Waterloo Chiropractor, Physiotherapist and Registered Dietitian

Category

STEPHANIE BOVILLE

53650544 - foods high in carbohydrate on rustic wooden background. top view

marathonnurition

** H+P, Run Waterloo members, Runners’ Choice running club members and WCC members receive a $50 discount!

Let us help you take full advantage of what the latest research is showing with regards to endurance sports nutrition!  Stephanie has 6 years of post-secondary education at her disposal.  Learn more about her HERE.  Along with adapting to each individual’s needs, each session will include the following topics (and more):

Session 1: Initial Assessment and Workout Nutrition Optimization (1 hour)

Initial assessment and key initial changes such as protein distribution and pre/post workout.

Session 2: Training the Gut & Nutrition During (45 minutes)

How to train your gut to tolerate more carbs, how and when to take your carbs acutely before and during, how to accurate calculate and plan your fluid intake.

Session 3: Hydration continued and GI distress (45 minutes)

Other factors to consider when optimizing hydration and exactly how to modify your diet in the days leading into race day to decrease the odds of GI distress.  Touch open sleep and recovery.

Session 4: Carb loading (45 minutes)

How to shift your diet away from protein/fats/fibre toward carbs in that week pre-race.  How much and when to eat your carbs in the days leading into your competition.

Session 5: Supplement Review (45 minutes)

Vitamin D, dietary nitrates (beat juice), caffeine, salt pills, Omega-3s and beyond.  What do you need to be taking during?  What do you need to take directly before and during a race?  What actually works, and what should you stay away from?

PLUS:

  • 3 follow up e-mail discussions leading into your 2-3 key races.
  • A custom, detailed carb loading plan leading into your A-races.

This plan will arm you with what the most up-to-date research shows works.  Stephanie will help you ensure that you are properly fuelled and energized for race day so that you can reveal your full fitness potential!  If you are interested for yourself or a loved one, please contact us at (519)885-4930 or info@drdelanghe.com.

If you haven’t seen it, here it is- Canada’s NEW food guide.   So what exactly are the differences, and has it really changed that much?  Our registered dietitian, Steph Boville, has some thoughts!

foot guide

What I think of the new Canada’s Food Guide

To be perfectly honest, I rarely pulled out the old rainbow Food Guide when talking to my patients. If you don’t remember the old guide, it was a rainbow representing the 4 different food groups which were arranged in order of foods you needed the most servings from to the least. The main focus of the diet was on vegetables and fruit, followed by whole grains, milk and alternatives and finally the food group you needed the least servings of was meat and alternatives. From there they gave guidelines such as eat more vegetables than fruit, eat at least half your grains as whole grains, choose beans and lentils often etc. They then prescribed a number of servings for each food group based on age and gender.

The reason I didn’t use the guide was because it was meant to be an education tool to learn about different food groups and their purpose rather than provide practical steps to get someone to follow the prescribed servings.  Plus, people generally know the focus of their diet should be on vegetables and fruit but this needed to be more visual, practical and user friendly. For these reasons I found easier and more effective ways to communicate the information in the guide in my own way, not to mention nutrition is not a one-size fits all and therefore did not use the guide in my practice.

The New Guide

The new Canada’s Food Guide encompasses many important aspects of eating and also provides consumers with more specific guidelines about foods to choose more or less often in a very visual way. There has been a lot of hype about the new food guide, both good and bad (like everything… everyone has their own opinion!). I honestly think that the information has not changed, rather how it has been communicated has.  These changes in communication have been extremely positive.  The new Food Guide is very similar to values that guide my counselling style and advice.

The visual of the plate, with half the plate covered in a variety of deep colourful vegetables and fruit, a quarter of your plate as your whole, unprocessed grains and starches and a quarter of your plate as your plant or animal protein sources. This communicates very easily and simply how you want your plate to look compared to the prescription like recommended servings of the past Food Guide. The new guide still promotes the same values as before: eat real foods, include lentils and plant proteins, lean proteins, whole grain carbohydrates and more vegetables, with less sodium, saturated fats, processed foods and sugar. All of these values line up with my own personal beliefs and what the evidence shows.

There are a few things I really like about the new guidelines. It is more interactive and web-based rather than a physical pamphlet which may be better for our tech-savvy population. Not only is the visual of the plate very easy to see, understand and apply, but it also acknowledges the social aspect of food and promotes building a healthy relationship with food. This is also a foundational value of Bodzii (personalized nutrition and lifestyle coaching), where we think it is important to have both good food quality and a good food mentality. For example, viewing food in a positive light such as thinking of what a food can do for you, not to you. There is a wide range of information for consumers on practical ways to be mindful of your eating habits, benefits of cooking more often, ways to enjoy your food, benefits of when you eat meals with others, how to use food labels, and how to be aware of food marketing along with much more.

What about the dairy? Everyone is freaking out that dairy is no longer a “food group”. One thing I think the Food Guide needed to do was separate themselves from organizations and give an unbiased, easy to use guide for consumers in which takes “food politics” or influences out of the equation. Dairy is still in the guide, just as the other food groups such as grains and meat and vegetables are. However, there is a shift from food groups to a “macronutrient” like approach. This means that the dairy products are now represented in the protein portion of the plate. This DOES NOT mean that milk is considered unhealthy. As always, milk (soy, pea and cow milk) still provides us with protein, vitamin D and calcium for strong bones, teeth and muscle function.

Overall, the new changes to the Canada’s Food Guide are more in line with I have been teaching and promoting all along. The guide may not satisfy everyone depending on what “nutrition camp” you belong to such as keto, paleo or even elite athletes. It is not meant to be a one size fits all model, rather what the best evidence shows a balanced diet looks like for a healthy normal human. The bottom line is to not over complicate your nutrition. Focus on getting your vegetables, whole grains and lean proteins to meet your needs. Also remember to find ways to enjoy your food and to be mindful of what and how you eat along with striving to enjoy home cooked meals when possible.

I hope this helps to clear up some confusion you may have been experiencing with regards to this new guide.  If you have any additional questions, don’t be afraid to contact me at the clinic! 

wlflyer

Let us help you take control of your health!  Stephanie has 6 years of post-secondary education at her disposal.  Learn more about her HERE.  Along with adapting to each individual’s needs, each session will include the following topics (and more):

First visit: Initial assessment and diet optimization

Second visit: Science and role of carbohydrates and carbohydrate quality

Third visit: Quality fats, micronutrients and sleep optimization

Fourth visit: Intuitive eating and responding to hunger

Fifth visit: Planning and goal setting for transitioning out of dieting

Sixth visit: Wrap up and measurements

This plan will arm you with what the most up-to-date research shows works.  No fad diets, fasting, cleanses, or cutting out foods you love.  Stephanie will help you conquer your challenges not only from a dietary standpoint, but a biopyschosocial standpoint- your mind and behavior matters if this is going to work!

If you are interested for yourself or a loved one, please contact us at (519)885-4930 or info@drdelanghe.com.

Version 3

In general, our society is becoming more health conscious, which is great! People are living longer and are looking to feel younger as they age. I often work with aging athletes, and older adults to help provide guidance on how they can use different nutrition strategies to help them reach their goals, whether health or fitness related. One of the most common issue these I find older adults face including recovery, strength and body composition changes. If you are over 50 I would encourage you to keep reading!

Sarcopenia

Sarcopinia is the term used to describe the gradual muscle mass loss seen in older adults. We know that in general once you hit age 50, you start to lose about 1% of your lean body mass per year. This is concerning for a few reasons. First, the loss of muscle mass means you will also likely lose functionality, ie you may be unable to lift groceries like you used to. It also can result in changes in balance and stability which may lead to increased risk of falls. Lastly, because our muscle mass is a metabolically active tissue (ie it stores and burns carbohydrates and fats) the decreased muscle mass can decrease the metabolic efficiency and storage of carbohydrates and fats and can lead to development of chronic diseases such as cardiovascular disease or type 2 diabetes. This results in a huge stress on our health care system and therefore is important for us to think about nutrition strategies to maintain our muscle mass as we age.

Why do we lose muscle mass?

It is not known for certain why we lose muscle mass as we age, whether we have a general decreased muscle building and/or increased muscle breakdown or a lower sensitivity for turning on protein synthesis (ie it takes more protein to increase muscle building). Either way, in general this leads us to have higher muscle breakdown than build up, and thus a loss of lean tissue.

What can we do about it?

The first point I want to make is not related to nutrition. It is well known that resistance training is a VERY powerful stimulus of muscle building capacity and aged muscles respond to resistance training similar to young muscles. Resistance training in combination with very easy nutrition changes can help retain, maintain and possibly even build muscle mass in older adults.

 Nutrition Strategies

  1. Increase the protein intake

In a westernized country like Canada, we often get enough protein, however I do notice that older athletes or adults may still need to bump up their intake to maximize recovery. The reason for this recommendation is because we know that an older adult will not respond to a 20g dose of protein like a younger person would, and a higher dose of protein is needed to stimulate muscle building. Some older adults experience decreased appetite and will reduce portions, again we need to keep in mind we need more protein to maintain our muscle mass compared to when we were young!

  1. Protein quality is important

Research does show that soy protein vs whey or beef protein is less effective to stimulate muscle building. Even though soy is a complete protein (has the same amino acid make up as meat) it seems as though it is processed slightly different in the body. Mainly, the protein in soy seems to be digested slower resulting in less of an increase in amino acid levels in the blood and thus decreased stimulation of muscle protein synthesis. Very careful nutrition planning is necessary if you are an older adult who adheres to a vegetarian or vegan diet.

  1. Dairy

Dairy has the amino acid Leucine, which is a branch chain amino acid. It is a potent stimulator of muscle synthesis and can assist in maintaining lean mass. Not only is dairy a source of leucine, but adding a glass of milk to your meal will add about 8g of protein, which actually could be all the changes you need to make to meet the protein needs at your breakfast, lunch and dinner. In addition, consuming dairy products will provide you with calcium and vitamin D to assist in prevention of osteoporosis! Win win right?!

  1. Distribution

We talked about the amount, quality and now we get to the timing! If we look at typical protein amounts at each meal of the general population, we typically consume very little protein at breakfast, moderate amounts at lunch and a HUGE portion at dinner. This is a very skewed distribution of your protein and very little protein synthesis occurs until the dinner time, where not all of that protein can even be used and is wasted. Having multiple doses throughout the day at regular time intervals is the best method of feeding and maintain your muscle mass. You also want to make sure you place your protein at appropriate times to ensure adequate recovery from exercise bouts.

  1. Supplements

If you are an older adult who is engaging in regular exercise, supplements like protein powder might be common place in your dietary plan. One other supplement that has been shown to have some benefits for older adults is creatine. First we must understand that lifting a weight for 8reps the activity is more intense and it lasts very little time and therefore it will use anaerobic metabolism for the most part, which means that you will be using the phosphocreatine pathway to provide energy along with carbohydrates. The theory is that the more creatine in the muscle, the harder you can train, thus getting a better workout and getting a larger response of muscle strength and growth. It can be used to stimulate your muscle building potential. Research does show that proper dietary strategies + weight training + creatine supplementation can result in additional muscle building, increased strength and also increase in functional movement. Proper dosing is needed to elicit results, and there are a few contraindications for using such a supplement, independent assessment for this supplementation is needed.

As our population ages, it is predicted that at year 2050 a quarter (25%) of the population will be over the age of 65. This may put strain on our health care system, and therefore we need to make sure we do as much as we can to keep our bodies healthy as we age. For more information about how you can keep your body healthy as you age, book an appointment today!

Version 3

We are back at it again, and this time I want to talk a little bit about nutrition concerns for the male endurance athlete. If you have been following along with my previous blogs (if you haven’t, you should be!), you will recall we discussed how nutrition impacts the health and wellbeing of female endurance athletes, especially regarding stress fracture risk. You can find it here, if you would like to take a look back for a refresher.

For a quick recap, we discussed how endurance running is a huge metabolic demand, meaning it costs a lot to run fast for long periods of time. This can result in accidental under consumption of macronutrients (carbohydrates, fat and protein), energy, and ultimately vitamin/mineral intake, or purposeful restriction of food intake to achieve a desired level of thinness or body shape. Chronic under consumption, whether accidental or not, of both nutrient and energy, can cause some physiological changes in the body and can greatly increase your risk of bone related injuries.

It was typically believed that low energy availability (LEA), in the past known as the female athlete triad, only was a complication females encountered in sport, however it is now known that males also experience negative health and performance effects of LEA. It is possibly harder to detect in males, as there is no clear sign, such as loss of menstrual cycle, however that is why we need to be careful not to miss the subtle signs. In this article we will discuss what happens physiologically with LEA, and its effects on bone mineral density (BMD).

Physiological Changes
Under consuming energy can be a difficult concept to understand because calculations of exercise energy expenditure, basil metabolic rate and even energy intake are difficult to assess. Current research defines “Energy Availability” (EA) as the left over energy to be used for normal physiological processes after accounting for energy expenditure, which is expressed as kcal/kg of FAT FREE mass.

The EA equation= [energy intake- exercise energy expenditure] / fat free mass (kg)

Physiological Changes With LEA
– Decreased metabolic rate
– Increased cortisol (stress hormone)
– Decreased testosterone
– Signs include fatigue and decreased sex drive

Bone Mineral Density
There is ample evidence to suggest that an active individual have higher BMD than sedentary individuals. Within the athletic population swimmers and cyclists tend to have fairly low BMD due to non-weight bearing nature of the exercise. A study by Viner et al. looked at male and female cyclists with lower than expected BMD. The found that 70% had LEA across the entire training cycle, including pre season, competition and post season. This points to the theory that this particular group may have had low BMD due to their LEA. They found that 40% of the participants had low bone mineral density in their lumbar spine, and 10% had low bone mineral density in the femoral neck. The athletes were followed for 1 year and their BMD stayed the same, which is positive. The researchers pointed to their previous interventions of increasing vitamin D & calcium intake and including weight training as a reason for the maintenance of BMD. This provides evidence that a good nutrition and training intervention can help maintain bone strength.

Another study in elite male endurance athletes showed that LEA resulted in low testosterone (although not clinically low) however it did not result in any differences in BMD compared to those with normal testosterone levels. There seems to be a caloric value threshold before we start to see negative health and bone effects. Interestingly, it seems as though women are more sensitive to changes in EA, where we see significant and detrimental effects in heath and bone when their EA reaches 30 kcal/kgFFM/day or below. There is evidence that this occurs at levels of 20-25 kcal/kgFFM/day in a male athlete, although more research is needed to confirm this. This study suggested that because they investigated athletes at ~30kcal/kgFFM/day that this was not enough of a deficit to result in decreased BMD. However, this does not mean you can neglect your nutrition planning because even though their BMD did not change, those with low testosterone had 4.5x more risk of sustaining a stress fracture and had 4.5x more missed training days due to injury.

Main Take-Away:
In elite endurance athletes, 40% of males were found to have LEA. Even temporary low EA increases bone breakdown and decreases bone building, and chronic low EA has long lasting effects on bone health plus many more effects such as mental health and performance to name a few. Therefore, it is essential to stay on top of your nutrition as a part of stress fracture/injury risk reduction.

1. Negative energy balance and testosterone: studies show low testosterone results in 4.5x higher risk of bone injury and had 4.5x more missed training days due to injury
2. NFL players and vitamin D: In NFL players, low circulating vitamin D levels correlated with increased risk of core and lower muscle injuries; players with 1+ fractures had higher rates of inadequate levels of circulating vitamin D.
3. Military recruits with lower serum Vitamin D- correlated with higher risk of fractures

References:
Viner RT, Harris M, Berning JR, Meyer NL. Energy availability and dietary patterns of adult make and female competitive cyclists with lower than expected bone mineral density. International Journal of Sports Nutrition and Exercise Metabolism. 2015. 25, 594-602.

Ruohola JP, Laaksi I, Ylikomi T, Haataja R, Mattila VM, Sahi T, Tuohimaa P, Pihlajamaki H. Association between serum 20(OH)D concentration and bone stress fractures in Finnish young men. Journal of Bone and Mineral Research. 2006. 21, 1483-1488.

Heikura IA, Uuitalo ALT, Stellingwerff T, Bergland D, Mero AA, Burke LM. 2017. Low energy availability is difficult to assess but outcomes have a large impact on bone injury rates in elite distance athletes. International Journal of Sport Nutrition and Exercise Metabolism.

keto 1

If you have been following along in my past articles, you saw the evidence for whether or not a keto diet is beneficial for endurance athletes. However, I wanted to also share my thoughts and some research on the keto diet for my non-athlete readers. In this article I will discuss why keto may, or may not, be a good choice for you.

 First off, I want to say that keto is likely not meant to be a life-time eating style.

Typically for weight loss, keto could be used for 2-4 months and then one could switch into a long term maintenance phase where you are including healthy carbohydrates.

Secondly there are some warnings that come with the keto diet. Our brains and hearts run exclusively on carbohydrates and when we severely restrict carbs, our body needs to switch to the use of ketones for fuel instead. There is a 3-4 day period of “brain fog” when you initially switch to a keto diet, where your ability to think is reduced. Not to mention food selection is quite limited and your social life may take a hit due to your restrictions. Plus, fair warning, your breath will smell bad too!

There are risks!

Very close monitoring is required for implementing a keto diet (especially to assess if keto would be a benefit to you). You also have to have a solid plan for transitioning into a regular diet, which should also be lead by a dietitian or qualified health care professional. The latter is quite important. This is because when you starve yourself of carbohydrates and then suddenly reintroduce a large load of carbohydrates, the body switches to an anabolic (or build up) mode and causes increased insulin, increased uptake of carbohydrates into the cells, increased utilization of those carbohydrates, all which increases the uptake and use of potassium, magnesium, phosphate, thiamine and increased sodium and water retention. The sudden changes in these electrolytes and vitamins can cause serious issues that can be as severe as a heart attack. AKA you can not have a cheat day in a keto diet and have yourself a big old piece of cake.

iron sources

Keto & weight loss

Most of the research as a whole shows that you MAY lose more weight on a keto diet vs. regular diet.  However, when studies include body composition analysis they show that on average keto leads to more overall weight loss, but the amount of fat lost is the same. This means that keto diets lead to more muscle mass loss compared to a traditional diet.

Therefore, you may see a better outcome when you step on the scale but it may have less desirable body composition changes.

 The main reason for this finding is that you have to have a moderate protein intake while on a keto diet because protein can be used in a process called gluconeogenesis, where amino acids are (inefficiently) used to make glucose, thus keeping you out of ketosis, where as a traditional weight loss diet will be higher in protein to support the muscle mass retention. Other reasons could also include you can not have dairy, which has been shown to be an important food group to stimulate weight loss and muscle mass retention due to its leucine content.

It is also important to note that resistance exercise is a VERY powerful stimulus of muscle protein synthesis and muscle retention during weight loss, and regardless of diet should be included in your weight loss plan.

There may be benefits too

Keto may work for certain people. For instance, people who are on a keto diet often feel more satisfied with their diets. This is likely because higher fat foods are often pleasurable foods and provide flavour and mouth-feel to food (ie cheese, who doesn’t want to eat a brick of cheese every day!). Johnstone et al. (2008) conducted a study where participants were able to eat ad libitum (ie no restrictions or standards for caloric consumption) and participants were assigned to a keto group or a moderate carbohydrate group. They found that people on a keto diet felt less hungry, and lead to them eating less than compared to a moderate carbohydrate diet.

To my surprise, keto does seem to have a beneficial effect on decreasing blood glucose and HbA1c levels, decrease triglyceride levels, LDL cholesterol, and may increase HDL cholesterol levels. One thing I think is important to remember here is that in most cases, healthy dietary changes (ie more vegetables, fibre, less processed carbohydrates and sweets etc.), decreasing alcohol consumption, and increasing exercise can do the same for you, without doing something as intense or dramatic as a keto diet.

 Take home:

My personal and professional opinion on this is that I would first have someone try a to make healthy diet changes which would include consuming good sources of carbohydrates such as beans, lentils and whole grains before trying a keto diet. Keto in my mind is a last ditch effort if no other dietary interventions have worked.

Summary:

  • Keto diets can be somewhat dangerous and should be eased into and out of with the help of a qualified health care professional
  • Keto diets sometimes result in more weight loss but fat loss is comparable to typical diet
  • There must be a caloric restriction to create weight loss, no different than a regular diet
  • Keto may help keep you full and more satisfied with the diet and may help you adhere to the diet plan
  • Keto does seem to have beneficial therapeutic effects for type 2 diabetes, pre-diabetes and on blood lipid profiles (but so does healthy diet/exercise)
  • Ultimately the diet needs to be something you can follow and stick to before transitioning to your maintenance phase, if that’s keto, great!
  • Bottom line: Try traditional approaches first, if that is not successful, you could consider the keto diet for the short term and transition into a healthy diet intervention for maintenance

I hope you found this helpful, this is not a full list of keto uses and I did not list all the pros and cons for you, as I wanted to keep this conversation relatively short. If you have any further questions about dietary interventions for building a healthier you, please feel free to come in for a visit. To learn more about me, you can find my bio here.  

Reference:

Johnstone AM, Horgan GW, Murison SD, Bremner DM, Lobley GE. 2008. Effects of a high-protein diet on hunger, appetite and weight loss in obese men feeding ad libitum. Am J Clin Nutr. 87, 44–55.

sport - couple running

Are you a constant sufferer of stress related bone injuries? An endurance athlete? Female?

There are many different contributing factors of stress fractures in endurance athletes. Overcoming these challenges and working toward the prevention of these injuries is so important in order to continue with our training and competition schedule. In this article ,I will discuss why female endurance runners are more susceptible to these injuries along with some modifiable risk factors (i.e. nutrition interventions) that can be manipulated to reduce your risk of suffering one!

(Men, I did not forget about you. Stay tuned for an article on stress fractures in male endurance athletes!)

Possible Reasons for Stress Fractures

There are many endurance athlete-specific reasons why stress fractures may occur. One reason for this is the fact that distance running has a high metabolic demand. It costs a lot of energy to run fast for long periods of time and thus increases our need for a higher caloric intake. This can put us at risk if we are inadvertently under consuming calories. Inadequate food intake including both overall energy and micronutrient intake, can play a role in increasing our risk of fractures.

Excessive negative energy balance aside, runners seem to be especially at risk compared to other endurance athletes who also consume lots of calories. Although running does indeed increase bone mineral density (bone strength) with the proper balance of training and recovery, the repetitive nature of high-volume running often leads to the athletes not taking adequate rest days and/or programming in periodized reduced training weeks. This can lead to insufficient recovery and healing of the bone in between bouts of stress and therefore not enough time for the bone to adapt and become stronger. I would refer you to my colleagues, Dr. Sean and Kayla Ng, at the clinic to find out more about how to structure your training schedule.

Version 3 On top of inadvertent negative energy balances and insufficient recovery, some endurance athletes neglect the inclusion of a strength program into their training schedule. Lifting will act as a stimulus to increase bone mineral density. Not only this, but strength training can also aid in enhancing hours muscles ability to direct forces optimally through bones (i.e. compressive vs. sheer forces). For more on this, again I would encourage you to discuss this with my colleagues Dr. Sean and Kayla Ng.

Another risk factor is related to how in some circles, runners are often pressured to fit into the very thin and light body category. First off, low BMI or low weight in itself can be correlated with low bone mineral density. In addition, if that low weight is combined with weight loss efforts and low energy intake, this can wreak havoc on your bone health due to hormonal changes (i.e. decreased estrogen production) and resulting menstrual dysfunction (which can act as an early sign that your are consuming insufficient calories).

BUT, all is not lost!  There is a lot we can do to overcome our bone health challenges. Nutrition, for one, is an easily modifiable risk factor that can have positive outcomes for our bone health.

Nutrition & Bone Related Injuries

To put the need for proper nutrition in maintaining bone health in perspective, here are the results of 3 interesting and very applicable studies on the topic:

  1. Negative energy balance and estrogen: Low energy availability, which is the amount of energy left over after exercise for normal physiological function expressed in calories/kg fat free mass, decreases estrogen levels. This results in a 4x greater risk of bone injury compared to those who have adequate energy availability.
  2. Insufficient calcium: Low calcium intake (800mg) resulted in 6x more risk for bone injury compared to high calcium (1500mg).
  3. NFL players and Vitamin D: In NFL male players, players with 1+ fractures had higher rates of inadequate levels of circulating Vitamin D.

Practical Applications:

So, here’s what you can do:

  1. Make sure nutrition intake closely matches energy demand of sport & daily life.
  2. Consume enough bone building materials (i.e. calcium, vitamin D, and magnesium)
  3. Weight loss tactics should be introduced at appropriate times (likely in the low training/off season) to reduce risk of injury close to race season.

I hope these statistics and general tips reinforce how important nutrition planning is for endurance female athletes. If you still have questions or need guidance on planning for your race season, come visit me at the clinic!  You can check out more about me on my profile HERE.

References:

Tenforde AS et al., 2016. Association of the female athlete triad risk assessment stratification to the development of bone stress injuries in collegiate athletes. The American Journal od Sports Medicine 45(2), 302-310.

Heikura IA, Uuitalo ALT, Stellingwerff T, Bergland D, Mero AA, Burke LM. 2017. Low energy availability is difficult to assess but outcomes have a large impact on bone injury rates in elite distance athletes. International Journal of Sport Nutrition and Exercise Metabolism.

Barrack et al., 2014. Higher incidences of bone stress injuries with increasing female athlete triad-related risk factors. The American Journal of Sports Medicine. 42(4). 949-958.

Papageorgiu M, Dolan E, Elliot-Sale KJ, Sale C. 2018. Reduced energy availability: implications for bone health in physically active populations. Eur J Nutr. 57:847-859.

Maroon JC, Mathyssek CM, Bost JW, Amos A, Winkelman R, Yates AP, Duca MA, Norwig. 2015. Vitamin D profile in National Football League players.

keto 1

By: Steph Boville MSc, RD

Welcome to the third part of the discussion on if ketogenic diets are beneficial for endurance athletes.

In our first article we discussed the fuels we use during exercise, and especially intense endurance exercise. To summarize we learned that exercise at or around 75-85% VO2max is largely relying on carbohydrates for our fuel source.  Carbs breakdown is simply more efficient and and they can be more quickly broken down compared to fat. We also learned that bursts of intense exercise (ie running up a hill) will increase that reliance on carbs, ATP and CP over fat oxidation.

In the second article we learned that ketogenic diets do in fact increase fat oxidation during exercise but that it also comes with a cost!

The costs include suppressing your ability to metabolize carbohydrates, decrease training response, decrease ability to work at maximal effort and decrease running economy. In general, most studies find that performance is reduced with ketogenic diets in endurance athletes.  However some athletes do respond well, and there may be some sports (week long treks) that may benefit from being keto adaptation.

In this last article we will dive into whether or not ketone diester supplementation along with traditionally high carbohydrate diets can be helpful for performance in endurance athletes. Does it help to tap into the best of both worlds? Let’s look at the research!

 Study 1: Can ketone supplement help acutely during a cycling TT?

The theory revolves around this question: Can an athlete can ingest a ketone supplement that will force that individual into a “ketogenic state” without having a high fat, low carb diet?  With the ketone supplement absorbed in the blood stream, the body, in theory, will be forced to metabolize it without having to go high fat, low carb.

Take for instance this study by Leckey et al. (2017).  In the study, 11 elite cyclists complete a 31.17km time trial that simulated the 2017 Bergen World Championship time trial course. They had optimal race nutrition strategies (high carbohydrate) prior to the trial and completed a placebo trial and a ketone diester trial. The ketone diester trial resulted in side effects for most athletes ranging from such severe dizziness, nausea and vomiting that one participant had to dropping out, to moderate-mild nausea, reflux or minor discomfort.  Not good!

All participants completed the time trial faster and achieved higher power output in the placebo trial compared to the ketone diester trial. Further investigation is needed as these findings could have been a result of gastrointestinal discomfort. Fat and carbohydrate oxidation rates were not measured and therefore we cannot explain what happened metabolically but due to the large amounts of ketones found in the urine, the authors speculated that the ketones were not used for energy production.

Vit D

Study 2: Carbs vs. Carbs + Ketones

To play devils advocate, let’s take a look at another paper.  Cox et al. (2016) conducted a study to show the effects of a carbohydrate + ketone beverage vs carbohydrate alone vs a control on endurance performance in a cross over designed study. They showed that consuming the carbohydrate + ketone beverage increased circulating ketones (no surprise), increased free-fatty acids (no surprise), decreased blood lactate levels, had a glycogen “sparing” effect (maybe good, maybe bad) and showed that about 10-18% of energy production came from ketones during exercise.

This supports other theories and research findings that ketosis inhibits the use of carbohydrates as a fuel source, even if it is available for use, and decreases ability to reach maximal intensity of exercise shown by the reduced blood lactate (the anaerobic by-product of glycolysis). The body likely does this to protect and save the available glucose for the brain, as sugar is its preferred fuel source.  Not good if the goal is to go fast!

We have also discussed why shifting to fat as a major fuel source can decrease our economy and efficiency in a previous article. However, this study found that there was a 2% increase in performance with the carbohydrate + ketones. That being said, the hour steady state ride and 30 minute time trial, there was no carbohydrate intake, which very likely could have increased performance vs the ketone drink prior to exercise as glycogen stores can be limiting after 1h of exercise. Therefore, more testing is necessary to compare the high carbohydrate + ketones vs high carbohydrate + carbohydrates during exercise to determine the efficacy of using a ketone diester supplement.

It would also be interesting to see the impact of long term use of a ketone supplement throughout a periodized training plan that utilizes optimal levels of carb consumption. Would this allow for enhanced fat oxidation while also reaping the benefits of ingesting sufficient carbs?

 Practical Applications:

Based on studies like the ones found above and in my previous articles, in general, the best practice for endurance athletes is to:

  • Continue with a high carbohydrate fuelling regiment compared to the ketogenic diets. This way, when athletes are fuelled with carbohydrates (the fuel used in high intensity endurance athletes) they are more equipped to train harder, longer and reap the benefits from all of their hard work on the road, track or treadmill.
  • Remember you are still burning some fat! Athletes don’t need to be too worried about maxing out their ability to metabolize fats because most athletes have a very active and healthy metabolic system and are very efficient at burning fat as a fuel source. Therefore, you don’t have to risk decreased training and injury due to inadequate carbohydrate intake while training.
  • It is also worth noting that some may benefit from pushing their metabolic systems by doing a fasted run on their easy run days, one where you are not sacrificing quality or volume- but make sure you’re getting those important sessions without issue before you start adding these sessions!

I hope this helps!  If you need more help with this or any other nutritional needs, feel free to give the clinic a call.  You can check out more about me on my profile HERE.

 References:

Leckey JJ, Ross ML, Quod M, Hawley JA, Burke LM. (2017) Ketone diester ingestion impairs time-trial performance in professional cyclists. Front. Physiol. 8 (806) 1-10.

Cox PJ, Kirk T, Ashmore T, Willerton K, Evans R, Smith A, Murray AJ, Stubbs B, West J, McLure SW, King MT, Dodd MS, Holloway C, Neubauer S, Drawer S, Veech RL, Griffin JL & Clarke K (2016). Nutritional ketosis alters fuel preference and thereby endurance performance in athletes. Cell Metab 24, 256–268.

keto 1

Welcome to part 2 of the my exploration of very low carb diets for endurance athletes.  My last article provided the basis for understanding this article as it explored how and when our body choses to use fat vs. carbs.  Check it out here.

In this article, I will now explore (1) do low carb diets actually enhance fat metabolism and (2) does that actually makes us faster.

Does VLCD increase fat burning capacity?

Short answer, yes, the body is forced to increase fat use to support the energy needs during exercise. Research clearly shows that after adapting to a keto diet for as little as 3 weeks results in significantly elevated rates of fat oxidation (0.6g/min to 1.5g/min) during exercise. Fat oxidation at moderate intensities (65% VO2max) in elite ultra-endurance athletes on a keto diet contributed 88% of the fuel for exercise verses 56% in athletes consuming high carbohydrate diets. Now, if we remember what we discussed in the last article, we learned that as we increase intensity we increase the amount of carbohydrates burned. This begs the question “will those high fat oxidation rates continue at intense ecercise (80% VO2max)?”. Another study investigated the fuel usage of elite race walkers at 80% VO2max, and they too found that fat oxidation was elevated to the same levels as previous research (1.5g/min).

low carb

Research Outcomes of VLCD and Performance:

The more important question in my mind (and likely yours as well) is “well that is fine and dandy- my body will burn more fat, but what will happen to my performance?!”. We will review some key research studies that have looked at fat adaption diets (high fat diets for 3-7days), keto diets and their effect on performance. The majority of high fat diet adaptation and keto diets find that performance decreased and a handful found they had no-statistically significant effect. Only two articles find a performance benefit.

Keto, Training and Performance

Louise Burke et al. (2017) conducted a large study investigating the effects of a keto diet, chronically high carbohydrate diet or periodised carbohydrate diet on race performance of elite race walkers after a 3 week intervention and training camp. Athletes on the keto diet perceived the training to be significantly more difficult and experienced an inability to complete the exercise training sessions planned. This is a very important point because if an athlete cannot train as hard as they could they won’t see much improvement in their sport.

After the 3 weeks of intense training, the keto group had higher fat oxidation compared to the two high carbohydrate groups. All groups had significant increases in their maximal oxygen uptake (VO2max) as a result of the training. As we discussed in the previous article, burning fat is less efficient and this study clearly demonstrated that at all competition race speeds there was significantly more oxygen used in the keto group and there was no change in the fraction of VO2max at various speeds. The high carbohydrate and periodised carbohydrate groups used less oxygen and were able to keep the same pace at lower fraction of VO2max. In plain English, the two carbohydrate groups improved their running economy and efficiency with the training where the keto group did not reap the benefits of the training because the cost of burning fat is so high.

Lastly, this study compared pre and post training performance walk times in a real 10km race. They found that both carbohydrate groups had a reduction in their time by 5-6% (on average 190s and 124s faster for high carbohydrate and periodised carbohydrate group). There was no improvement in the keto group and on average their times were 23s slower. There was a wide variability in performance for the keto group, ranging from 162s faster to 208s slower, meaning that keto worked for some individuals but not others.

High Fat Diet With Carbohydrate Loading

What if we don’t go into ketosis and we use a fat adaptation strategy + carbohydrate load, best of both worlds right? Havemann et al. (2006) showed that when elite cyclists consumed a high fat diet (68%) for 6 days with 1 day of carbohydrate loading that there was no significant difference in time to complete a 100km simulated bike race compared to a traditional high carbohydrate diet. However, if we look at the time to completion, we find that the high carbohydrate trial was completed on average 3 minutes 44 seconds faster (likely significant in the real world), leading us to believe that on average high carbohydrate diet may be superior to high fat diets. Again, 3 out of 8 racers on the high fat diet did improve their time compared to high carbohydrate diet, demonstrating that there may be some athletes who may respond well to a high fat diet.

More importantly, this research included 1km sprints throughout the ride to simulate a race like situation and found that the power output was significantly lower in the high fat diet group which lead to slower sprint times. Despite having lower power output in the high fat trial, they perceived they were working as hard as they were in the high carbohydrate trial. There was no difference in muscle recruitment during the sprints, meaning the high fat trial worked just as hard as the carbohydrate trial but did not achieve the same results in the sprint performance. The researchers thought that the high fat diet + a carbohydrate loading period would result in glycogen sparing due to increased reliance on fat for fuel, thus improving sprint times as sprinting relies on glucose to provide fuel. This was not the case and it is possible that high fat/fat adaptation diets reduce the ability to effectively burn carbohydrates.

Summary

  • VLCD do result in higher rates of fat oxidation during exercise
  • VLCD may reduce response to training
  • VLCD decreases economy in elite athletes
  • VLCD decreases ability to work at maximal effort which is important when there is change in work intensity- ie running up a hill, breaking away from the pack
  • Most studies show that on average VLCD negatively affect performance in endurance athletes, however there are some that may respond well
  • Remember that VLCD are not the same as training fasted or temporarily low carb diets to train your body to use fat more effectively, as this is an effective training method

In my final article in this series, I will explore the roll of supplements, the keto diet, and how that relates to athletic performance.

References:

Volek JS, Noakes T, Phinney SD. Rethinking fat as a fuel for endurance exercise. Eur J Sport Sci. 2015;15(1):13- 20.

Volek JS, Freidenreich DJ, Saenz C, Kunces LJ, Creighton BC, Bartley JM, Davitt PM, Munoz CX, Anderson JM, Maresh CM, Lee EC, Schuenke MD, Aerni G, Kraemer WJ, Phinney SD. Metabolic Characteristics of keto-adapted ultra –endurance runners. Metabolism. 2016;65(3):100-10.

Burke LM, Ross ML, Garvican-Lewis LA, Welvaert M, Heikura IA, Forbes SG, Mirtschin JG, Cato LE, Strobel N, Sharma AP, Hawley JA. Low carbohydrate, high fat diet impairs exercise economy and negates the performance benefit from intensified training in elite race walkers. J. Physiol. 2017;595(9):2785-2807.

Havemann L, West SJ, Goedecke JH, Macdonald IA, Gobson ASC, Noakes TD, Lambert EV. Fat adaptation followed by carbohydrate loading compromises high intensity sprint performance. J. Appl. Physiol. 2006;100: 194-202.

Leckey JJ, Ross ML, Quod M, Hawley JA, Burke LM. Ketone diester ingestion impairs time-trial performance in professional cyclists. Front. Physiol. 2017;8(806).

53650544 - foods high in carbohydrate on rustic wooden background. top view

There has been a burst of social media hype around the idea of using very low carbohydrate (ketogenic or keto) diets for endurance events. The keto diet usually consists of 5-10% of total kcal (~50g or less) from carbohydrates per day, 75% from fat and 10-20% from protein, although there is no set standard of carbohydrate level. In this article I want to talk about how the body uses energy during exercise before we get into the research.

If we look at the stores of energy in the body, we know that our ability to store carbohydrates as glycogen is limited. We can store carbohydrates in our muscles and liver and the more trained an individual is the more they can store, however it is still limited and can only supply about 1500-2000kcal and muscle glycogen is depleted within 1hour of intense exercise. Fat on the other hand is very calorically dense and we can store 65 000 kcals (could fuel about 20 marathons!) in our adipose (fat) tissue and within the muscle. Fat can supply significantly more energy than carbohydrates without supplementation. This diet is seen as attractive because it promotes the idea that we can max out our capacity to burn fat as a fuel while running, reducing the amount of food or energy we need to take on the run. Therefore, it seems logical to adopt a keto diet, max out our ability to burn fat as a fuel, right? Well let’s look at this topic a little deeper.

low carb

 

Understanding Energy Production During Activity

Our body uses two processed to produce energy in the form of adenoside triphosphate (ATP). The first method is anaerobic (without oxygen) and the second is aerobic (with oxygen). There are 3 energy systems that the body uses depending on a few factors, such as intensity, length of event, and availability of oxygen.

(1) Phosphocreatine System

This system is the quickest way to produce energy and is the first system to turn on to crank out ATP. Let’s say as you are reading this article your fire alarm stated to ring, you would immediately jump up and run out the door. In this fight or flight response you are using mostly the phosphocreatine system. It works by taking the phosphocreatine that is stored in the muscles, and through an enzymatic reaction the phosphate is split off and added to adenosine diphosphate to make ATP. This is a very simple reaction, and the body can use this system for about 8-10 seconds before it’s tapped out. This system can recover; it takes about 4 minutes before the system is ready for another intense bout.

(2) Anaerobic glycolysis

This is the second system to turn on to support energy production. To continue with out analogy from above, after our initial jumping and sprinting for the door, after the 8ish seconds our body tends to rely more heavily on the anaerobic glycolysis system. This system uses carbohydrates (glucose) and through a series of steps breaks down 1 glucose molecule into 2 pyruvate molecules. Without oxygen, this pyruvate can be further broken down into lactate and a hydrogen ion and ATP. This system will last about 1-2 minutes. In repeated sprints, such as hockey shifts, research shows that subsequent sprints rely on anaerobic glycolysis to provide 50% of the energy.

(3) Oxidative phosphorylation (Aerobic system)

This system takes a while to get warmed up and to get going once you start exercising. In untrained individuals, it can take a few minutes for this engine to get running fully, but in elite athletes it can fully turn on within about 30-60seconds. In our analogy above, lets say we lived in the country and we needed to go run to the fire station down the road, after our initial sprint and quick getaway, our aerobic system turns on and produces a majority of the energy needed. This system can last forever; at rest we are aerobically oxidizing mostly fats to provide energy for the body at rest.

The aerobic system can burn carbohydrates, fat and protein depending on availability and intensity. Protein used in very small amounts to provide energy for exercise and we wont discuss it further here. I want to discuss the differences between fat and carbohydrate oxidation.

The classic study from Romijn et al. showed that the fuel sources changed depending on the intensity of exercise. They looked at 25% VO2Max, 65% VO2Max and 85% VO2Max. The found that as intensity increased, so did caloric expenditure and the more intense exercise relied more heavily on carbohydrate use. This is because at higher intensity of exercise the fat breakdown and transport into the mitochondria and oxidation rates are too slow to keep up with the energy demands.

pic

Carbohydrate is also the preferred fuel during intense activity as it provides 5.5% more kcal/L of oxygen compared to fat oxidation, meaning it is a more efficient fuel source. Research shows that elite level marathoners fuel use is 85% carbohydrate and 15% fat oxidation.

One thing to note is, you do not only use one system at a time, your aerobic system is always running in the back ground. Think of these systems like dimmer switches, they can be turned up or turned down depending on the situation. For example, if we take a cyclist who is riding on a flat surface, they have their aerobic system pumping out most of the ATP to cover the cost of their cycling. When they hit a hill, there is an increased demand for ATP. The aerobic system take a little while to adjust, and therefore the anaerobic system has to kick in to provide some quick energy, and that means the phosphocreatine system turns on, and the anaerobic glycolytic system turns on to meet the ATP needs of the body.

Key points:

  • Fat is slower to provide energy, and therefore intensity is lower when using fat as a fuel source
  • Fat is less efficient; it uses more oxygen to produce less ATP
  • High burst of exercise- ie the energy change when cycling or running up a hill is usually covered by anaerobic glycolysis which uses glucose (carbohydrate)
  • Most elite athletes run at high %VO2 and burn a large amount of carbohydrates

References:

Romijn JA, Coyle EF, Sidossis LS, Gastaldelli A, Horowitz JF, Endert E, Wolfe RR. Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. Am J Physiol. 1993;265:E380-E391.

O’Brien MJ, Viguie CA, Mazzeo RS, et al. Carbohydrate dependence during marathon running. Med Sci Sports Exerc. 1993;25:1009–1017. doi: 10.1249/00005768-199309000-00007

Bosch, AN, Goslin BR, Noakes TD, Dennis SC. Physiological differences between black and white runners during a treadmill marathon. Eur J Appl Physiol. 1990;61:68-72.

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