Carb-loading basics

By Rachel Hannah, RD, DIP. Sports Nutrition IOC

There are a lot of myths around carb loading. That confusion mixed with pre-race nerves, and you’ve got a recipe for a tummy disaster. But carb loading is actually pretty straightforward. There are a few key numbers and rules to follow so that you’ll have all the energy you need to start your quest for that big marathon breakthrough.

What is this “carb loading” I keep hearing about?

First, let’s start with removing the shroud of mystery around the carb load. What the heck is it, and why do marathon runners do it?

Simply put, to carb load is to put a bigger emphasis on getting in an increased ratio of carbohydrates in a couple of crucial days leading up to a big distance race of over about two hours, like a half-marathon for most, and certainly a marathon. The reason for doing this is to make sure your body is full stocked with something called glycogen, which is the energy used by your muscles to fire during your run.

Glycogen is your storage form of carbohydrates and the body can only store up to a certain amount, making fuelling throughout a Marathon distance race very important. Ever heard of the infamous “wall” runners hit when the marathon gets really tough? That wall goes up typically when your body is depleted of glycogen. It’s why races put Gatorade on the course, and its why runners stuff their faces with pancakes the day before the race.

Pancakes… sounds like fun! But how do you get carb loading just right?

Make a Plan

When working with athletes of all ability levels or going into my own marathons, the first thing I do is make a carb loading plan. It’s not necessarily a menu of exactly what to eat, but more of an outline of when to start the load, examples of great food options, and specific numbers that are easy to calculate so that its clear just how many carbs are needed each day before the big race.

Here’s what it looks like:

You should start your carb load 36-48 hours before race morning. So, if the marathon is on a Sunday, begin focusing on carb-rich foods on Friday at breakfast. You’ll hear about athletes going on a “carb depletion” diet for the week leading up to the marathon, starving themselves of glycogen so that, supposedly, their body will horde the sugars thrown at it during the carb load. There are conflicting studies on this strategy, and the science is leading towards saying it produces a negative outcome in most situations, so just eat normally for the period leading up to the carb load.

Keep your calorie intake relatively normal

A common myth is that you should stuff your face during the carb load. This may cause some serious tummy issues and water retention, so instead, just focus on getting the percentage of carbs within each meal and snack to overwhelm the ratio to protein and fat. Fat intake should be kept low (<20% of calories) during the carb load, but you should focus on getting a consistent amount of protein at every meal and snack like you normally would.

Because you’ve reduced you the amount of exercise during the taper, if you maintain your peak season diet, you should be coming in pretty well stocked up on calories.

Focus on the Math

Here’s the magical formula to follow during the carb load:

8-12 g/kg of your body weight of carbs per 24 hours.

So, if you weigh 65 kg (or just over 140 lb.) you should be consuming about the middle range of that formula, meaning 650 g of carbs in a day. A small banana has 14 g of carbs, so you’ll have your work cut out for you to get them all in without starting to hate certain go-to snacks. You’re going to have to find simple ways to make sure you get that amount all in.

Eat what you love

Stick with things you enjoy eating, and I mean really enjoy. Carb loading is the opposite of what you typically would eat to stay healthy. I also need to add carbs that I wouldn’t normally add during the load. This may sound ridiculous, but I will even bring packets of jam or honey with me, and smear them on things like crackers and bread if I feel I’m not hitting my goal carb number for the day.

Use a fitness tracker

Keeping track of all those carbs can be daunting. I recommend either doing the math in advance and making a meal plan for that 48 hours (think of it as fun; you get to eat waffles and maple syrup for dinner!) or use a basic calorie counting app. I rely pretty heavily on MyFitnessPal, a free and fairly detailed nutrition tracking app you can get on your phone that will do the math for you.

Beware of fibre

Crushing carbs can be fun, but you have to be mindful of those with loads of fibre. You’ll want to focus on simple carbs for this crucial 36-48-hour period. You don’t want to pack your guts with fibre before heading to the start line, for obvious reasons.

On the eve of the race, switch to liquid carbs, like fruit juices or sports drink, in order to keep your stomach in check while continuing to get those glycogen stores stocked. Choosing the sports drink you will use during your race is a good idea the night before.
Spread Your Snacking Out

Aim to eat about five or six times per day, spread out, particularly if you have pre-race nerves and your digestion is slowed down. Focus on eating every three-four hours, but feel free to snack a bit in between and take in fluid.

See the carb load as the final fun workout

Just like training, view the carb load as a sort of food workout. Stick to your numbers, stay focused and see it as the final building block in order to have a big breakthrough in your goal race.

Rachel Hannah is a Pan Am Games medallist in the marathon and a registered dietitian.  Learn more about her HERE or book online HERE. 

Caffeinated Gum and Athletic Performance

Caffeine is one of the better researched and most effective ergogenic aides (performance enhancing) out there. Research shows that caffeine can be beneficial in many sports, from sprints or power events to team sports and endurance activities. Interestingly enough, a lot of sport nutrition principles originally were studied in military personnel due to their high activity level and training intensity and then applied to sports. Caffeinated gum has been researched for military purposes in order keep the solders awake and alert in the field. In this article, we will be looking at the use of caffeinated gum to boost sport performance.  

What does caffeine do? 

There are many different theories of how caffeine exerts its affects on athletic performance. Firstly, caffeine blocks the adenosine receptors in the central nervous system. This makes us feel more alert, decreases our perception of how hard we are working and can even decrease our perception of pain. Research also shows that caffeine can have a direct effect on the muscle, where it can enhance the motor unit recruitment and coupling reactions which increases the force produced by the muscle units. It may also have an effect on the calcium release in the muscle which is needed for muscle contraction. 

 Dose

A caffeine dose of 3-6mg/kg body mass is effective for most athletes t
o see a boost in performance. Therefore, a 60kg individual would need 180-360mg of caffeine. It is theorized that regular caffeine users (coffee/tea drinker) may need the higher end of that range as they may be less sensitive to the effects of caffeine. 

Benefits of caffeine gum?

Most research studies look at the effect of caffeine capsules taken before exercise. The caffeine levels from the capsules peak within 45-60 minutes of ingestion. Chewing the gum will allow for quicker absorption (5-10 minutes) compared to a capsule, as it is partially absorbed in the mouth. If you were to try and get 300mg of caffeine through drinking a coffee, you would have to consume a Grande (16oz) Starbucks Pikes Place close to your race. That much coffee right before a race or event may not sit well with some people or may lead to some unplanned pit stops along the way. Therefore, it may be beneficial to chew gum verses drink a coffee to get your caffeine fix! 

What Does the Research Say? 

Let’s take a look at some new research! I have reviewed two studies published this year where investigators looked at the efficacy of caffeinated gum in rugby and endurance runners. 

Rugby Players

Ranchordas et al. (2019) recruited 17 university level male rugby players to participate in the study. This group was instructed to consume 200mg of caffeinated gum, providing 2.3mg/kg on average. After a warm up, they performed a battery of rugby specific testing which included countermovement jump test for power, Illinois agility test which measured the athlete’s ability to change direction in a 6x30m repeated sprint and a yoyo IR2 test which is like the beep test where they increase running speed to complete 2x20m runs. They found that the caffeinated gum improved jump height by 3.6%, and significantly lowered fatigue index compared to placebo. They also found that the caffeine group had prolonged preservation of energy levels during sprinting, allowing them to cover significantly more distance in the endurance sprint test (426m vs 372m or 14.5% improvement). They did not observe any improvements in agility. One last interesting note was that there were no adverse effects of the caffeinated gum. This is a positive because it may be an easier option for caffeine intake for those who have negative GI effects from coffee before a game or athletic event.

Endurance Runners 

A study by Dittrich et al. (2019) looked at the effect of caffeinated gum on the performance of 12 trained male endurance runners. Runners chewed 3 pieces of gum equaling 300mg of caffeine (~4mg/kg) after their warm up. Participants were asked to run until exhaustion at a predetermined speed of half way between their VO_2max  and their first lactate threshold. After their run, they tested their maximum voluntary muscle contraction. Caffeine intake resulted in significantly increased time to exhaustion (or exercise tolerance) by 18% resulting in significantly larger distance covered (1.9km). The maximum voluntary muscle contraction and peak twitch both decreased from the pre-run measures, however they did not find any significant benefit of the caffeine compared to the placebo. The fact that the caffeine trial ran a further distance may have resulted in no differences in the neuromuscular function, as their muscles would have been more fatigued from the longer run. However, this is just speculation and more research should be done in this area to confirm this theory. 

Recap 

• Caffeine intake can help increase alertness, decrease perceived exertion, possibly help with muscle force production and contraction  
• Dose of 3-6mg/kg body mass is enough to produce effects on performance 
• Caffeine can increase exercise tolerance, running distance and jump height 
• Chewing caffeinated gum is an easy way to quickly get a caffeine boost prior to your race without chugging a few cups of coffee 
• Caffeinated gum doesn’t seem to have adverse effects, so it’s great for people who cannot tolerate coffee before a game or race 

References

Ranchordas MK, Pratt H, Parsons M, Parry A, Boyd C, Lynn A. Effect of caffeinated gum on a battery of rugby-specific tests in trained university-standard male rugby union players. Journal of the International Society of Sports Nutrition. 2019;16(17). https://doi.org/10.1186/s12970-019-0286-7.  

Dittrich N, Serpa MC, Lemos EC, De Lucas RD, Guglielmo LGA. Effects of caffeine chewing gym on exercise tolerance and neuromuscular responses in well trained runners. Journal of Strenght and Conditioning Research. 2019. 00(00)1-7. 

Canada’s NEW Food Guide

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!

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!