Saturday 15 June 2013

Water, water everywhere, but how much should I drink?

Hydration






Hydrating during exercise has received a fair bit of attention of late, with controversy over what, when and how much you should or should not be drinking. A fairly simple truth though is that hydration does have an effect on both health and athletic performance. You just have to get the balance right.

Let’s take a look at some of the basics.

When we exercise our bodies generate heat. It’s essential that our temperature is regulated within a fairly narrow range, or we are at risk of heat injury – commonly known as heat stroke or heat exhaustion.

Heat injury is unpleasant, potentially dangerous and will certainly impair athletic performance.

But it can be avoided.

Sweating is the body’s primary method of cooling and our capacity to cool is therefore in part dependent on our level of hydration – if you don’t have the fluid to lose, your body can’t cool itself. And it’s for this reason that it’s important to maintain an adequate level of hydration when exercising, particularly in warm/hot environmental conditions.

Now, British summers tend to be a little unpredictable. Last year’s summer was rather wet and cold, but the top temperature did peak at over 30C. Data from the Met Office shows that the average UK summer temperature is 18.3C, with temperatures in the south of England nearer 20C. So whilst we may feel constantly bombarded by greyness and drizzle, there is actually a chance that a summer race will be a warm one.

And combining warm conditions with exercise-induced heat present a real risk for heat injury.

So how can you avoid problems with heat? Appropriate gear has an important place, but that’s another story.

A sufficient fluid intake will permit optimal sweating and, therefore, maximise your opportunity for cooling.  

The next – and most important – question, is how much should you drink?

Unfortunately, it’s impossible to provide one-size-fits-all guidelines. The amount of fluid you lose is influenced by several factors, including environmental temperature, humidity, gender, body size and composition, what clothing you wear, how well trained you are, how intense you’re exercising and how acclimatised you are to the heat… You can see why a standard recommendation for everyone isn’t really suitable!

That said, there are some guidelines to assist in working out what you need to be doing. These are based on hydration before, during and after an event.

Before
  • Start the race well hydrated. For most people, normal eating and drinking will be sufficient
  • To assess your level of hydration, look at your urine (it’s not as weird as it sounds!). Urine should be a pale yellow. The darker the urine, the more dehydrated you are. If your pee is the colour of an Oompa Loompa then get some fluids down you! 
  • DO NOT overload on fluids – you’ll probably need to pee mid-race, and excess fluids can be more dangerous than dehydration.
  • 5-7ml per kg of body weight, 2-4 hours before the race starts should be sufficient to be adequately hydrated. Unless you assess yourself to be dehydrated, opt for the lower end of the range to avoid the need for unnecessary toilet breaks.




During
  • You can work out roughly how much fluid you lose during a run by weighing yourself pre and post training. 1ml of fluid weighs 1g, so a 1kg weight loss equates to 1 litre of fluid. Doing this will let you know roughly how much you’re sweating, so you can tailor your fluid intake to match your losses.
  • The general recommendation is to have 400-800ml per hour. Female, slower or lighter runners should aim for the lower end of the range, and heavier/faster runners toward the upper end.
  • Sip drinks rather than gulping – small, frequent sips are ideal.
  • If in doubt, drink to thirst.

After
  • Normal meals and drinks are usually sufficient to rehydrate.
  • Eating salty snacks can replenish lost sodium and also promote drinking.
  • Check your urine colour again. If it’s dark or you go for a long period of time without needing to pee, keep drinking until you produce pale yellow urine.


What should you drink?

There’s been a bit of debate recently about the benefits, or otherwise, or sports drinks. Whilst there is a lack of evidence to back up some of the claims made by the big brands, for the purposes of hydration, a drink that contains water, electrolytes and carbohydrates does tick all of the boxes.

The consumption of electrolytes (such as sodium) and carbohydrates at the same time as fluid has several benefits.

Firstly, when you sweat, you lose not only fluid but also sodium. Low sodium levels are potentially dangerous and can lead to the development of a condition known as hyponatraemia.




The risk of hyponatraemia is a real one, particularly on a hot day. Drinks can be both refreshing and cooling, and if you keep glugging away then there’s a real chance that some sodium dilution will occur. Drinking an isotonic sports drink is a fairly simple solution (no pun intended!), as is the use of electrolyte products such as those provided by Sis, Nuun or High5 (other brands available J ).

If you do want to combine your hydration strategy with your fuelling strategy, then this can be achieved by using a sports drink. There are lots of brands available – an easy option that ensures you get a decent formulation, convenience and (usually) a palatable drink.

There’s also the option of making your own sports drink. This is usually a much cheaper approach, and can be tailored to your own preferences. Sports drinks are essentially water, salt and sugar, so using those basic ingredients you can make yourself a perfectly serviceable sports drink.

Shop-bought sports drinks typically contain: 6-8% carbohydrates and 200-700mg sodium (0.5 - 1.8g salt) per litre, and this is what you want to replicate in a homemade version.




Being honest, option number one isn’t particularly palatable. The lack of flavour to override the salt can make it difficult to drink, so adding a cordial of your choice is advisable.

An alternative is to use fruit juice.



It really is that simple. You can use whatever juice you like and the benefit here is that there is a blend of different sugars, usually glucose and fructose, which can maximise the uptake of energy into your body.

A word of warning though – anything you plan to do during a race should be tried and tested before race day. The workings of your gut are very much disturbed during prolonged activity, and gastrointestinal discomfort is common amongst endurance athletes. Don’t let months of training be scuppered by experimenting with a new sports drink on race day!

So that’s the basics.

To sum up: hydration is important to sporting performance, which is impaired by both under and over-drinking, both of which have their own risks. A little bit of pre-planning goes a long way in working out what your own needs are, and drinks containing sodium can prevent dehydration and hyponatraemia. And finally, whilst it may seem unlikely, if/when the British summer does delivers on the longed-for warm weather, it’s particularly important to get your hydration strategy right.

Apply the Goldilocks principle: not too little, not too much. You want to get it just right.




Saturday 4 May 2013

Adventures in Flapjackery - Part 1

Flapjacks.

Cheap, easy to make, versatile and (potentially) nutritious, flapjacks are often a go-to snack of choice, particularly for those engaging in sports.

They have the illusion of being a healthy treat - based on oats, it's easy to liken them to a bowl of porridge.
A traditional recipe for flapjacks, however, is loaded with added sugar and fat, and what seems to be a small snack can easily contribute significantly to your daily intake of calories and macronutrients.

Oats are an excellent source of slow-release carbohydrates, being low on the glycaemic index. They are also a useful source of protein and contain a form of soluble fibre that has been demonstrated to lower 'bad' LDL cholesterol.

So all in all, oats are good.

Back to flapjacks though, the added sugar and butter detract somewhat from the virtues of the oats. Whilst I very much hold the view that there is a place for everything in the diet (just so long as it's edible!) and moderation is key, I also enjoy a little bit of experimentation in the kitchen. A little bit of tweaking, some alternate ingredients, and flapjacks can be re-invented in a much more healthy fashion. And if you can make something healthier, then why not?

And to that end, I present some flapjack recipes.

The Recovery Flapjack

Containing a carbohydrate/protein ratio of 2 to 1, these flapjacks are ideal for a post-workout snack. The carbohydrates will replenish depleted glycogen stores, whilst the protein content will assist with muscle repair and synthesis.

They contain no added fats (the fat content comes from the peanut butter), and are much lower in added sugars than traditional flapjacks, as much of the sweetness comes from added fruit.

Allergy information:
This recipe contains peanuts, so is not suitable for nut allergy sufferers.
Use gluten-free oats to make them safe for coeliacs. 
Contains no egg or dairy.

Ingredients

175g crunchy peanut butter
5 tbsp golden syrup/honey
200g porridge oats
1 ripe banana, mashed
75g raisins

Method

1. Grease and line a 20cm square baking pan. Preheat the oven to 180C/Gas 4.
2. Place peanut butter and golden syrup/honey in a saucepan, and heat until melted.
3. Add the remaining ingredients and stir until combined.
4. Press into the prepared pan, and bake for 20-25 minutes (ovens will vary).
5. Leave to cool in the pan for 10 minutes before cutting into 12-16 pieces, depending on desired size.






Pizza Flapjack

A savoury option, because flapjacks don't have to be sweet.

It's a common complaint from people who take part in endurance sports - pretty much all of the shop-bought nutrition products are sweet. Gels, drinks, and bars tend to be based around glucose and are typically flavoured with chocolate, fruits or vanilla. Fair enough, but the sweetness can become cloying. For this reason people turn to alternate strategies, often opting for things like Marmite sandwiches or pork pies. This recipe is inspired by the good ol' pizza. In flapjack format.

This recipe is only marginally higher in fat than traditional flapjacks, but it is still worth bearing in mind that fats can cause gastric discomfort in susceptible people. Try in training and not for the first time on race day, if using as part of a fuelling strategy.

The carbohydrate/protein content is again a 2 to 1 ratio, so useful for recovery as well as general fuelling.
Nutritionally, the tomato puree, grated carrot and courgette provide useful vitamins, whilst the cheese content provides both protein and calcium.

Other vegetables - sweet potatoes, butternut squash, pumpkin, parsnip, etc. can be used as substitutes for the carrot or courgette if liked.

Allergy information:
Contains dairy and egg.
Can be made with gluten free oats. 
Contains no nuts. 

Ingredients

250g porridge oats
150g cheese
1 egg, beaten
1 carrot, grated
1 courgette, grated
50g butter
1 tbsp tomato puree
1 tsp mixed Italian herbs


Method


1. Grease and line a 20cm square baking pan. Preheat the oven to 180C/Gas 4.
2. Place butter, tomato puree, herbs and grated vegetables in a saucepan, and heat until melted.
3. Remove from the heat, and add the remaining ingredients - stir until combined.
4. Press into the prepared pan, and bake for 20-25 minutes (ovens will vary).
5. Leave to cool in the pan for 10 minutes before cutting into 12-16 pieces, depending on desired size.







Warning! Tastebuds will vary - but as far as I'm concerned, these are delicious!

Part 2 coming soon!

Monday 11 March 2013

Breakfast - what to eat!



Following on from my last post exploring the importance of the pre-race breakfast, I was asked to provide some practical examples. 

So here we go!

First off, I'm basing this info on some very typical breakfast foods. Cereals, toast, bagels, etc. The examples are far from exhaustive and there are many other weird and wonderful foods you might eat. Just have a look at the food label to work out the carb content of your food of choice. 

I'll stick with the mundane though, as let's face it, it's more likely than not that you'll be reaching for the tried and tested favourites on race day. 

The idea is this - pick the base of your meal. Toast, a bowl of cereal, etc. Then add a topping of your choice - jam on your toast, honey in your porridge, and so on. Double up if you want to! Raisins and a banana together provide 44g of carbohydrates in a fairly modest amount of food. Finally, add some fluids. Milk on your cereal or as a drink, a glass of juice, or for a big hit of carbs, a milkshake. Mix and match as you choose!





Some examples...

Example 1




The amount of jam used in this example is fairly modest - at ~11g per tablespoon, spread it thickly to increase the  carb count! 


Example 2.




The portion of porridge included in this example is 30g, which is typically the amount found in a single sachet of microwaveable oats. The portion is fairly small, so eating two would be quite manageable for most people. Doubling the amount of oats and milk provides a further 31g of carbs, taking the total to 118g. The amount of honey can also be increased to raise the total carb content of the meal. Bung in a tablespoon of raisins and you've got another 21g of carbs. 



Example 3.


I've double the 'standard' portion of breakfast cereal here, taking it to a 60g serving. Most people would dish themselves up 60g and think it average, so all in all I'd consider this a fairly small breakfast. Add a banana and some juice, and you've got 120g of carbs. 


Example 4.


Again, this is a fairly small breakfast, but it demonstrates how much you can make of liquid carbs if you so wish. The Nutella could be spread more thickly to increase the carb content, and is quite nice with a sliced banana on top. So I'm told... 



So let's work through a couple of case studies.



This is Barbara. She's a runner. She weighs 10 stones (63.5kg). 
It is recommended that Barbara eat 2-4g of carbohydrates per kilogram  of body weight: 
63.5 x 2 = 127g
63.5 x 4 = 254g
Therefore Barbara should aim to eat between 127-254g of carbs at breakfast. On race day, Barbara eats 2 hours before her race.
She might choose:
Two slices of toast (42g) spread with 1 tbsp honey per slice (26g) and a sliced banana (23g). With this she has a large glass (300ml) of pineapple juice (38g). This will provide 129g of carbs. And all in a fairly modest breakfast. 
      


This is Tom. He is a triathlete. He weighs 14 stones (89kg). 
89 x 2 = 178g
89 x 4 = 356g
Tom should be aiming to eat between 178 - 356g of carbs at his 
pre-race breakfast.
On race day Tom starts breakfast 4 hours before his race. He might choose to eat:
A large bowl of porridge (50g) made with 250ml milk (12g). He adds two tablespoons of raisins (42g) and a large sliced banana (32g). He drizzles over a tablespoon of honey (13g) and has a large glass (300ml) of orange juice (30g). A couple of hours later, Tom eats a bagel (42g) spread with peanut butter (3g) and drinks a 380ml Lucozade (64g) on the way to the race. This provides 288g of carbs.


So there we have it! 

What do you have for breakfast? Leave a comment and let's get some discussion going! 




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