Sunday 10 March 2013

The Breakfast of Champions?




Frequently referred to as the most important meal of the day. But where does it fit into a sports nutrition plan?



You've spent hours training, braving wet weather, dark nights, early mornings, aching legs and – quite possibly – missing toe nails.

After all of that effort it really would be a shame not to be in optimal condition come race day, yet lots of people neglect a vital component of pre-race preparation. Breakfast.

There’s an awful lot of (often conflicting) advice around what the right thing to do is when it comes to eating and sporting performance, so it’s quite understandable that you might be a little confused about the best way to approach nutrition. So here I present for you all you need to know about pre-event fuelling.

Do I have to eat?


No. You don’t. However, bear this in mind – if you have the time and opportunity, why would you choose to avoid eating on the very day you plan on undertaking an activity with high energy demands?

It is not essential to eat before taking part in sporting activity, whether it be running, triathlon, swimming, football or whatever sport it is you do. Assuming you eat a diet that includes carbohydrates, your body should have sufficient glycogen stores to fuel around 90 minutes of activity. For running, that should be enough time to complete distances up to and including a 10K run, and perhaps even half marathon for the speedier runners out there.

Once your glycogen stores have been depleted – after ~90 minutes – there are ample stores of both fat and protein to tap into.

However – and this is important – glycogen is the preferred fuel for working muscles and essential for the brain.

The metabolism of both fat and protein can (and do) provide energy to keep you moving, but the mechanism by which they are utilised is less efficient than that of carbohydrate stores.


To illustrate the point, watch:


Now this is a slightly extreme example, although there does seem to be an increase in the popularity of Ironman distance triathlon, so perhaps not as unlikely as you might think. 

Both ladies have significant stores of both muscle and fat, and yet they are literally dropping on their feet. Muscle cramps and a build up of lactic acid are likely to be contributory factors to their struggle to complete the race, but the primary factor it likely to be that fuel simply isn't being supplied rapidly enough to keep either the muscles or brain going, and as a consequence they are struggling to coordinate their movements, losing their balance, falling over and suffering. A lot.


So whilst our bodies do have stores of fuel, they can't be relied upon to keep us going in the absence of carbs/glycogen. 

During the night time fast (also known as sleeping) your stores of liver glycogen are significantly depleted, and there is associated dehydration. The morning meal helps to restock the glycogen and to rehydrate the body, thereby providing energy to meet the demands of activity without further depleting stores.

So do you have to eat before a race? No. But is it recommended that you do? Yes. Especially if you’re likely to be active for more than ninety minutes.

What types of food should I eat?

As to what you should eat, it really depends on the demands of the race. But there are some basic rules to adhere to.

It needs to contain carbohydrates 
As we've already said, carbohydrates are the body's preferred fuel source. The body has some glycogen stores (endogenous carbohydrates) that can be used, but once this is expended you are reliant on a combination of what you eat (exogenous carbohydrates) and other body stores of energy - protein (muscle) and fat. As carbohydrates are more efficiently used, they permit higher intensity activity and longer duration. 

Not all carbohydrates are created equal. They can broadly be divided into two categories - simple and complex. Simple carbohydrates are sugars (either added or intrinsic, that is, found naturally within the food), whilst complex carbohydrates are more commonly known as starches. 

The chemical composition of the simple vs. complex carbohydrates is such that simple carbohydrates are more rapidly metabolised than complex, and therefore are more readily taken up as fuel. Complex carbohydrates take longer to break down, and therefore have a longer lasting effect. Eat a combination of these and you can reap the benefits of both to provide both a rapid and a sustained energy release.


Add some protein 

The protein is optional, but recommended, for three primary reasons. 

Firstly, protein is the most satiating of the macronutrients, that is, it helps you to feel full. Now, you don't want to be going into a race feeling like you're fit to bursting, but nor do you want to get part way through your race and feel ravenous. So eating some protein as part of your pre-race breakfast can stave of grumbly tums and hunger pangs. 


Secondly, protein helps to control the rate at which carbohydrates are absorbed. Proteins slow gastric transit (the rate at which things move through your gastrointestinal system) and therefore have the effect of lowering glycaemic load - the rate of uptake of the carbs into your system. 


Thirdly, protein contains energy. And an exogenous (originating from outside the system, in this case, the body) source of energy can help to spare/postpone energy being taken from body stores. 

So three good reasons for including protein. 


What are your choices?





Avoid fat


Whilst fat can provide you with a decent amount of exogenous energy, it is digested more slowly than either carbohydrates or protein, to the point at which is can cause problems when you are racing. You really don't want food lingering within your GI system whilst your racing - it's likely to cause cramping, nausea, bloating and diarrhoea. 
So small amounts of fat are permissible, but a particularly fatty meal is to be avoided. Leave the full English fry-up for another day. 


Avoid fibre


The ability of the gut to cope with fibre various widely from person to person. Fibre is renowned for contributing to GI problems during sporting activity. For more information, see my previous post on Runner's Tummy


Drink!


A small degree of dehydration occurs over night. The American College of Sports Medicine (ACSM) recommend that 400-600ml of fluids be consumed around two hours before an event to optimise hydration status. 


How much should I eat?

The amount of food you need very much depends on the duration of your race and the intensity with which you plan on completing it. If you want to go further or go faster there are increased energy demands that you need to meet, so you need to eat more for a longer distance/faster race. 

The general recommendation for the pre-race meal is to eat 2-4g of carbohydrates per kilogram of body weight, aiming for the higher end of the spectrum for longer events. 




Remember though: the more food you eat, the longer you need to allow for digestion if you want to avoid GI distress - as already said, you really don't want a stomach full of food when the klaxon goes off!


Ideally you'll eat 2-4 hours before the race begins. For most races (typically with morning starts) this would mean being up pretty early!


Now, not everyone likes eating breakfast, perhaps even less so if it's very early in the morning. So you have options: 



  • Split the meal into two/three smaller snacks. Have the complex carbs first, then an hour or two later have a snack based more on simple carbohydrates. 
  • If you can't face eating four hours before a race, when you do eat, aim for the lower end of the range for your body weight (2g/kg body weight) and increase the ratio of simple carbs which are more easily digested. As you'll now be eating less, remember to fuel during the event, if the distance/duration warrants it (90 minutes and above).
  • If you really can't face breakfast early in the morning, liquid carbs are a good option. They require less digestion so can help if you get pre-race nerves/queasiness or are just not used to having breakfast. Something like a juice or a smoothie is a good option, as are some of proprietary sports drinks. 

So what does that all mean?


It's fairly simple - eat breakfast! 
  • Focus on carbohydrate rich foods. 
  • Have some protein.
  • Avoid too much fat and fibre. 
  • Rehydrate!
  • Don't fret too much over getting the numbers spot on. Unless you're a top level athlete, it's unlikely to make a huge difference to your performance. 
  • Finally - and this one is important - NEVER try anything new on race day. 



Carbohydrate and protein content of common breakfast foods



3 comments:

  1. I'm intrigued that you classify foods by simple/complex carbs. As I understand it, isn't it more relevant for the endurance runner to understand the relative glycemic index? Or am I missing thepoint? (Again.)

    ReplyDelete
    Replies
    1. Hi Mike,
      You're not missing the point at all! Glycaemic index is commonly used in sports nutrition, but I've focused on simple vs. complex carbohydrates because they are more reliable (in my view) than the glycaemic index. The classification of simple/complex carbohydrates is based on the chemical structure of the food. Whilst there are exceptions, it is generally the case that simple carbs are also high GI, and complex are lower GI.
      Whilst the glycaemic index is useful, there are significant flaws in applying it to human nutrition. Briefly, the GI of foods differs depending on variety (i.e. different types of apple have different GI values), how they are cooked, stored, processed, and how ripe they are. Foods are rarely eaten in isolation, so the combination of foods affects the glycaemic load (GL) of the meal. It is also the case that the body's glycaemic response to food varies depending on age, ethnicity and efficiency of the insulin response.
      As you can see, GI is far more complicated than it may first appear, and certainly more so than most proponents of it will let on. There's no reason not to take it into account, but do be aware that it isn't the be all and end all of sports nutrition.

      Delete
  2. Thanks. That's very clear. :)

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