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.

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

Bacon or death?

Processed meat linked to early death! 

Processed meat is a killer! 

Scary sausages? Suicide salami? Death by bacon? I can imagine worse ways to go. But then, I'm very easily seduced by a bacon sandwich. I jest, of course.

It's universally accepted that what we eat has an effect on our health, and the results of a study appearing in the news today have highlighted the risks associated with eating processed meat, which includes bacon, sausages, ham and other such meaty delights.

The research has spawned headlines proclaiming the dangers of eating processed meat, with findings indicating that people who consume more than 20g of processed meat per day have an increased risk of premature death from all causes, with particular risk for cardiovascular disease and cancer.

The study, involving 448,568 people from ten European countries, forms part of the European Prospective Investigation into Cancer and Nutrition (the EPIC study). The results published today look specifically at meat consumption and a preview draft can be found here.

What the results say:

• Eating 160g or more of processed meat each day increases your risk by 44% of dying, from any cause, when compared to people who eat 20g or less. 
• The risk of cardiovascular disease and cancer are raised more than other causes of death. 
• People who eat a lot of processed meats are also more likely to have other less healthy behaviours - smoking, high alcohol consumption, and low fruit and vegetable intake.
• Even when these other behaviours are taken into account, processed meat consumption was shown to increase risk of premature death. 

So how much meat are we talking about?

20g is a small portion - one small rasher of bacon, 1/5 of a McDonald's burger, two wafer thin slices of ham or a snack-sized Pepperami.

160g is a more robust portion - 2-3 sausages, half a can of Spam, four frankfurters, etc.

If you're a dedicated carnivore, it's easy for the total consumption of processed meats to add up over the course of a day or week. Bacon sandwiches for breakfast, ham rolls for lunch, sausage and mash for dinner - you can easily go over and above the 160g amount associated with significantly increased risk.

The current recommendation from the Department of Health is that we eat no more than 70g of red or processed meat per day. It is worth differentiating between the two of these, as they are most definitely not same thing.

What exactly is processed meat?

At the risk of stating the obvious, it's meat that has been subjected to some form of processing. This includes salting, curing, smoking and other process that preserve the meat, typically involving the addition of chemical preservatives.

Processed meat tends to be higher in fat than a cut of fresh meat, and also has additives such as nitrites, nitrates and salt, which in themselves can have a detrimental effect on health.

Mincing meat is not, in itself, sufficient for it to be considered as processed. Some additional preserving process is required, for example, adding preservatives, salt, etc.

And red meat?

The term red meat is used to describe meat that is (wait for it!) red when raw. Some people quibble over pork, but it is indeed classified as a red meat.

Red meat is nutritious. It's an excellent source of protein, vitamins and minerals, particularly zinc and iron and vitamin B12. Opt for lean cuts and low-fat cooking methods and there's no reason not to include it in your diet.

This study also looked at the consumption of white meat, which includes poultry and rabbit. No effect on mortality was identified.

Red meat may be processed, but not all processed meat is red. It is worth noting that any meat can be processed: a chicken nugget, for example, is most definitely a processed (white) meat.

The processed meat in this study however, was primarily processed red meat. Small amounts of processed white meats were included, but most consisted of processed beef, pork and lamb (and to a lesser extent, goat and horse. Probably more horse than was first thought...).

So what can we learn from this study?

Red and processed meats have, for some years, been associated with an increased risk of cancer development, particularly bowel cancer. The findings associating processed meat with cardiovascular disease is new.

How significant is this risk? Well the authors have stated that 3% of deaths within the participants of the study could have been prevented - that's 869 preventable deaths. If you extend that percentage to deaths in the UK (from all causes), then there's the potential for in the region of 15,000 deaths being prevented each year.

Processed meats tend to offer no nutritional benefit over meats in their natural form. Choose lean cuts of fresh/frozen red or white meat (check for additives and veer toward white meat more than red) and eat it in moderation, and you should have nothing to worry about.

If you do want to eat processed meats, do so. But accept that there is some risk involved, as there is with many things in life. A bacon sandwich is certainly enjoyable, but is it really worth a slightly hastened death?

Hence the (ever so slightly hyperbolic) title of this post - bacon or death? The choice is yours.

So hungry I could eat a... horse?

Horse meat. 

There's been a lot of talk about it in the media of late, and for good reason - horse meat has somehow found its way into processed meat products, and people have been unknowingly been eating it for months. 

In the general furore that's sprung forth from the discovery of horse meat in the food chain, there's something that's not particularly been touched on: all moral and cultural objections aside, is horse meat any good for you?

Horse meat is eaten in numerous countries throughout the world, being considered a delicacy on various European and Asian dinner tables. 

Horse is classified as a red meat, the same category to which pork and beef belong. For the purposes of comparison to meats we're more familiar with, let's look at the nutritional composition of horse vs. both beef and pork. 

Per 100g raw product, various cuts

Horse meat contains similar levels of protein to both beef and pork, and is considerably lower in both total and saturated fats.

For people watching their fat intake for the purposes of weight maintenance/weight loss, for concern over cardiovascular disease, or for any other reason, a lean meat such as horse actually makes a healthy choice. 

Horse meat contains significantly higher levels of iron than either beef (nearly double) or pork (nearly five times as much). Iron deficiency is a common problem, particularly in women of child-bearing age, and can lead to iron deficiency anaemia. Sufferers of which are troubled by symptoms of tiredness, fatigue, breathlessness and pallor (pale complexion). Sufficient dietary intake of iron can be difficult to achieve, and people are advised to eat foods rich in iron to ensure they meet their requirements. Horse clearly tops the table with the three red meats considered here, but other options include offal, fortified breakfast cereals (check the nutrition label!) and dark green leafy vegetables. 

Athletes are often recommended to eat high quality sources of protein, minimise excess fat (being active doesn't completely guard against all diet-related diseases!), and have adequate nutrients to support their bodies in coping with the demands their training places on it. Iron deficiency can be debilitating to an athlete, so it is essential that they consume sufficient iron to prevent he onset of a deficiency. Horse meat - high in protein and iron, and low in fat, fits quite nicely into this description. Something to think about. 

Looking beyond nutrition, there has been a well publicised concern over unregulated meat in our food - the issue of drug contamination.

Bute (also known as phenylbutazone) is a painkiller. It belongs to the family of drugs known as non steroidal anti-inflammatories (NSAIDs, he same group as ibuprofen). It is commonly used in horses and dogs, for the purposes of treating pain and reducing fevers. It was once commonly used in humans, and remains a prescribable drug for human use. It is not frequently used however due to serious side effects - the drug is known to cause damage to the blood, and can lead to bone marrow failure. Whilst rare, this serious side effect was enough for the drug to be withdrawn from common use - it is now only prescribed under close supervision and where all other options have failed. 

So clearly there is cause for concern if bute has contaminated the human food chain. 

But - and it's quite a big but - based on the results of testing carried out by the Foods Standards Agency, you would have to eat a rather large quantity of horse meat in order to consume the lowest known dose to cause an adverse reaction in a human. 

These are the figures:

The lowest known dose of bute to cause an adverse reaction in a human is 200mg of phenylbutazone, administered as a single dose. 

Of the sources tested thus far, the highest level of bute found in a horse carcass is 1.9mg per kg of weight. 

Taking the lowest dose - 200mg - as a baseline, you'd have to consumed 105kg of horse meat to take in 200mg of bute. 

And that would be an awful lot of burgers. About 920 quarter pounders in fact. 

So is eating horse meat something to be worried about?

From a nutritional point of view, no. Horse meat is lean, high in protein and provides a useful source of iron and calcium.

From a pharmaceutically contaminated point of view, perhaps. But where bute is concerned, probably not. 

As for ethically and morally... well, the choice is yours.