Carbohydrates

Daily Nutrition

In the Swing of Carbohydrates Part 2


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In part 1, I discussed on how a low-carbohydrate diet seems to be healthier. But remember that there are no real definition of what is a low carbohydrate diet. For me,  based on the research paper that I’ve read, RDA levels and our paleo ancestors, I would put the threshold  below 35% or for a 2000 kcal diet, that is about 175g of carbs per day. To be honest I’m not even there and my diet usually fluctuates between 80g and 160g. The majority of my carbohydrate intake comes from fruits (2 servings per day) and dairy, while potatoes and rice and whole grains, I eat more rarely, mostly when my training is either high intensity or longer. Oh, and I forgot to mention wine and dark chocolate…Am I suppose to tell you that?

But what about performance? We all know that carbs are necessary to perform well, especially at high intensity. Carbohydrates in the form of glycogen is our reserve for when the lion attacks and we need to run fast! So when we are out of glycogen and our blood sugar drops, we fatigue. Carbohydrate are so wonderful that when we swish a carbohydrate solution in our mouth, it has been shown to improve performance, even for 1 hour events when carbohydrates are not really needed. On the other end, other studies have also shown that training with low glycogen or carbohydrates on board activates mitochondrial gene expression, which in turns will improve training adaptation.

Recommendations for performance

Currently the recommendations for optimal performance stands at 8-10g/kg daily of carbohydrates. If you do the math, taking me as an example, that would be 560g or 2240 kcal of carbs. Basically on a day where I exercise for 1.5 hour at moderate intensity that is my whole calorie intake for the day! Ten bagels, here you go. OK, I’m being a little bit facetious but if you look deeper into the litterature, these recommendations are  for athletes who actually spend a lot more energy per day such as Tour de France cyclist or someone who exercises 5+ hours per day. I would probably fall in the 6 g/kg/day or  350g carbohydrate per day with my 1.5 hour of exercise. That is still a lot and I consume less as mentioned earlier. These recommendations stems from research that is not wrong in essence but we need to look at how it is done. First of all these studies are done with athletes that use carbs as their main fuel, they are not adapted to a lower carb, higher fat diet and if they are, it is not for a long time. Even if you adapt for 5-6 days you don’t get the full benefits of athletes who have been going at it for a long time, as you will see below. So basically what the researchers do is that they take an athlete, have them exercise for however long and then measure glycogen after the exercise bout. Then they look at how much carbohydrates are needed to reestablished normal levels. The thing is if you don’t use as much glycogen because your metabolism oxidizes a lot of fat instead of carbs then you’ll need less to reestablish current levels. Does that make sense? In essence they are not wrong, you will need that amount of carbs if you are a high carb burner, but if you burn more fat probably not.

Actually the research is starting to take off in the low carb high fat department. Let’s look at the preliminary results of the FASTER study. They looked at two different elite athlete cohorts participating in ultra-marathons. One was on a high carb diet (60%) and the other one was at 10-12% in carbohydrate. If you look at the difference in fat oxidation between the two cohorts, it is huge! The HFD oxidized 50% more fat than the high carb. How long did it take them to get there? You have to have mitochondrial adaptation, higher intramuscular triglyceride (fat) storage, changes that do not happen overnight even if your fat oxidation per se can increase very quickly because of a change in your diet.

fat_adaptation-5-240x180

Now let’s look at what are the requirements during races. It is on average 1g/min of carbohydrate or 40-60g/hour. It is not reported per kg because the limiting factor is our gut, above that level carbs do not get absorbed very well. However, you can train your gut to absorb more carbohydrates to a certain extent. This is definitely too high for me and on average during triathlon and other events I’ll have about 20g/hour of carbohydrate with some proteins and fats for longer events.

And then for recovery the suggestion is 0.8 to 1.2 g/kg with some proteins, the sooner the better, within 30 min. to 2 hours.  Again this seems a lot to me for a 90 minute session of exercise. But as sessions get longer and harder this is not a bad place to be if you can add at least the same amount of protein in there.

And how am I doing?
 

And now that I’ve shared with you how I use carbohydrates compared to the requirements, how is my performance in all of this?

Since using this strategy, my times have been improving. Last year I had a 20 minute PR at the half-Ironman race and another PR at an Olympic triathlon. I just felt great the whole time in both races, very even energy. I also don’t bonk during long training rides anymore and do not feel nauseated on the run. And I don’t need to eat as much! It is not that I perform necessarily better, I don’t think I would score better on a TT on the bike or a 10K,  but for longer events I can perform to my optimum the whole time, that is what makes the difference. Here is a breakdown of my calorie intake.

For the Half-Ironman:

On the bike every 30 minutes: 1/4 of Bonk Breaker protein
at 1.5 hours on bike: 2 scoops of UCAN*, sipped for 20 minutes
at 2 hours on bike: 1 shot of espresso, 80 mg caffeine
at the beginning of run: 2 scoops of UCAN
1 hour into run: 1 shot of espresso with caffeine (See my blog on caffeine!)

*If you are not familiar with UCAN, it is this slow release corn starch that enables to maintain steady blood sugar.

Total calories: 630=114 kcal/hr
Total carbs: 121g carbs=22g/hour

For my last Olympic, I just had a packet of UCAN for the whole time, and that is it simple: 132 kcal, and 13g/carb per hour. Of course in all those strategies I make sure that my reserves of glycogen are full by having appropriate meals the day before and a breakfast or snack before the race. Again I’ll use UCAN in a shake with 5g protein and some fats an hour before the race starts. In comparison I used to have 30g/hour of maltodextrin and other sugars and would totally bonk on the run. Maybe if I could have ingested more carbs I would have done better but I just could not stomach it.

So what is the difference between now and then is that I am now more metabolically efficient! Of course I did not go at it by myself and got the help of Dina at eNRG Performance. In my next blog, I will talk about testings you can do to know how metabolically efficient you are.

Talk to you soon!

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Daily Nutrition

In the Swing of Carbohydrates


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Two years ago, I went to the doctor to get the results from a blood test called the HbA1c. It is a test that measures the amount of sugar on your hemoglobin (on your red blood cells) and apparently correlates very well to your average blood sugar over the past 3 months. Then, just out of the blue the doctor tells me: you are pre-diabetic. It seemed surreal. Me? I exercise a lot, healthy eating, no weight to lose (maybe a couple of pounds, but there will always be a couple of pounds). My HbA1C, was at 5.9, pre-diabetes starts at 5.7 and diabetics at 6.4.
First of all diabetes means that your blood sugar levels are higher than average. There are two types. Type 1 is when your pancreas does not produce enough insulin due to genetic defect or other causes. Insulin is a hormone which acts on cells to absorb glucose, in particular muscle cells and liver cells where glucose is synthesized into glycogen (a long sugar chain, similar to starch) or fat cells where it is converted to you guessed it: fat. Insulin has also multiple other roles, which I won’t cover in here. Is insulin really bad for you? Not really, it is not the insulin the problem, it is the overload of sugar. High sugar, the body secretes insulin, cells absorb, absorb and sometimes a bit too much which results in hypoglycemia. Now you are feeling weird, hungry, dizzy and well, reach for another snack which increases your blood sugar again. Welcome to the sugar roller coaster. If you are pre-diabetic or Type II diabetic, this roller coaster is like the Matterhorn. Your insulin does not control very well the process, just like a poorly tuned thermostat which never reaches a set-point but goes way up in temperature and way down before it kicks in again. Some people might be better at regulating this whole process depending on your genes and lifestyle.
Here is a graph that I found at Suppversity. It helps explain where we, humans are coming from compared to where we are at now. It shows the average percentage of carbohydrates in the diet (minimum and maximum) compared to the latitude our paleolithic ancestors were living at.
As you can see some of our ancestors living in the North did not have any carbohydrates during the cold months of the year. While people living in warmer climate had up to 34% of carbohydrates in good times. What is the RDA recommendation these days: 45-65%! And some of us eat up to up to 70% of their diet in carbs. That is a lot compared to what we were technically supposed to handle. No wonder our thermostat is out of whack. Of course if you are very active, you can probably handle more without significant effect, but when I say very active, I mean it. Our ancestors where already pretty active so if you think that you move more than a hunter gatherer, well go ahead.
So what should we do? Low-carb, Ketosis diet, Paleo diet or a mix of these? These are the new cool diets out there. You don’t know what these are? To tell you the truth, I would ask different specialists, I would get different answers but bottom line, the idea behind these is to get closer to what our body is able to handle without negative effect on our health. I would define low-carb diet as having less than 35% of your calories from carbohydrates. From a 2000 calorie diet that is less than 175 g or the equivalent of 5 apples. The ketosis diet is when you go below 50g, at that point your body starts making ketone bodies for your brain because of the lack of sugar, but don’t worry it is not dangerous and can be actually beneficial. The paleo diet uses only ingredients that could be found from hunting and gathering. This diet can be higher in carbs but because of the restrictive carb choices, it tends to be around 35% too.  There is a super interesting article in the National Geographic on paleolithic diets. It turns out that eating paleo is not just about eating more meat. In fact our ancestors did not have access to meat half of the time. I think this is important to point out as some people take the paleolithic diet to extreme and eat too much meat. Although as you will see below, meat and saturated fat in meats are not as evil as we thought. However, other sources of protein should be considered such as in fish, seafood and plant protein and present a much sustainable way of living for the future generation. So what else did our paleo ancestors eat? They had to rely on plants, tubers and nuts found in nature. And yes, these are carbs, but they are non-processed and it turns out that carbs’ density (g of carb/g of total food) is actually low. So on some days they might have eaten a lot of carbs, other days mostly meat and the rest of the time mostly fat depending on availability, but when you run the number you get what you see in the graph above.
Are these new diets here to stay. I would say YES! More and more studies are pointing towards the benefit of a low-carb diet. Even the New York Time lately had an article on low carb diets. The article starts like this: People who avoid carbohydrates and eat more fat, even saturated fat, lose more body fat and have fewer cardiovascular risks than people who follow the low-fat diet that health authorities have favored for decades. This study actually confirms the result of other studies. This meta-analysis, meaning that it summarized and analyzed the results of multiple studies on low-carb diets, concludes that diets that are lower than <35% carbohydrate, keeping the caloric content the same to higher carb group, had participant lose more weight and increased lean body mass (that also throws away the theory of one calorie is a calorie but that is the subject of another blog).
Mind you these all point out to the health benefit of a low-carb diet but what about performance? That is a different ball game…My next blog will definitely address this conundrum. I will share with you more about my experience with going low-carb. Am I still pre-diabetics??? How does that affect training and racing? You’ll see…