yesterday. I wrote some notes about this stuff and appended it to a spreadsheet i set up for the formulae. If you’d like to waste 20 mins of your life you can look up The Unabiker channel. 

Link to Unabiker Channel.

The other point I took from his presentation was that eating the buffet of all the different carbs prior to the race may not have been the best tack. I don’t think it hurt, but again, the type of sugars matters. Honey and banana and muesli and whatnot is a mix of stuff, kind of undirected carb buffet. Certainly, it’s all turned into sugars once it’s ingested, digested, metabolized, but it’s not efficient.

I’m no expert, but my understanding of how the sugar transport pathways make a difference, and my Chefly general knowledge of nutritional good sense leads me to think you need a good meal to get started on the day of course, and you don’t want to feel hungry, but anything more than 90g of these two sugars, 60g of glucose : 30g fructose, will not actually hit the bloodstream. And since the menu was a carb buffet, it’s hard to say what amounts of which sugars was ingested. I don’t think it was harmful, just maybe interesting. 

I think elite athletes have doctors and nutritionists guiding their performance needs, and making sure they’re getting loads of electrolytes, plus the 90g total of the correct carbs at the proper ratios. Doesn’t matter if you are Ganna or Vingegaard. They’re both powering away at peak levels, but face the same limits of how much fuel they can transport to bloodstream per hr. That limit is 1g glucose per minute, 60g/hr. For fructose, that limit has been subject of lots of study. It’s varied from study to study, some have proposed the ratio isn’t 2:1, but 1 : .8. In which case that’s 60g glucose to 48g fructose, 18g more of the right sugars (20% more), but my understanding is that the 2:1 ratio has become the consensus. Ganna and Vingegaard are no doubt ingesting the max sugars, not more. Both the same despite body size discrepancy. What their bodies does with that fuel is what’s different. I find that pretty interesting. 

Now, I’m sure athletes maybe test these limits, and this is why some suffer gastro intestinal discomforts. If Ganna ingests more than the 60g glucose per hr, thinking he’s that much bigger than Vingegaard, and needs more, it actually has no beneficial effect, bc the transport mechanism to get it into the bloodstream can’t do it, but it might make his gastro system feel not so great. This is a known problem with fueling during this level of exertion. 

I’m sure Cam’s nutritionist knows the science, and nothing he ate prior to racing (what was it?…250g total carbs I think) was going to bog him down. I can’t recall precisely, but I think he mentioned he had 90 minutes between wake up and race start time. So 250g carbs probably isn’t a problem, and I didn’t find his breakfast really huge. In any case, his video did note a in race fueling level of 90g of carbs per hr during the ride, so it’s all good, but neither is it breathtaking news. It’s simply the accepted, and well-established guideline.

There’s a really good website for a UK company that makes energy supplement products for this level of athletic exertion, and it discusses very clearly the science, and also has some good embedded video’s to help illustrate various points. It’s not simply marketing their goods. It’s really solid info.

Here’s the spreadsheet I mentioned (GOOGLE DRIVE LINK TO DOWNLOAD, FORMATTED IN APPLE NUMBERS). There’s a link to the company in it. 

Kind regards,


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