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Re-United with My Sugar Addiction…..

Post-Holiday Addiction

I think we have all faced this at one time or another, you visit an amazing place with phenomenal food and you trying everything insite because, hey you’re on holiday.

Many of you will know I have just come back from Melbourne and to those that have been to Melbourne, you will know that is world renowned for amazing food. As a massive foodie, it is fair to say I went a little overboard…. But no regrets because that is what holidays are for, expanding your horizons to new things, just sometimes that also means expanding your waistline at the same time. There is nothing wrong with this and I think we should all live and experience life but I have noted since coming home the true danger lies in coming home reunited with my old friend my sugar addiction. As I have stated in many of my previous articles this is powerful as a cocaine addiction, as it reacts in the similar fashion in the brain.

In realising the trap for myself I quickly realised that I will not be alone in this struggle, so why not share the strategies I will implement to get myself back on track. This document is for anyone looking to cut sugar, it doesn’t matter if you have been on holiday or not, just coming out of winter can be hard enough, as we tend to drift towards comfort foods

Cold Turkey

Just like any addiction moderation is not a good idea as “just a little bit” ends up as a “big bit” or “another bit”

Time to be strict, no more sugar for me for at least two weeks, so goodbye to my beloved chocolate, although I eat 90% dark chocolate it does still have a small amount, so that will have to go as well.

Two weeks strict no leniency and following this I will reassess and most likely be more liberal with good quality sources eg my dark chocolate (90%). The key focus is to break the habits of snacking.

 

I’m going, Keto

Those who follow me know that I am an advocate for keto when done appropriately for the right person, I have written extensively on it

I traditionally cycle in and out of keto depending on my training and racing schedule, but it looks like it is time for another solid cycle of Keto, especially with race season around the corner now.

Keto is one of the quickest ways to kick the cravings to a curb. However, it is always harder going into with re-established sugar cravings. The induction period can be tough as for any detox you are removing an addictive stimulant that you currently rely on. Your body doesn’t know what hit it, naturally, you begin to crave those foods more and begin making elaborate explanations and justifications to why you “need sugar” or “This is a good source of sugar” All this does is draw out the induction period. If this sounds like you and something you have tried and failed with before, the next couple of steps may also be challenging for the same reasons but don’t worry we have a solution for you! Check out the Exogenous Ketone section.

There is no one fits all approach

Not everyone needs to go full keto, high fat low carbohydrate (HFLC) will be sufficient and keto maybe to extreme for many. You need to keep in mind my baseline of carbohydrate intake was previously very low and I know I personally function best in this state with my performance goals. Everyone will function off varying amounts of carbohydrate. It is what Cliff Harvey calls “carbohydrate appropriate” so don’t feel like you need to go all or nothing. I would personally suggest starting HFLC and see how you go, re-assess and decide if you want to take it a step further to keto.

 

No Snacking

While on holiday it is easy to snack and graze on food throughout the day. Although our bodies are not designed to graze, this places a greater demand on our digestive system which in turn our body neglects other key processors.

Back from holiday is a great time to establish my new routine so no more snacking instead focus on 2-3 key nourishing meals.

 

Intermittent Fasting

For those like me who like to take it a step further beyond restricting carbohydrate and snacking and want optimal benefits. Intermittent fasting should definitely be considered as it provides your digestive system a greater opportunity to rest placing less unneeded external stress on your system

There are wide-ranging fasting protocols, that you can select from and to learn more read my previous posts but I think the key to any of the protocols that is often missed is that you should never suffer! Fasting is not about starving yourself it is about listening to your body and eating when hungry. As you become less reliant on carbohydrate for fuel and your body shifts over to primarily utilising your fat stores, as this happens you will naturally be able to fast for longer, but you should never push this adaptation phase, listen to your body and gradually increase your fasted window.

 

This is too hard! I Need a Helping Hand

If you are struggling with the above steps and you need a helping hand or just want to stay feeling amazing, look no further than Exogenous ketones.

Exogenous Ketones

Cravings and hunger catch us all off guard at one point or another but what if you could remove these while putting yourself into a fat burning zone (ketosis) while increasing mental capacity and clarity.

Sound good?

Exogenous ketones are the answer with an extensive list of benefits they are phenomenal from a performance standpoint but also a sugar addicts best friend as they detox the sugar. They are my specialist trick and often refer to them as the “catalyst for ketosis”. There is nothing as powerful in getting you through the tough times of induction period of keto or kicking the sugar addiction. Firstly because they taste amazing (even sweet) but because they remove hunger, craving and keep you performing at your best. Plus they are high in electrolytes which keeps the dreadful keto flu at bay.  

 

Out of Site out of Mind

When struggling with willpower which you most likely will early on, hide your treats. For some, this is not enough so I suggest giving them away or throwing them out so that your house is clean with no treats.

Accountability

Get friends, family, flatmates onboard. Let them know your plan and why you are doing it, ask them to keep you honest and on track, because let’s be honest we can justify anything, at least this way you will get an unbiased accountability.

Brush your Teeth

Danger time for me is following dinner, normally when I reach for the dark chocolate or go for seconds and then thirds when I am not even hungry. Brushing your teeth straight after dinner is a great way to stop yourself from eating

Join in the Journey: Stay Tuned

Join me as I re-undergo this induction phase and ditch the sugar and carbohydrate. I have my exogenous ketones ready to go and looking forward to being addiction free and back full of energy with no spike or crashes.

 

Science Behind Ketone Supplements

Part Two: For those like me who enjoy the science

After discussing the application and benefits of exogenous ketones in my last post, I want to dive into some science behind them and highlight the differences between various types to arm you with the knowledge to make the right decision.

What Are Ketones?

Natural, Clean Energy

Ketones are our fourth fuel substrate, they are clean-burning as they reduce the production of potentially harmful Reactive Oxygen Species (ROS) inside cells. Plus they also clean up ROS produced from other metabolic processes.

Ketones have been shown to be preferable fuel for the brain over glucose as they aid in brain development. When ketones are present they preserve glucose for pentose phosphate pathway which results in ribose for DNA syntheses and NADPH for lipid biosynthesis

Before we touch on ketone supplements you must first understand the mechanism that defines the state of ketosis. Simply put, when your body is in a state of ketosis, ketone bodies are present in a higher concentration than normal (0.5+ mmol/L). I have discussed this further in the previous post

Three Ketone Bodies:

  • Acetate (Acetone): Is the least abundant, produced in much smaller amounts, and is usually exhaled through the lungs rather than being used as fuel.
  • Acetoacetate (AcAc): Is part of the metabolic pathway whereby humans make and use ketones, but it tends to be found in the blood at lower levels than BHB.
  • Beta-hydroxybutyrate (BHB) Is the most prevalent of the ketones. Due to far higher concentrations and existing outside the cell, compared to Acetone and Acetoacetate it is widely used to measure ketone levels.

Two Forms of BHB:                                                                

  • D-β-hydroxybutyrate: The right-handed version. 

“D” comes from the Latin dexter.

  • L-β-hydroxybutyrate: The left-handed version, lab-made ketones.                    

“L” comes from the Latin laevus.

D-BHB vs. L-BHB: Which is better?

There is currently a lot of controversy around which form is safest and best to use as a supplement form. One side argues the D-BHB is superior in enhancing mitochondrial function, whereas other evidence suggests a mixture of D & L is handled better and more beneficial for neurological diseases and cancer. L-BHB is thought to be a signaling molecule to reduce inflammation and has been shown to also convert a portion to D-BHB. Additionally, the production of D-β-hydroxybutyrate (right-handed) is a more expensive supplement to produce.

When measuring it may appear that D-BHB promotes higher blood ketone levels. However, that is because most commercial ketone measuring devices only measure D-BHB, not L-BHB.

To the best of my knowledge, there has not been a comprehensive study to truly determine if D-βHB is more beneficial than DL regarding general use applications, or value to the consumer from a financial perspective.

History of Ketones

Ketones are nothing new, it is just our understanding that has changed. beginning, in 1865 scientist discovered a molecule called acetoacetate in the urine of diabetic patients. Acetoacetate is a ketone or also known as a ketone body. Through discovering acetoacetate ultimately led them to identify BHB.

In identifying them, they began seeing BHB in high concentrations in uncontrolled diabetics (Ketoacidosis), thus leading scientist to label ketones as bad. However, as our understanding has grown this was shown to be short-sighted and to predominantly be a factor for uncontrolled diabetics patients.

Ketoacidosis is Not Ketosis

I know it sounds similar but they are the same.

Ketoacidosis or Diabetic Ketoacidosis (DKA) is a complication of type 1 diabetes mellitus. Associated with a dangerously high combination of ketones (much higher than ketosis) and blood sugars which makes your blood too acidic. As limited insulin is available for the cells to adequately uptake the sugar (glucose) in the blood to use for energy. Ultimately this can alter the normal functioning of internal organs like your liver and kidneys. It is a critical condition that requires prompt treatment as it is a life-threatening condition and often occurs quickly within as little as 24hrs.

DKA Ketone levels can increase up to 20-25 mM, which decreases blood pH, whereas a state of ketosis is determined as 0.5-3mM. With an upper threshold of 7-8 mM (e.g. during very-low-calorie Keto Diet and use of exogenous ketone supplements).

DKA is a predominantly a factor for type 1 diabetes but individuals with type 2 diabetes who have little or no insulin production, need to be careful as it can occur if not controlled.

Ketone Supplements:

  • Ketone salts: This is the form found in most ketone supplements available on the market. Ketone salts are a compound consisting of a mineral ion, such as sodium (Na+), potassium (K+), and BHB. Ketone salts are high in electrolytes; so they can aid replenishing electrolytes lost in urine while on the ketogenic diet.
  • Ketone esters: Ketone esters are primarily used in research and are not currently available to consumers. This form consists of pure beta-hydroxybutyrate or Acetoacetate without other additives.
  • MCT Oils: Medium chain triglycerides (MCT) doesn’t contain BHB but has been shown to moderately raise BHB levels. MCT’s require a greater amount of processing than other exogenous ketones thus taking longer to get into ketosis. Along with this, MCT’s are a more calorie dense which could be counterproductive for those needing to watch their caloric intake.

What Ketone Supplements do I use?

I personally utilise a mix of MCT Oils and Ketone Salts. I have used them for close to two years now and couldn’t imagine life without them especially the Pruvit (ketone salts).

My goal is performance and un-tapping my potential, I can’t settle for suboptimal, I want to always be performing at my best. Therefore, I use these supplements in many varying capacities from training and racing (triathlon), speeding up my recovery, to increase my mental capacity and clarity (ps. I am functioning on ketones as I write the majority of my blog posts 😉 ). Aside from performance end I also utilise Pruvit for longevity and to keep hunger at bay and extend my fasts so perfect for travel or when on the go with no good food insight or time, this gets me through these dangerous moments and keeps me functioning at a high level without hunger pains or cravings.

MCT Oils (Bulletproof or Melrose): I use this mostly when I need a little bit of mental and energy boost, but mostly to keep my hunger at bay. Plus sometimes to blunt the effects of those carbohydrate treats for me this normally means MCT Oil on my fruit salad. 

Ketone Salts (Pruvit): MCT is great but nothing compares with Ketone Salts, this would have to the biggest performance enhancing supplement I have ever taken, it is my rocket fuel!

Mixing Things Up:

I have traditionally taken each supplement separately until recently when I came across research stating the benefits associated with a combination of both Ketone salts (BHB) and MCT’s. This combo has been shown to further elevate the BHB response in the blood. Plus as it has a delayed gastric absorption it extends and sustains a higher elevation of blood ketone level over a longer period. The combination is looking extremely promising as it appears to be better than either ketone salts or MCT’s alone. Even better, it has been reported that it may remove the adverse gastrointestinal emptying effects of MCT oil that is often associate when MCT is taken on its own. However, further research is required to identify ratios and best application

Recently I have been playing around with my own ratios and I have introduced MCT oils into my staple long ride fuel of ketone salts and so far it has been great but I will keep you all posted with how I get on.

Why Pruvit?

Pruvit or Keto OS, which stands for “Ketone Operating System,” They were the first to patent to ketone technology, meaning they are most widely researched and used. Pruvit, is now one of the quickest growth nutrition based companies and has posted 400% year-to-year growth since its inception and is showing no signs of slowing down as it has recently moved into Canada, Asia, and Australia.

 

“I Need to Try Ketones for Myself!”

Flick us at Taylored a message and we can get you set you up with a trial.

[email protected]

Subject: Ketone Trial

 

Keto: Everything You Need to Know

The Ketogenic protocol or more commonly known as Keto is growing in popularity and no doubt you have heard about it, but are probably wondering what it is and why is there so much hype around it?

There is often a lot of confusion around what is keto and if it is right for particular individuals. It is important to remember everyone has different needs and requirements and the keto diet is not a panacea! However, for those that it is beneficial for, it has shown to have some profound effects, especially in aiding in chronic health conditions.

From High Fat Low Carbohydrate (HFLC), Paleo to Keto and everything in between there is some great confusion around the differences between them and what they are and what is the best approach. It becomes easy to get confused as within each approach (HFLC, Paleo & Keto) there is multiple sub-approaches to the protocols. For example, someplace greater or less focus on greens or proteins than others. It is no wonder everyone is lost and not sure where to start. My goal with this article is to cut through all this and simplify a very overcomplicated topic to arm you with the knowledge to make the best decision for your individual needs.

Let’s first define each of the key protocols, their history, philosophy and approach to nutrition.

 

1. Paleo protocol

Is the true ancestral approach that has been designed around how our ancestors used to live in the Palaeolithic Era.

Why? Our ancestors were lean, fit and remarkably free of chronic inflammatory disease. It works off the evolutionary process that for 66,000 generations, humans ate primarily meat, fish, fruits and vegetables, nuts and seeds, and some starchy plants. While being physically active and not sitting for long periods.

For this reason, the Paleo approach aims to emulate our ancestors as much as possible, moving away from processed foods to a wholefoods diet that has more of a balanced split between fat, carbohydrate, and protein.

 

2. Ketogenic protocol (Keto)

The ketogenic protocol is very low-carb, that replaces carbs with high amounts of fat that triggers the body’s natural metabolic process known as “ketosis.” Through restricting carbohydrates, you deprive your body of its natural fuel source, glucose, this forces the body to burn stored fat for fuel instead of glucose. This process promotes your liver to produces “ketones”, a type of fatty acid, and sends them into your bloodstream where your muscles and other tissues can use them as fuel. Ketones are your 4th fuel substrate so fat, protein, carbohydrate, and ketones. It was once believed producing ketones (ketosis) was dangerous as it was thought to be a catabolic state but with the endless amounts of new research, it has been shown to be a preferable source of fuel for humans, offering wide-ranging benefits. One of the quickest ways to achieve a state of Ketosis is fasting, however, it can also occur in the absence of glucose within your diet. External sources such as Exogenous Ketone Supplements have also been shown to greatly speed up this pathway achieving ketosis within 30 mins vs a few days for nutritional ketosis. Exogenous Ketones can be a great aid, especially in the early phases of a ketogenic diet and when looking for optimal performance, I will discuss these in my next article to provide you with a more in-depth understanding.

What does this state of ketosis achieve:

History & Application:

The ketogenic protocol was first coined and used clinically in the 1920s as an alternative therapy for children with epilepsy. However, fasting which also puts you into a ketogenic state is a key component of most, if not all, religions and has been used to treat disease for thousands of years.

Nowadays, people use the keto protocol primarily for:

  • Weight loss
  • Increased Energy & Mood
  • Increased mental clarity & Focus
  • Increased Performance (Mental & Physical)
  • Better Sleep
  • Faster Recovery
  • Longevity

Chronic Health Conditions that might Benefit from Keto:

  • Type 2 Diabetes
  • Cancer (glycolytic driven cancers)
  • Multiple Sclerosis (MS)
  • Epilepsy
  • Metabolic Syndromes
  • Traumatic brain injury (TBI)
  • Alzheimer’s disease
  • Dementia
  • Parkinson’s Disease (PD)
  • Autism spectrum disorder (ASD)  
  • Migraine headaches
  • Gastrointestinal conditions eg. Irritable Bowel Syndrome (IBS)
  • Skin conditions eg. acne vulgaris, acne rosacea, eczema, and psoriasis

Conditions that are Contraindications Warrant Caution:

  • Those with genetic conditions that affect fatty acid metabolism, including primary carnitine deficiency, pyruvate carboxylase deficiency, etc.
  • Pregnancy. The exception may be gestational diabetes, but even then a low-carb diet with some whole-food carbohydrates is a safer choice, provided the patient can reach the proper blood sugar targets.
  • People with gallbladder disease, or no gallbladder at all, since they can have trouble digesting fats.
  • People with kidney disease, including a history of kidney stones. Some studies suggest that keto can benefit patients with kidney failure, but patients with other kidney issues may be harmed.
  • People with HPA axis dysfunction and high levels of chronic stress.

(Chris Kresser, 2018)

Can this state be measured?

Yes, there are multiple methods of testing, from breath, blood to urine. As everyone will respond differently it is a great idea, especially early on, to track and quantify what constitutes as being in a state of ketosis. After a while, you will develop the ability to associate the feelings and responses linked with the state.

Although it is a great idea to track, I personally believe too many people begin to fixate on the numbers aiming to achieve deeper states. A higher number does not necessarily mean you are getting any more benefit and chasing the number could be costing you in other areas such as increased stress response. The bottom line, don’t get carried away chasing numbers.

Three methods of testing Ketones:

  1. Urine sticks are an inexpensive method that has been shown to be reliable in the early adaptation phase but once adapted not so reliable. Why? Your body becomes efficient at utilising ketones so you won’t excrete them through urine to the same extent, therefore showing a lower reading than it truly is. You can pick these sticks up from most pharmacies reasonably easily.
  2. Blood is known as the more reliable measure and often offers the ability to test glucose levels as well. The most popular handheld blood testing device is Precision Xtra.
  3. Breath Testing is one off upfront cost. Although it is less accurate than blood, many still prefer it as it is simple to use with no need to take blood. One of the most popular handheld devices is the Ketonix

Give me the Numbers:

The state of Ketosis has been widely debated. Mostly due to individual variance and the fact that is not like a switch, it is a gradual shift. It is now widely accepted and used within literature that 0.5mmol/L and above is defined as being in a ketogenic state. Scientists Jeff Volek and Stephen Phinney, pioneers within the field, described in their book “The Art and Science of Low-Carbohydrate Living“  ‘light nutritional ketosis’ as between 0.5mmol/L and 1.0mmol/L and ‘optimal ketosis’ is between 1.0mmol/L – 3.0mmol/L.”. However, as mentioned, everyone is different so these numbers do not make or break and they should be utilised as guides

 

3. High Fat Low Carbohydrate (HFLC) protocol

This one says it all in the title, it is all about ditching the carbohydrate and replacing with healthy fats. HFLC is very similar to Keto and even some consider them the same. I often find people who think they are leading a keto diet are actually HFLC and there is nothing wrong with this, it just depends on your goals and what works best for you as an individual. The biggest difference is the carbohydrate intake with HFLC you can eat between 50-150 grams where keto is between 20-50 grams. I spent the month of July discussing HFLC and the effects of carbohydrate so I have plenty of information to look further into, for the time being, I will just offer a brief overview. It is basically eating a greater percentage of healthy unprocessed fats, in replacement of all the refined carbohydrates that are consumed in the Western Diet.

The similarities across all three protocols

  • Less Carbohydrates than standard Western Diet (Fat: 20-30%, Protein 10-35% & Carbohydrate 45-60%). To learn more about how we got the history of the food pyramid to check out one of my previous posts Food Pyramid: We Got It Wrong! And to learn more about the effects of excessive carbohydrates I suggest reading this post Let’s Talk Science: High Carbohydrate Vs High Fat
  • Increase in the consumption of whole foods. Reduction if not removal of processed foods

The biggest differences between the three protocols:

It is important to note that some of these factors also apply within each protocol as well and as mentioned above there is a wide number of subgroups within each protocol.

Macronutrients (carbs, proteins, and fats): Macronutrients is the obvious difference across the three protocols.

  • Keto: Fat: 80%, Protein: 15% & Carbohydrate: 5%
  • Paleo: Fat: 28-47%, Protein: 19-35% & Carbohydrate: 22-40%
  • HFLC: More of a lifestyle change so no defined macro breakdown. However, it involves limiting carbs as much as possible, aiming to keep within 50-150 grams per day.

Protein Intake: This is one of the most debated topics and you will see variance not only across paleo to keto but within each protocol itself. Mostly due to the fact that excessive protein can lead to the bodies survival mechanism gluconeogenesis (production of turning protein into carbohydrate). It is believed if you deplete your carbohydrate stores and then replace with large amounts of protein it can lead to this process occurring and even though you are not eating carbs your body is creating them. There is a great academic debate going on at the moment. My current opinion and the opinion of the majority is that protein is not a key concern and it is not something you should restrict, as it is such a key component in maintaining and building tissue within the body, therefore especially important for athletes.

To speak to gluconeogenesis, it is important to remember that this is a highly un-efficient mechanism that is the last resort. Unless you are depleted of all your fat stores, which is near impossible, it is easier for your body to use your fat over going through this taxing process.

Fruit: As Paleo aims to emulate our ancestors, fruits are fine to eat. However, when following a ketogenic protocol and carbohydrates being very restricted, the majority of fruits do not fit within the requirements. For this reason, fruit is often restricted in keto. This is not to say you can not eat fruit if you can keep it within the Marcos (Carbohydrate under 5-8%). Keto individuals will traditionally stay clear of white fruits like banana, apples, pears etc as they produce a high glucose response and possess a greater amount of carbohydrate; for example a banana (Average size: 118 grams) has approximately 27 grams of carbs, this one banana alone exceeds the strictest of definitions of keto. Interestingly the carb count will drop the greener the banana. Instead, ketogenic people will often replace these fruits with vibrant colored and antioxidant-rich fruits like berries. For example; 100 grams of Strawberries is 7.68 grams of carbs.

Vegetables: Many believe these protocols are just bacon and oils, void of any vegetables. That is a whole different diet again, Carnivore diet which is growing popularity at the moment. This is an article in itself but put simply, in my opinion, this is not a sustainable long-term diet.

When it comes to vegetables due to the fiber content in vegetables you would be hard pressed to overeat and kick yourself out of ketosis with spinach, zucchini, lettuce, asparagus and kale on a keto diet. Like anything there are some you need to tread more carefully with eg: Bell Peppers (yellow Specifically), Brussels Sprouts, and beans, these possess great carb count. Myself and many others within Keto, HFLC, and Paleo believe vegetables should be the foundation of the diet due to the richness of micronutrients and antioxidants important for health. Many of which actually aid in digesting and removing harmful oxidative stressors.

Dairy: In the strict Paleo sense, dairy of any form was not consumed in the Palaeolithic Era, other than human milk in the infancy of course. It just wasn’t very practical to milk wild game. Whereas keto and HFLC are all about dairy, that is if you can handle it.

 

Reference:

Allen, B. G., Bhatia, S. K., Anderson, C. M., Eichenberger-Gilmore, J. M., Sibenaller, Z. A., Mapuskar, K. A., … Fath, M. A. (2014). Ketogenic diets as an adjuvant cancer therapy: History and potential mechanism. Redox Biology, 2(1), 963–970. https://doi.org/10.1016/j.redox.2014.08.002

Dashti, H. M., Mathew, T. C., Hussein, T., Asfar, S. K., Behbahani, A., Khoursheed, M. A., … Al-Zaid, N. S. (2004). Long-term effects of a ketogenic diet in obese patients. Experimental and Clinical Cardiology, 9(3), 200–205. https://doi.org/10.3390/nu8050289

Deng-Bryant, Y., Prins, M. L., Hovda, D. A., & Harris, N. G. (2011). Ketogenic diet prevents alterations in brain metabolism in young but not adult rats after traumatic brain injury. Journal of Neurotrauma, 28(9), 1813–1825. https://doi.org/10.1089/neu.2011.1822

Di Lorenzo, C., Curra, A., Sirianni, G., Coppola, G., Bracaglia, M., Cardillo, A., … Pierelli, F. (2013). Diet transiently improves migraine in two twin sisters: possible role of ketogenesis? Functional Neurology, 28(4), 305–308.

Evangeliou, A., Vlachonikolis, I., Mihailidou, H., Spilioti, M., Skarpalezou, A., Makaronas, N., … Smeitink, J. (2003). Application of a ketogenic diet in children with autistic behavior: pilot study. Journal of Child Neurology, 18(2), 113–118. https://doi.org/10.1177/08830738030180020501

Gasior, M., Rogawski, M. A., & Hartman, A. L. (2006). Neuroprotective and disease-modifying effects of the ketogenic diet. Behavioural Pharmacology, 17(5–6), 431–439. https://doi.org/10.1097/00008877-200609000-00009

Herbert, M. R., & Buckley, J. A. (2013). Autism and dietary therapy: case report and review of the literature. Journal of Child Neurology, 28(8), 975–982. https://doi.org/10.1177/0883073813488668

Hu, Z.-G., Wang, H.-D., Qiao, L., Yan, W., Tan, Q.-F., & Yin, H.-X. (2009). The protective effect of the ketogenic diet on traumatic brain injury-induced cell death in juvenile rats. Brain Injury, 23(5), 459–465. https://doi.org/10.1080/02699050902788469

Mychasiuk, R., & Rho, J. M. (2017). Genetic modifications associated with ketogenic diet treatment in the BTBR(T+Tf/J) mouse model of autism spectrum disorder. Autism Research : Official Journal of the International Society for Autism Research, 10(3), 456–471. https://doi.org/10.1002/aur.1682

Paoli, A., Bianco, A., Damiani, E., & Bosco, G. (2014). Ketogenic diet in neuromuscular and neurodegenerative diseases. BioMed Research International, 2014(2). https://doi.org/10.1155/2014/474296

Prins, M. L., & Matsumoto, J. H. (2014). The collective therapeutic potential of cerebral ketone metabolism in traumatic brain injury. Journal of Lipid Research, 55(12), 2450–2457. https://doi.org/10.1194/jlr.R046706

Remahl, S., Dahlin, M. G., & Amark, P. E. (2008). Influence of the ketogenic diet on 24-hour electroencephalogram in children with  epilepsy. Pediatric Neurology, 38(1), 38–43. https://doi.org/10.1016/j.pediatrneurol.2007.09.002

Schmidt, M., Pfetzer, N., Schwab, M., Strauss, I., & Kämmerer, U. (2011). Effects of a ketogenic diet on the quality of life in 16 patients with advanced cancer: A pilot trial. Nutrition & Metabolism, 8(1), 54. https://doi.org/10.1186/1743-7075-8-54

Stafstrom, C. E., & Rho, J. M. (2012). The ketogenic diet as a treatment paradigm for diverse neurological disorders. Frontiers in Pharmacology, 3 APR(April), 1–8. https://doi.org/10.3389/fphar.2012.00059

Storoni, M., & Plant, G. T. (2015). The Therapeutic Potential of the Ketogenic Diet in Treating Progressive Multiple Sclerosis. Multiple Sclerosis International, 2015, 1–9. https://doi.org/10.1155/2015/681289

Volek, J. S., Phinney, S. D., Forsythe, C. E., Quann, E. E., Wood, R. J., Puglisi, M. J., … Feinman, R. D. (2009). Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids, 44(4), 297–309. https://doi.org/10.1007/s11745-008-3274-2

Alternate Approach to Fueling the Endurance Athlete

Our last post we discussed carbohydrate (CHO) as a primary fuel source and factors that need to be considered. In this post we want to shed light on an alternative approach to fueling as an endurance athlete and how it stacks up against traditional methods.

With the growing body of literature investigating the current ‘traditional and text book’ endurance based nutrition, I wanted to take sometime to highlight some of the newer evidence along with an alternate strategy. I am not saying this is a strategy for everyone, as in so many areas of our sport (e.g. training and nutrition) there is so much individual variance. However, with my clinical and personal experience if done correctly, I have found an approach that works for the majority of clients and is something I highly suggest you consider and test out, not only from a performance standpoint but for your overall health as well.

 

Background/ Training Nutrition

Before talking about race nutrition (particularly Ironman) you must first understand training nutrition. The science has made some significant developments in recent years and I want to identify what these recent changes are and then compare them to traditional nutritional methods and try help you identify which is the best approach for you!

 

What is Traditional/Textbook Endurance Nutrition?

This nutritional method is based around the intake of CHO and the ability to load (before) and continually replenish CHO stores during exercise.

 

What does this mean?

Challenge Roth 2014

Typically our bodies can only use ~1g of CHO / kg of Body Weight / Hour. We are constantly told that to perform at a high level or merely ‘last the distance’ in any endurance event requires us to be fueled solely by CHO. Go to any endurance event or even give “Ironman Nutrition” a quick google and you will see this is still a common thought. Ironman itself even puts on a pre-race dinner “Pasta Party” based around this concept, with the intention of CHO loading (I pre-ate before attending).

But sport science is a new science so we are always learning and older practices (nutritional or other) are being re-investigated and newer methods are always being developed and tested. In the case of nutrition for ultra events the science is evolving and initially these challenge all my previous beliefs, creating a lot of confusion (even for me, someone who has studied sport science).  But, in taking a step back I was able to analyse from a non-bias standpoint and used a bit of logic to allow me to see the potential of this new nutritional strategy.

 

So, what was being suggested? 

A flipping of the traditional method on it head! Out with the CHO during training and in with the fat! With CHO so ingrained in our culture not only as athletes but also in general day to day life, it can be challenging.

There are plenty of methods that now utilise this approach with some variance within them: High Fat Low Carb (HFLC), Very Low Carb and High Fat (VLCHF), Paleo, Ketogenic, Aktins or Modified Akins. Despite their differences (mainly in their name choice) they all work on a similar premise, that is to reduce CHO used during low- moderate intensity (sparing our very very limited body CHO stores for those rare times when we need to sprint finish) and increasing our efficiency at using fat as a fuel source. Some of the diets listed above are a bit more extreme than others. So which one is best? Again it comes down to you and what suits YOU best.

 

My goal: My focus is always on efficiency and maximising performance both physical and mental. Therefore, I put the high fat strategy to the test against Ironman, with the intention of be able to utilise fat a primary fuel source throughout the race.

 

Fat Adapted Athlete or Metabolically flexible

Put simply you have the ability to use fat as a fuel during exercise and this saves your bodies limited CHO stores (~500-600g even when you eat a lot of CHO in your diet). This shift allows you to move away from a limited and finite fuel source to one that is unlimited!!!!!

At the lower exercise intensities required during an Ironman (we are exercising for 8-17 hours) the increased use of our fat stores may mean less frequent refueling and less reliance on external fueling methods (now no stress now if you drop that one gel out on course). Another added benefit of using your fat stores is enhanced fat loss, great for body composition.

Your health is also improved by shifting to a ‘high good fat’ diet. This is due to the fact that when you use fat as a fuel you do not create the inflammatory response that we see with CHO. Less inflammation is great for supporting a healthy body (Let’s talk Science: High Carbohydrate Vs High Fat)

The ‘traditional’ CHO method would argue that fat use in exercise limits your ability to perform at the top end of your chosen sport (endurance and even anaerobic based power athletes). But the recent research has debunked that argument. Some of the best triathletes would consider themselves to be high fat/ low carb and they are winning events at an amateur and professional level.

 

Put in to practice: Proof is in the pudding

 

Pro Athletes: It is hard to say exactly who is and who isn’t but those to the best of my knowledge are listed below. Along with being pro athletes a lot of them are also coaches themselves as well.

Simon Cochrane: 1st Rotorua & Karapiro Half Ironman, 3rd place IM Japan, 3rd IM Taiwan, 3rd IM Philippines. IM New Zealand PB 8:21

Jan van Berkel: 1st Ironman Switzerland (in record breaking time), 5th 2018 IM Texas (7.48.40); 4th 2018 IM New Zealand

Tim Reed: 1st 2018 IM 70.3 Vietnam, 2nd  2017 IM 70.3 Asia Pacific Championships, Western Sydney, 2nd IM Australia, Port Macquarie

Dougal Allan: 1st 2018 Motatapu Xterra, 1st 2018 Redbull Defiance, 2nd 2017 IM Western, Australia

Kyle Buckingham: 1st 2018 IM  African Championships

 

Coaches / Athletes: Who are renowned for the High fat approach to training

Dan Plews (Coaching Service: Plew & Prof): 1st 2018 Age grouper in IM New Zealand – 8:35

Bevan Mckinnon (Coaching Service: Fitter): 1st 2016 Kona IM in Age group World Championships  

 

This does not mean it will work for everyone!! I just wanted to highlight that this is a strategy being utilised by top athletes, showing that its does not reduce your performance, in fact it may have the opposite effect. These are just some of the top athletes well known for this approach but there are plenty more and it is a strategy that is continually growing in popularity as science proves the validity of this nutritional strategy in performance and health measures.

 

How does a Carbohydrate Athlete match up to a Fat Adapted Athlete

I wanted to keep it simple as I know this topic it can become overwhelming to most. Listed below are a comparison of the two strategies.

Key Things to consider:

Below are some key factors to consider before jumping into this approach and often the biggest mistakes I see athletes make.

 

  • CHO Tolerance: Carbohydrate tolerances or insulin sensitivity (ability to produce adequate insulin when required, to ensure efficient uptake of carbohydrate) will vary from person to person. There is no one size fits all macro breakdown there are just guidelines!

 

  • A-Type Personality: The biggest mistake I see especially in the A-Type personality world of triathlon is athletes going to extreme to quick. Just like physical training this shift in fuel substrate should be a gradual adaptation. I highly suggest easing into it, you should never be suffering (eg starving) if so you are pushing your limits too much! However, if done correctly the benefits to your health, performance and longevity will be profound!

 

  • Female Athlete: Females must also be cautious in adapting this approach as you traditionally require more CHO and must consider the impact of your menstrual cycle and design your intake accordingly. For this reason there doesn’t seem to be too many Pro female Ironman athletes currently, I have heard that Melissa Hauschildt (1st Female 2018 IM Texas – North American Championships) is high fat athlete but that has not been confirmed. I think this is something we will see more as we learn how to better cater the approach to the specific demands female body. As quoted by Stacey Sims: “Women are not small men!”

 

  • Train Low Race High: Once fat adapted, athletes to often approach their racing the same as there training void of or minimal CHO. If you want to optimise your performance you buffer your CHO stores so that you can utilise both CHO and fat substrates to their full potential. Although,  this has been recently shown to be especially important in more competitive and elite athletes than those working at ;lower intensities 

 

Take home message:

No detrimental effect in performance, less need for refueling, fat loss and faster recovery, it sounds pretty good to me!

I will say it again that as with any nutritional approach there is no one size fits all approach, you must find what works for you! Sometimes that means some long term self experimenting. Take it gradually don’t go all out and end up with Keto Flu.

 

References:

Burke, L. M., & Hawley, J. A. (2002). Effects of short-term fat adaptation on metabolism and performance of prolonged exercise. Medicine & Science in Sports & Exercise, (2). https://doi.org/10.1249/01.MSS.0000027690.61338.38

Burke, L. M., Wood, C., Pyne, D. B., Telford, D. R., & Saunders, P. U. (2005). Effect of carbohydrate intake on half-marathon performance of well-trained runners. International Journal of Sport Nutrition and Exercise Metabolism, 15(6), 573–589.

Campbell, C., Prince, D., Braun, M., Applegate, E., & Casazza, G. A. (2008). Carbohydrate-supplement form and exercise performance. International Journal of Sport Nutrition and Exercise Metabolism, 18(2), 179–190.

Carey, A. L., Yeo, W. K., Carey, A. L., Burke, L., Spriet, L. L., & Hawley, J. A. (2011). Fat adaptation in well-trained athletes : Effects on cell metabolism REVIEW / SYNTHE Fat adaptation in well-trained athletes : effects on cell metabolism. Applied Physiology Nutrition and Metabolism, (April 2016). https://doi.org/10.1139/H10-089

Cipryan, L., Plews, D. J., Ferretti, A., Maffetone, P. B., & Laursen, P. B. (2018). Effects of a 4-week very low-carbohydrate diet on high-intensity interval training responses. Journal of Sports Science and Medicine, 17(April), 259–267.

Harvey, C. J. C., Schofield, G. M., & Williden, M. (2018). The use of nutritional supplements to induce ketosis and reduce symptoms associated with keto-induction : a narrative review. PeerJ. https://doi.org/10.7717/peerj.4488

Havemann, L., West, S. J., Goedecke, J. H., Macdonald, I. A., Gibson, A. S. C., Noakes, T. D., … Fat, E. V. L. (2018). Fat adaptation followed by carbohydrate loading compromises high-intensity sprint performance. Journal of Applied Physiology, 194–202. https://doi.org/10.1152/japplphysiol.00813.2005.

Jentjens, R. L. P. G., & Jeukendrup, A. E. (2005). High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. The British Journal of Nutrition, 93(4), 485–492.

Jeukendrup, A. E., & Wallis, G. A. (2005). Measurement of Substrate Oxidation During Exercise by Means of Gas Exchange Measurements. Int J Sports Med, 26(S 1), S28–S37. https://doi.org/10.1055/s-2004-830512

Jeukendrup, A. (2008). Carbohydrate feeding during exercise. European Journal of Sport Science (Vol. 8). https://doi.org/10.1080/17461390801918971

Malatesta, D., Brun, J.-F., Astorino, T. A., Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising maximal fat oxidation during exercise: determinants and normative values. Frontiers in Physiology, 9(599). https://doi.org/10.3389/fphys.2018.00599

Maunder, E., Kilding, A. E., & Plews, D. J. (2018). Substrate Metabolism During Ironman Triathlon: Different Horses on the Same Courses. Sports Medicine. https://doi.org/10.1007/s40279-018-0938-9

Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising Maximal Fat Oxidation During Exercise : Determinants and Normative Values. Frontiers in Physiology, 9(May), 1–13. https://doi.org/10.3389/fphys.2018.00599

Newman, J. C., & Verdin, E. (2014). Ketone bodies as signaling metabolites. Trends in Endocrinology & Metabolism, 25(1), 42–52. https://doi.org/10.1016/j.tem.2013.09.002

Oliveira, E. P. De, & Burini, R. C. (2014). Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress. Nutrients, 4191–4199. https://doi.org/10.3390/nu6104191

Painelli, V. D. S., Nicastro, H., & Jr, A. H. L. (2010). Carbohydrate mouth rinse : does it improve endurance exercise performance ? Nutrition Journal, 2–5.

Paoli, A., Grimaldi, K., Agostino, D. D., Cenci, L., Moro, T., Bianco, A., & Palma, A. (2012). Ketogenic diet does not affect strength performance in elite artistic gymnasts. Journal of the International Society of Sports Nutrition, 1–9.

Peters, S. J., Amand, T. A. S. T., Howlett, R. A., Heigenhauser, G. J. F., Spriet, L. L., Ln, O., … Lawrence, L. (1998). Human skeletal muscle pyruvate dehydrogenase kinase activity increases after a low-carbohydrate diet. The American Physiological Society, (8).

Peters, S. J., Harris, R. A., Wu, P., Pehleman, T. L., Heigenhauser, G. J. F., Spriet, L. L., … Spriet, L. L. (2018). Human skeletal muscle PDH kinase activity and isoform expression during a 3-day high-fat / low-carbohydrate diet. American Journal of Physiology-Endocrinology and Metabolism, 1, 1151–1158.

Peters, S. J., & Leblanc, P. J. (2004). Nutrition & Metabolism Metabolic aspects of low carbohydrate diets and exercise. Nutrition & Metabolism 2004, 8, 1–8. https://doi.org/10.1186/1743-7075-1-7

Pfeiffer, B., Stellingwerff, T., Hodgson, A. B., Randell, R., Res, P., & Jeukendrup, A. E. (2012). Nutritional Intake and Gastrointestinal Problems during Competitive Endurance Events. Medical Science in Sports and Exercise, (7), 344–351. https://doi.org/10.1249/MSS.0b013e31822dc809

Pfeiffer, B., Stellingwerff, T., Zaltas, E., & Jeukendrup, A. E. (2010). CHO oxidation from a CHO gel compared with a drink during exercise. Medicine and Science in Sports and Exercise, 42(11), 2038–2045. https://doi.org/10.1249/MSS.0b013e3181e0efe6

Prado, E., Roberto, D. O., & Burini, C. (2014). Gastrointestinal Complaints During Exercise : Prevalence , Etiology , and Nutritional Recommendations. Sports Medicine, 44, 79–85. https://doi.org/10.1007/s40279-014-0153-2

Stellingwerff, T., Spriet, L. L., Watt, M. J., Kimber, N. E., Hargreaves, M., Hawley, J. A., … Pdh, D. (2018). Decreased PDH activation and glycogenolysis during exercise following fat adaptation with carbohydrate restoration. American Journal of Physiology-Endocrinology and Metabolism, 380–388. https://doi.org/10.1152/ajpendo.00268.2005.

Stuempfle, K. J., Hoffman, M. D., & Hew-butler, T. (2013). Association of Gastrointestinal Distress in Ultramarathoners with Race Diet Association of Gastrointestinal Distress in Ultramarathoners with Race. International Journal of Sport Nutrition and Exercise Metabolism, 2, 103–109.

Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., … Phinney, S. D. (2015). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, 65(3), 100–110. https://doi.org/10.1016/j.metabol.2015.10.028

Volek, J. S., Noakes, T., & Phinney, S. D. (2015). Rethinking fat as a fuel for endurance exercise. European Journal of Sport Science, 15(1), 13–20.

Zinn, C., Wood, M., Williden, M., Chatterton, S., & Maunder, E. (2017). Ketogenic diet benefits body composition and well-being but not performance in a pilot case study of New Zealand endurance athletes. Journal of the International Society of Sports Nutrition, 1–9. https://doi.org/10.1186/s12970-017-0180-0

Zügel, D. (2016). Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon. International Journal of Sport Nutrition and Exercise Metabolism.

 

Effect of Carbohydrate & Athletic Potential

Are Carbohydrates Maximising your Athletic Potential?

Now that we have touched on some of the effects of carbohydrate on general health, let’s progress into carbohydrate as a primary fuel source in athletic events. In this article we will have a look at the literature and discuss how you can optimise your performance through the fourth discipline of triathlon, aka “fuel and nutrition”.

 

Limited Storage Capacity

The leading limitation of carbohydrate (CHO) as a fuel is it’s storage capacity (500-600 grams) and the need for continually refueling to maintain these stores. The rate of CHO absorption can be minimally manipulated and may depend on your CHO sources used. Interestingly the maximal CHO absorption capacity that has been achieved is 1.8g of CHO / min  (4,6). But CHO storage (500-600g) is dwarfed by fat storage (5+) kg even in a very lean individual). This is a phenomenal difference, this benefit alone should be enough to spike any endurance athletes attention. I say endurance athlete because any sport under 1-1.5 hr can store enough CHO to supply energy for their chosen activity, and in this case using fat as a fuel may not be the best strategy. But it is endurance athletes who regularly exceed this time threshold and who can really benefit from utilising fat as a fuel. However, this is only one benefit and there is a growing body of scientific evidence suggesting a wide range of other benefits that I will discuss and will benefit majority of athletes regardless of  the sporting event.

Source of Carbohydrate: Is it important?

Many athletes fail to recognise or understand the difference between different types of CHO. CHO can be divided into two main divisions, the rapidly oxidized CHO (up to ~60 g/hr or 1 g/min; include: glucose, maltose, sucrose, maltodextrin and amylopectin starch) and slower oxidized CHO (up to ~30 g/hr or 0.5 g/min; include: fructose, galactose, isomaltulose, trehalose and amylose). The reason for different oxidation rates is due to the different CHO sources using different CHO transporters in the gut and increasing the amount going from the gut to the blood. Therefore, ingestion of multiple transportable (glucose + fructose) CHO vs. single transportable CHO enhances exogenous  (external from body  eg food, supplements etc) CHO oxidation and increases performance (9)

Gels & Long distance Triathlon

To the best of my knowledge Zügel, (2016) (15), is the only study that has specifically looked at the administration of gels in long distance triathlon. A number of studies have looked at other shorter disciplines comparing gels to a liquid source of CHO with varied results. (1,2,12) Long distance triathlon possess several unique conditions compared to these sports such as, the inability to consume fuel while in the swim and possibly the change in body position across the three disciplines over the day that may impair gastric emptying (nutrition moving from the stomach into the intestine to be absorbed) and increase GI distress(11). In a study of long distance triathletes (15) the results suggested that gels compared to liquid CHO caused no difference in performance. But the study did show that people that consumed gels had an increase GI distress.

Gastrointestinal  Distress

As a CHO based athlete the need for continuous refueling is essential part of training and racing. But what we see is that sometimes these high and regular fuel intakes are closely related to Gastrointestinal (GI) distress. The ability to tap into endogenous fuel (produced internally in body) sources over exogenous fuel (external from body  eg food, supplements etc) would be extremely advantageous in minimising/preventing GI distress.

When consuming exogenous CHO, multiple transporters have been shown to not only increases CHO absorption but also aid in reducing GI complaints. Therefore, it is advantageous to consume CHO from multiple transporters, from a performance standpoint along with minimising GI distress. O’Brien, & Rowlands (2011) (8) concluded that a 0.8 ratio (0.8 fructose + 1.0 maltodextrin) presented the least amount of GI distress. If you are someone who is particular sensitive, this is an important consideration when selecting you personal fueling strategy.

Gut Traininability

Higher absorption of CHO is associated with less residual CHO in the intestine and it could prevent GI distress, an obvious potential strategy would be to increase absorptive capacity of the gut through training the gut to tolerate higher levels of CHO (15). However, more research is required.

Carbohydrate Mouth Rinsing

In recent years there has been emerging research around the ergogenic (performance enhancing) action via the central nervous system. It has been demonstrated that CHO mouth rinsing presents performance enhancing benefits in events 60 min or less. There is limited research in endurance based events (60 min+). But this could offer athletes the ability to bypass or reduce GI distress associated with CHO refueling, making it especially useful in the run segment of triathlon due to increase in GI distress seen with high impact and jaring activity. However, as an emerging area of research more depth is required to identify the exact mechanisms at play and to provide guidance on best practice for a strategy like this.

Metabolic flexibility

When it comes to optimising you your fourth discipline “Nutrition”, you need to look at what your current training load, the duration of the event you are training for and what is the best practice nutrition that will allow you to achieve your goals. For longer events (training 12 + hours a week and events greater than 2 hours in duration) the best possible nutritional approach would be to seek and attain metabolic flexibility.

So what is Metabolic flexibility:

When I say metabolic flexibility I am referring to your ability to adapt your fuel utilisation to meet the energy demands of the exercise stress which you are putting yourself through. For long distance events, low-moderate exercise intensity your body will be most efficient when utilizing fat as a fuel. You want to be an efficient fat burning machine, this will allow you spare your limited muscle glycogen stores so that when you need to use them for that all out maximal sprint finish, your body can adapt and change fuel sources from fat to CHO to meet energy demands.

By not aiming to achieve metabolic flexibility you are limiting your performance potential by not maximising your ability to utilise alternative fuel sources. I would even go as far to argue metabolic flexibility is one of the most performance enhancing strategies you can train to promote overall health, weight maintenance, longevity and sporting performance.

As a metabolically flexible athlete having the ability to shift from CHO to Fat as a primary fuel source (almost exclusively, very minimal CHO) when they are resting, sleeping and moving slowly is highly beneficial. One of the most beneficial components is that you are reserving your limited CHO to be utilised in higher intensity activities like sprinting. Therefore a metabolically flexible athlete or fat adapted athlete has the ability to maximise their substrate utilization and ensure optimal efficiency for endurance events. It is like fueling your body with diesel (fat) & high octane fuel (CHO), giving you the efficiency and endurance of the diesel coupled with the ability to tap into your high octane fuel when you need surge or increase intensity. Compared to fueling with one or the other on its own, this approach would seemingly limit your capacity to shift between the two when required.

To achieve this you need to look beyond the limited CHO and train your body to utilise other limitless fuel sources like fat alongside CHO to truly maximise your potential. In our next post we will compare the metabolically flexible fat adapted athlete vs the traditional high CHO based athlete.

 

References:

  1. Burke, L. M., Wood, C., Pyne, D. B., Telford, D. R., & Saunders, P. U. (2005). Effect of carbohydrate intake on half-marathon performance of well-trained runners. International Journal of Sport Nutrition and Exercise Metabolism, 15(6), 573–589.
  2. Campbell, C., Prince, D., Braun, M., Applegate, E., & Casazza, G. A. (2008). Carbohydrate-supplement form and exercise performance. International Journal of Sport Nutrition and Exercise Metabolism, 18(2), 179–190.
  3. Cipryan, L., Plews, D. J., Ferretti, A., Maffetone, P. B., & Laursen, P. B. (2018). Effects of a 4-week very low-carbohydrate diet on high-intensity interval training responses. Journal of Sports Science and Medicine, 17(April), 259–267.
  4. Jentjens, R. L. P. G., & Jeukendrup, A. E. (2005). High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. The British Journal of Nutrition, 93(4), 485–492.
  5. Jeukendrup, A. (2008). Carbohydrate feeding during exercise. European Journal of Sport Science (Vol. 8). https://doi.org/10.1080/17461390801918971
  6. Jeukendrup, A. E., & Wallis, G. A. (2005). Measurement of Substrate Oxidation During Exercise by Means of Gas Exchange Measurements. Int J Sports Med, 26(S 1), S28–S37. https://doi.org/10.1055/s-2004-830512
  7. Malatesta, D., Brun, J.-F., Astorino, T. A., Maunder, E., Plews, D. J., & Kilding, A. E. (2018). Contextualising maximal fat oxidation during exercise: determinants and normative values. Frontiers in Physiology, 9(599). https://doi.org/10.3389/fphys.2018.00599
  8. O’Brien W.J., Rowlands D.S. Fructose-maltodextrin ratio in a carbohydrate-electrolyte solution differentially affects exogenous carbohydrate oxidation rate, gut comfort, and performance. Am. J. Physiol. Gastrointest. Liver Physiol. 2011;300:G181–G189. doi: 10.1152/ajpgi.00419.2010.
  9. Oliveira, E. P. De, & Burini, R. C. (2014). Carbohydrate-Dependent, Exercise-Induced Gastrointestinal Distress, 4191–4199. https://doi.org/10.3390/nu6104191
  10. Painelli, V. D. S., Nicastro, H., & Jr, A. H. L. (2010). Carbohydrate mouth rinse : does it improve endurance exercise performance ?, 2–5.
  11. Peters, H.P., van Schelven, F.W., Verstappen, P.A., de Boer, R.W., Bol, E., Erich, W.B., de Vries, W.R. (1993). Gastrointestinal problems as a function of carbohydrate supplements and mode of exercise. Medicine and Science in Sports and Exercise, 25, 1211–1224. doi:10.1249/00005768-199311000-00003
  12. Pfeiffer, B., Stellingwerff, T., Zaltas, E., & Jeukendrup, A. E. (2010). CHO oxidation from a CHO gel compared with a drink during exercise. Medicine and Science in Sports and Exercise, 42(11), 2038–2045. https://doi.org/10.1249/MSS.0b013e3181e0efe6
  13. Prado, E., Roberto, D. O., & Burini, C. (2014). Gastrointestinal Complaints During Exercise : Prevalence , Etiology , and Nutritional Recommendations, 44, 79–85. https://doi.org/10.1007/s40279-014-0153-2
  14. Stuempfle, K. J., Hoffman, M. D., & Hew-butler, T. (2013). Association of Gastrointestinal Distress in Ultramarathoners with Race Diet Association of Gastrointestinal Distress in Ultramarathoners with Race, 2, 103–109.
  15. Zügel, D. (2016). Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon.