Automimmune Genes

This is an interesting article about how old the genes are that play a role in Crohn’s and psoriasis.

“Both diseases are autoimmune disorders, and one can imagine that in a pathogen-rich environment, a highly active immune system may actually be a good thing even if it increases the chances of an auto-immune response.”
The question they don’t ask, and we’ll never know, is if these ancient ancestors suffered from the symptoms of these issues. Then you could ask the question, like in the book “The Epidemic of Absence”, would people who suffer from Crohn’s today, benefit from from being exposed to pathogens?

The New Yorker on Gluten

This is a really good read. A bit lengthy, but the writer interviewed a slew of people from different sides of the “gluten debate.” I had a couple thoughts while reading this which I’ll expand on here.

The author writes about a study where the scientists concluded that gluten was the cause of a small groups’ IBS. Gluten was introduced in a double blind study and the gluten eaters had more IBS than the gluten-free eaters. The conclusion was pretty easy to make since it was the only variable they were looking for.  A separate study removed gluten and FODMAPs (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols); things like onions, garlic, apples, etc. Gluten was then reintroduced to the FODMAP group and people didn’t have the IBS issues they started with, so the conclusion was made that it was the FODMAPs and not the gluten that caused the IBS issues.

I think removing gluten is easier than removing all the foods that fall into the FODMAP category. If people feel better removing one item, they may not bother trying to figure out the FODMAP rules, especially when different sources list different foods for FODMAPs. It’s possible the FODMAP diet helps fix the underlying problem and allows people to eat gluten without issue, but there isn’t much sciene to back that up definitively. Going gluten-free may just a placebo effect and people just believe they feel better because they are “gluten-free,” but I think the first study shows some people feel the effects of gluten even when they don’t know it’s there.  I do hope that people aren’t just substituting everything with a gluten-free version because gluten-free cake is still cake and full of all kinds of other junk.

The other thing I thought about was how FODMAPs effect gut bacteria. The point of being on a FODMAP diet is usually to reduce the overgrowth of “bad” bacteria in the gut. When someone’s bacteria ratio is out of order, eating FODMAP foods may increase the bad bacteria, causing gas, bloating and other IBS symptoms. It is a possibility that the people in the study experiencing IBS were not gluten intolerant but had a poor ratio of “good” to “bad” bacteria in the gut and the FODMAP test helped fix this balance, so when the gluten was reintroduced to the FODMAP study patients, their bacteria were in balance and they didn’t suffer any distress. If they were not gluten intolerant, fixing the bacteria solves the problem. Whereas the gluten free test, where gluten was the only variable, the gut bacteria ratio wasn’t remedied but still provided adequate relief when gluten was removed. The question becomes, is gluten the problem, or is our gut bacteria the problem? And if it is the gluten, is it dose dependent, and  the real problem is all the extra wheat gluten producers put in bread to make it airy and fluffy?

While I personally feel better when I leave gluten out of my diet, and I take a probiotic supplement and eat a fair amount of prebiotic foods, I do tend to think that the nations dramatic increase in “gluten-sensitivity” (celiac or otherwise) has a lot to do with the bacteria we are inadvertently promoting by eating lots of boxed, processed, pasteurized and sanitized foods. We have very different microbiomes inside us than our ancestors did.

If you don’t believe gluten is a problem, and you think your bacteria is just fine, I’d encourage you to think about making your own bread. The stuff used to clean and bleach flour in processed breads these days is provocative at best and detrimental at worst. How much benzolye peroxide is left in the bread you eat from the store is hard to figure out, but if you make your own bread at home, you know there’s none.

Nutrition Nightmare – Traveling healthy

Our Latest installment in Miles and Minutes. PDF link here

Nutrition Nightmare

By Paula Inserra and Wesley Smith

So, you’ve decided to branch out and sign up for an out-of-town race. What could be better than traveling to some exotic place AND running? Your hopes are high! You picked a flat, fast course. Your training was spot on. You’ve endured set-backs, sure, but you’ve pushed through the nagging injuries. You’ve put in the hard work and hammered out a ton of miles in preparation for race day. You’ve done well staying hydrated on runs and your recovery drinks, well, let’s just say they were magical! You’ve eaten right; enough calories, but not too much. High carbohydrates, check. Moderate protein, check. And low fat. You’re fit, your muscles are strong and your glycogen stores are topped off! You are ready!

Then, three days before the big race you pack your bags and head out to the airport. Going through security; “better toss my water bottle”. Uh oh, flight delayed. “I better get something to eat. Hmm, only fast food here. What, $6.25 for a liter of water?! Maybe I should just wait until I get on the plane?” Then the flight attendant hands you a measly 14 pretzels and 6oz of water. “Well this isn’t going to cut it; I’m running a MARATHON in a few days! I guess I’ll just make up for it when I get to the hotel.” You arrive. Your running buddy is dying to try this Italian restaurant he’s heard about. You think, GREAT, finally I’ll get some good carbs. You both order the specialty, lasagna; and I guess one glass of wine can’t hurt, right? Here comes the meal, wait…I thought it came with marinara sauce? This is alfredo!Panic sets in when the waiter explains that they are out of marinara and to make up for it the manager is giving you a BOTTLE of wine on the house….

Does this sound familiar? All of your months of preparation can be jeopardized in a few short days. So what’s a nomad runner to do?

Prepare. Pack healthy snacks and an empty water bottle you can easily refill at water fountains. Search restaurants and come up with healthy options to order in advance. Hit a grocery store when you arrive at your destination to stock up on sports drinks, snacks and to pick up your tried and true pre-race breakfast foods. Don’t leave anything to chance. Most hotel rooms have refrigerators or at the very least an ice-machine. If your room includes a free breakfast, find out what is offered when you check in and if they will be serving early enough for you to make it to the porta-potty before the gun goes off. It’s also always a good idea to have your own foods ready to go. You can always take advantage of the hotel breakfast for the non-necessities like plates, utensils, toaster and condiments; this way you can avoid any extra pre-race anxiety in the event they do run out of bagels and bananas…

Here some power packed options for the nomad runner:

Shopping list (no refrigeration needed)

Fruit: bananas, apples, oranges, raisins, etc.

Bagels, breads, crackers


To-go peanut butter or chocolate hazelnut spread

Salty pretzels


Sports drinks

Bottled water

Juice boxes

Shelf-stable chocolate milk or soy milk


Restaurant Options

Sushi: It’s low in fat, high in carbs and has moderate lean protein. Just make sure it’s fresh and from a reputable place. Add an extra bowl of rice and some miso soup for added carbs and sodium.

Mediterranean: Hummus, pita, rice, grilled skewered meat or chicken, tabouli; great sources of carbs and low in fat.

Italian: Avoid lasagna, ravioli, stuffed shells etc. Stick with plain pasta with a small amount of marinara or other red sauce. Consider non-cream based seafood sauces for all the carbs plus some natural sea salt. Add some bread on the side for an added punch, but skip the butter or olive oil.

American/Pub: Keep it simple. Order some plain grilled fish or chicken, baked potato, small salad or veggie. Add some bread or rolls and avoid sauces, mashed or fried potatoes.

Asian: Simple stir fry with extra rice and soup. Avoid tempura or other fried options to keep it low in fat but max out the sodium with a nice dose of regular soy sauce.


Paula Inserra, PhD, RD, is an associate professor at Virginia State University, where she heads the Didactic Program in Dietetics. She holds a doctorate in nutrition science from the University of Arizona.

Wesley Smith, BS, is completing a post-baccalaureate certificate program in nutrition and dietetics at VSU.

NUSI Re-Writing “Eat This, Not That” With a New Study

A study, to definitively show that it’s the kind and quality of calories and not necessarily the quantity that’s making America obese, is now underway! This will hopefully redefine what foods we should and shouldn’t be eating and why. All of our “common knowledge” about what’s healthy may be based on misinformed assumptions and jumping to conclusions.

“One key study could be the hammer that dislodges the loose brick in the prevailing paradigm.” Hopefully this is that study.

Cha Cha Cha Chia….

Another article for the Miles and Minutes Richmond running magazine!


Cha Cha Cha Chia…

2012111915400853324_lrgWhat do nutrition, barefoot running and goofy Christmas presents have in common? The Tarahumara; a Native American people of northwest Mexico, described in McDougall’s national bestseller, “Born to Run”.  Tarahumara, literally means “runners on foot” or “those who run fast.” These are the guys who run long distances through rugged terrain, barefoot! Turns out, they also eat chia seeds. Other Central American natives called the chia seed “Indian running food” and warriors would use them as fuel in battle. And yes, it’s the same “cha cha cha chia” that sprouted magical fur in the mid-80’s on those clay figurines.


Chia seeds are now in everything from unique tea blends to energy bars. For health and running performance, chia seeds offer fiber, numerous minerals and healthy omega-3 fats, which is all the rage these days. While being a good source of plant protein, chia seeds also contain loads of calcium and are gluten-free, if you’re into that sort of thing. Although you probably tossed that Christmas present long ago, along with the stale fruit cake from Aunt Mabel, we may have you rethinking at least one of those decisions.


Let’s start off with what the chia seed is, and then we’ll move into what it is not. Chia seeds come from an annual herb, similar to mint, which is native to parts of Central America.  The word chia comes from the Aztec word chian meaning “oily”. Since you can extract about 30% of its weight in oil, the name is appropriate. For the nutritional nerds out there, its oil is 55% omega-3 and 18% omega-6 which can help balance the ratio of omegas in your diet. The chia seed is very small at about 1mm and can absorb vast quantities of water; up to 12 times its weight, which can help you stay hydrated. It has good fats, is high in plant protein, fiber, and minerals, and it helps reduce blood sugar spikes; when mixed with water it creates a gel which slows the absorption of sugar into the blood. Remember that paste you spread on your chia pet? That’s actually nutritionally beneficial too.


You might have already heard about some of these benefits, but is there a downside to these seemingly magic seeds? Of course no food is perfect. Let’s dispel some myths around chia seeds. First, the omega-3 in chia seeds is plant based, like flax seed, which is less useful than the fatty fish omega-3’s. When chia seeds claim to have more omega-3’s than salmon, it’s true on a gram for gram comparison, but it’s quantity over quality. Fish omega-3’s are in a form that packs more of a punch, so much less is needed to give your body what it needs.


There’s another myth that says chia seeds will help you lose weight. The idea is that if you eat the seeds dry, they will absorb water in your stomach causing them to expand, making you feel full and hence, reduce your appetite. One study tested this hypothesis; for 12 weeks subjects added 2 oz of chia seeds per day to their diet, but this did not make any significant changes in body weight or health markers. While it may not be a weight loss magic pill, the protein is good, the carbs are slow to break down and the fats are healthy, making chia seeds an overall good choice and a welcome addition to a balanced diet. Caution should be taken when adding any new regiment to your diet, especially before a run or race. We suggest you try it out before race day just in case the added fiber, let’s say, makes you a less than desirable running partner….


What makes chia seeds unique, compared to other healthy foods is their ability to absorb water. Leave a teaspoon of chia seeds in half a cup of water for an hour or so and you’ll have something akin to pudding. The soluble fiber in the chia seeds forms a gel, which slows down the digestive process, giving you a more controlled release of carbohydrates and water. Eating this “pudding” after a run will help you rehydrated as your body breaks down the water logged chia seeds.  Putting a serving of chia seeds in your coconut water, or your homemade hydration drink (check last month’s article for recipes), can help you prevent dehydration and recover after a long run.


Figure-3-Agouti-miceEpigenetics: we are given the building blocks by our parents, but you can decide how to use them. Rearrange them by changing what you eat and how you exercise.

“…our genes are powerfully influenced by environment and lifestyle to produce the unique gene expression profile with which each of us lives.”


And a study on mice shows that the building blocks can be changed by your parents diet and lifestyle.

“…two groups of mice gave birth to sets of identical babies carrying the same genes.  The babies were raised the same way from birth. They should have looked alike but instead, they barely looked related. In the first group, the babies were overweight, prone to diabetes and cancer and covered in fur the color of rancid butter. The mice in the second group were beautiful: lean, healthy, brown. Same nature, same nurture, radically different outcomes. What was going on in there?

“The difference, it turned out, wasn’t due to the mice’s genetic code, nor was it due to the environment. It lay instead in a mechanism that was mediating between the two. A gene in the sickly yellow babies was making a disease-causing protein called Agouti, which also affects coat color. The brown babies had the same gene, but it wasn’t making much of anything. It had mostly stopped working. The brown babies’ mothers had eaten a special diet during pregnancy: one rich in folic acid, which floods the body with tiny four-atom configurations called methyl groups. These methyl groups had infiltrated the growing brown mouse embryos and latched onto the flawed gene, shutting it down.

Here’s a great summary with a host of other examples of epigenetics from things like how starvation and gastric bypass effects children and grandchildren of the discontented.

Nature vs. nurture? Now there’s a third option. Diet and the environment of the parents and possibly even grandparents. Thoughts or comments? Post them below.


Another article my professor and I wrote together. Take a look to see how to make your own sports hydration drink, similar to the popular Gatorade ® or Powerade ®. Now that’s it’s hot and humid again, you need to hydrate properly and appropriately.


To drink or not to drink, that is the question ….


By Paula Inserra and Wesley Smith


You might be thinking the answer to this question is easy, but we’re not talking about a Richmond microbrew at happy hour on Friday night; we mean a tall bottle of water during a long run. We’re sure you’ve heard it said time and time again, “Hydrate, Hydrate, Hydrate!” But did you know that this is a relatively recent recommendation? Up until around the 1950s runners wore cotton, short-shorts, tube socks and were actually told not to drink during a run.

Drinking water during a race was considered a sign of weakness. So, what changed? Research and the subsequent explosion of the sports drink industry.

Research showed that performance significantly decreased when individuals lost more than 2% of body weight during a run. This morphed into a recommendation to drink to prevent dehydration and 0% weight loss; that is, drink in the absence of thirst. You may have heard the newer adage, “If you’re thirsty, you’re already dehydrated.”

So, if you’ll excuse the pun, athletes took this message and ran with it. Water bottles, sports drinks, hydration belts, Camelbacks® and water stops every two miles of a race. The sports drink industry loved the fact that sports scientists were promoting their product! The result? We’ve overdone it.

Today the major running-related health problem known to have potentially deadly consequences is overhydrating. Drinking too much results in Exercise-Associated Hyponatremia (EAH) or low blood levels of sodium.

When we sweat during a run, we lose both water and electrolytes (mainly sodium) but we replace only the water. This is true even if we exclusively drink full-strength sports drinks (which few of us do) because sports drinks are low in sodium.

The American College of Sports Medicine (ACSM) recommends that long-distance runners (marathoners and ultra-marathoners) should consume sodium at a concentration of 0.5-0.7g/liter. Most commercially available sports drinks contain 0.2-0.4g/liter.

Certain factors increase the risk of EAH. They include duration of exercise (4 hours or more of running at a slow pace); being female; having low body weight; excessive drinking (more than 1.5 liters of fluid per hour); pre-exercise overhydration; use of NSAIDS and extreme environmental temperatures.

It has been estimated that 2-10% of marathoners experience EAH. EAH has some physiological basis, mainly a result of the kidneys not excreting excess water during exercise, but most cases are thought to be a result of drinking excessively.

Low sodium in the blood can occur by drinking water or other low sodium beverages at a volume that exceeds sweat rate or by drinking the optimal amount, but not replacing the lost sodium. Both situations result in a dilution of sodium in the blood. Staying optimally hydrated is a balancing act. The goal is to prevent dehydration and excessive sodium loss while avoiding overhydration.

The good news is this is easier to do than it seems. While it is useful to know your sweat rate so you can replace the exact amount of water lost, drinking to thirst comes pretty close (less than 1.0 liter per hour).

Adding a little extra sodium to your favorite sports drink can also help. One-quarter to one-eighth teaspoon of table salt added to a liter of sports drink will bump up the sodium content to meet the ACSM recommendations. Of note is that one of those little packets of salt you might find in restaurants contains about 300mg, which is enough to supplement a liter or a 32-ounce bottle of sports drink.

Sports drinks contain interesting colorings and other additives that won’t help performance. Yellow 5, red 40, blue 1, acesulfame-K, modified food starch, acacia gum, glycerol esters of wood rosins, sucralose and brominated vegetable oil (BVO; an industrial flame retardant!).

Since we generally don’t expect to burst into flames on a run, we’d just as soon avoid ingesting flame retardants. Plus, it’s so easy to mix up a batch of your own sports drink. Try this tasty home-made version to optimize your hydration.


Basic Recipe

1 liter of water

3⁄4 tsp sea salt

1⁄4 cup organic sugar or honey

Pinch of salt substitute


Sample Add-In’s

Minced ginger

Crushed mint leaves

Orange, lemon or lime slices

Sliced cucumber


Paula Inserra, PhD, RD, is an associate professor at Virginia State University, where she heads the Didactic Program in Dietetics. She holds a doctorate in nutrition science from the University of Arizona.


Wesley Smith, BS, is completing a post-baccalaureate certificate program in nutrition and dietetics at VSU.

Here’s a link to the Gdrive it’s hosted on, in case you want to pass it on, and I’ve attached a PDF copy. You can pick up a hard copy at local Richmond, VA running stores like Carytown Running , 3 Sports, or Finish Line for free.


Overhydration can be fatal- Miles and Minutes.

Whitewashed Report

coverMichele Simon’s wrote a report about the whitewashing of America, or brain washing with milk and other dairy products. Dairy has been promoted as one of “natures” best foods. I think the take away here is yet again to always read the ingredients. Yogurt has been touted as a great probiotic, and it can be, but most of the yogurts should actually be called dessert with the amount of added sugar often included. Knowing where your milk comes from can bring peace of mind and benefit the cows as well.

A few interesting points she focuses on are that half of the milk from dairy cows is consumed as flavored milk (think chocolate milk), with cereal or in a drink (like coffee). That’s a lot of milk just used to sweeten or wet dry foods. And 11 percent of all sugar goes into dairy products. America has a sweet tooth, and in order to promote “adequate calcium intake” we’ve been taught to eat desserts for breakfast and for snacks any time of the day. And you know something’s not quite right when chocolate milk is touted as “the perfect balance of vitamins, minerals, carbohydrates and protein- a combination that can’t be found in any other beverage.” There’s marketing, and then there’s lying. We’ve lost sight of the line between the two. Know your facts and get past the idea that milk is the only thing that will make bones strong.

Dairy itself doesn’t have to be demonized as you can find quality, unsweetened healthful dairy, but the extraneous sugar and additives aren’t helping solve any of the obesity, diabetes, or osteoporosis problems. Making your own cheese and yogurt from quality milk is easier than you might think.

Read her full blog post here: Whitewashed

Gluten Sensitivity- Is it all in your mind?

wheat10aA friend of mine sent me an article link about how gluten sensitivity may not exist. (Link to article) I like that my friends (and anyone else) can send me links that push my boundaries and point out things that are contradictory to what I or other like minded bloggers post about.

I thought I’d share my opinion after reading the article and associated links. This is the email I sent in reply:

“This does seem like pretty good science from what I could read about it, but there will always be limiting factors. Mainly time and money. Time is the constraint here because some different “experts” have shown* that gluten can stay in the system, and have lingering effects for as much as 6 months. So while the 2 week cleanse period is a good idea, having gluten first, second or third in the line up of diets might have made a difference.

I agree the brain plays a huge role, being that if someone eats gluten and does so knowingly, they could feel worse than if they didn’t know of an accidental exposure. As far as everyone doing that, or submitting to a “nocebo” effect of feeling bad because they thought they were going to feel bad is definitely subjective and hard to quantify. Since every person has different “pain tolerance” and idea of “GI disturbance.” I would think the stool samples would’ve helped verify a difference between gluten and non-gluten diets. But when they say there was no measureable difference, they don’t tell us what was measured, or define what a “normal stool” is. If they were comparing stool samples of these subjects to “normal people” (as in the general public) I’d argue most of those people don’t have “normal” stool.  In the end they say “consider this: no underlying cause for gluten intolerance has yet been discovered,” which brings me to the classic argument of “absence of proof isn’t proof of absence.” We may not have the right tests, or our tests may not be sensitive or accurate enough yet.

To play it safe, I’ll keep avoiding gluten because it makes me feel better. If that’s physical from a chemical disruption or damage, or from a brain to body creation, I still feel better, right? It’s a very interesting topic and a lot more research is needed. The easiest way to feel good, is to eat real food, know where your food came from, and to cook it yourself. Thanks for the link.”

A few thoughts came to me after I sent this email too. The study talks about what they limited, ie. gluten, FODMAPS, whey, but they didn’t talk about what they included. Was it organic microwave meals? Was it fresh veggies from the garden? Was it low quality ground beef cooked in hydrogenated oils? And they didn’t really say if the GI issues were alleviated during the 2 week “baseline” diet. So at the start, this looks like a good study, but there are still a lot of questions left unanswered, and the conclusion the media makes from it isn’t very strong. They try and make it seem like the general population that is buying gluten free products is wasteful. And lastly, I wonder where the funding came from to do this study. Is it “big-ag” trying to convince people that wheat/gluten intolerance is “all in their mind?” Probably not. Keep an open mind and eat what makes you feel good.


* – I use the word “shown” because, as evidence by the linked-to article, proof can be subsequently be proved differently.

The Skinny on Fat Loading

Here’s my second article for the Richmond, VA “Miles and Minutes” magazine. My professor and I co-wrote it. You get it here before it’s on the shelves! I’m not completely convinced that fat loading isn’t the way to go for endurance athletes, but this is what the science says at the moment. Hopefully we’ll get some more complete, longer term studies done in the future which will give us more insight. And without further ado…


The Skinny on Fat Loading

Have you noticed a growing number of articles and blog posts about “fat adapted” athletes? There’s one about Tim Olsen, an ultra-marathoner, who won the Western State 100 in 2012. Then there’s Ben Greenfield who finished the 2013 Ironman Triathlon World Championships in just under 10 hrs. More recently the LA Lakers were reported to be on a “Paleo” diet. All these athletes have one thing in common; they abandoned the time-tested method of “carb-loading” and replaced it with “fat-loading.” But before you start dreaming about reaching your ever-elusive PR by replacing your oatmeal and banana breakfast with one of bacon deep fried in butter, you might want to check out what the research actually shows.

Some studies report interesting findings regarding the exercise performance of subjects instructed to eat more fat in their diets. Participants improved their time in a walking test, and some cyclists’ endurance improved slightly in a timed event but these studies are riddled with serious limitations. Lower intensity exercise, like walking, depends less on glycogen stores and more on fat use. Furthermore, as a person adapts to training, fat usage improves, no matter what the diet consists of. In the study with the cyclists, some did do mildly better, while others did worse, but most had no change at all. The timed cycling event also bears little resemblance to real world situations, let alone racing.

Some sources will tell you it takes 2 weeks to become “fat adapted” while others state it could take as long as 3 months. Most of these “sources” seem to be simply repeating anecdotal information they read on a forum or blog. Unfortunately, there are simply no scientific studies that tell us how long it takes to become “fat adapted.” While it’s reasonable to think this diet might work after reading to some of the arguments, upon further evaluation it really isn’t all it’s hyped up to be.

The most pervasive argument compares glycogen vs. fat “fuel tanks.” Consider a 110 lbs. woman with 15% body fat. Roughly speaking, she has about 16.5 pounds of fat. Those 16.5 lbs. translate into almost 30,000 calories, or enough fuel for her to run almost 300 miles! On the other hand this same woman only has about 2,000 calories of stored carbohydrate i.e. glycogen, barely enough to make it through a 20 mile run. Armed with these facts, if you’re a long distance runner, it seems logical to tap into the larger fat fuel tank. Studies do show higher fat burning after eating a high-fat (65-70% of energy) diet. Unfortunately, it doesn’t translate into performance improvements. While the body begins to metabolize fat more efficiently, it loses the ability to use glycogen at a time when carbohydrate requirements are essential.

Generally speaking, endurance or ultra-endurance sports are regarded as a “slow burn” exercise; a sub-maximal aerobic exertion that doesn’t need to use glucose, justifying the researchers observations in the lab tests. However, the strategic activities that occur during races: the breakaway, the push through an uphill section, or the sprint to the finish, are high intensity exertions that require glucose. The evidence shows that this sprint ability in real world situations is actually hindered by “fat adaptation.”

So what if we combine fat and carb loading to get the best bang for our buck; a full tank of fat for the long open road, and glucose for the turbo when you need it? Studies have tested getting athletes to become “fat adapted” and subsequently carb load in hopes to achieve this hybrid performance boost.  But despite 5-6 days of increased fat consumption and then a day of carb loading, no clear performance benefits were observed.

The idea of fat adaptation is still being pursued; some say the studies were too short in duration and the subjects didn’t have enough time to fully “fat-adapt.” Until long-term studies are done, we won’t know for know for sure if athletes like Ben Greenfield and Tim Olsen are anomalies or if there’s any actual benefit. While we know there is some additional fat burning when someone eats more fat and low-carb, this is just because our bodies are smart enough to use available fuels, but it doesn’t mean it’s a better fuel for performance. Glucose is still the “hotter burning” fuel, so for a quick burst, like sprinting, running up a running up a hill, or passing in a race, carbs are the body’s preferred fuel. Furthermore when you’re coasting through miles 12-18 at marathon pace, fat is burned more efficiently when carbohydrate is also available. Consequently when we burn more fat, we don’t necessarily run faster and we actually lose the ability to shift into overdrive. If you’re gunning for that PR, train harder, enjoy your food and stick with what we know works for sure; a mixed fuel diet that’s high in carbohydrate.