Nutrition rule 2 - hydration is key

Hydration as a concept appears simple but is difficult to properly explain, and one of the most important things to get right - the body is far more sensitive to hydration than food. However, you can be dehydrated without being thirsty and vice versa - and drinking lots of plain bottled water is not necessarily the way forward.

The reason why hydration is so important is that water not only forms 60% of your body mass, but water a key role in your body processes on many levels - primarily:

• As a solvent: the body uses water (via liver and kidneys) to wash away the by-products (e.g. lactic acid, ammonia, and other toxins).
• As part of the energy cycle - Water saturated muscles burn energy more efficiently.
• As a temperature regulator - e.g. through sweating.

Dehydration on the other hand has lots of nasty effects, first of all being dizziness, nausea, headaches, tiredness, irritability, sunken features (particularly the eyes), dry mouth and throat, and skin that becomes loose or flushed. Thus it is something to pay attention to whether you are exercising or not.

For the keen sportsmen reading – it is worth noting that one of the reasons on long training exercises your heart rate rises after 45 minutes or so is actually dehydration not tiredness. Even a small drop in body fluids and electrolytes can lead to a lower circulating blood volume. That makes your heart pump harder to maintain adequate blood flow to your vital organs and your body is less able to control blood pressure, distribute nutrients and eliminate waste.

How much should you drink?

The British Dietetic Association (BDA) recommends six to eight glasses of fluid a day, which is about 1.2 litres, as does the Food Standards Agency. However that 1.2 litres includes the water in your food and is an average figure based on the British climate and takes into account an average body volume. You will need more fluids if you are exercising (somewhere between 500ml and 1.0 litre per hour of exercise), or in a hot climate, or if you have a large body volume. Rough guideline as follows:

Weight		Training level/litres fluid
(Stone)	(Kg)	Low intensity	Medium	High
8st 3	52	2.2	2.3	2.4
8 st 9	57	2.2	2.4	2.6
10st 10	68	2.2	2.4	2.8
12st 7	80	2.3	2.5	3
14st 3	91	2.3	2.6	3.2

When should you drink?

The feeling of thirst is activated 1.) when the total body water level is reduced, and 2.) by low sodium levels. Even slight dehydration reduces the blood volume triggering thirst. But thirst is sensed only after dehydration is evident, or can be a counter indicator, making thirst a poor indicator that it's time to drink more water. One good rule of thumb is to pay attention to your lower lip - if its nice and full then you are properly hydrated, if its all puckered up then you are most likely dehydrated. Other is to check the colour of your urine, gross I know, but it should be the colour of straw (supplement effects aside) rather than the colour of Fanta, as one friend charmingly put it.

What should you drink

Plain water, especially bolted down rather than sipped, will go straight through you, and will not actually contribute to your body’s hydration. If you are consuming a great deal of plain water (upwards of 2 litres a day depending on activity level) then you are possibly creating a vicious circle (see below).

Ideally what you are looking for is something with a bit of sugar and a bit of salt, or sodium to be more precise. Sports drinks are ideal – but squash, tea (green, herbal or normal), coffee (caffeine issues accepted), diluted fruit juice (to avoid the blood sugar spike) will all do fine. None of this is to say that you shouldn’t drink plain water, especially when you are eating a meal which will provide the electrolytes for you – its just a question of what makes it easiest for your body to get hold of.

One last thing - taste and hardness aside – bottled water is a wheeze in most 1st world countries where the quality of public supply is often better controlled than bottled (need I remind you of the Coca Cola/Dasani/Thames-water-in-a-bottle fiasco http://www.timesonline.co.uk/article/0,,1-1023319,00.html). That said, for those of us living in London – the tap water does taste pretty foul.

Electrolytic level/Isotonic vs Hypotonic vs Hypertonic Sports Drinks

There are two key issues with drinking plain water, firstly its harder for your body to absorb, and secondly it actually dilutes the electrolytes (salts) in your body, diluting your body's fluids. If you drink too much water, two things will follow:

• Firstly, drinking too much water will leads to increased urination, causing dehydration, then thirst, and round you go in a vicious circle.
• Secondly, when excessive amounts of water have been consumed, your kidneys will not be able to eliminate all the excess water from your body, so the electrolyte/mineral content of your blood is diluted. This will firstly result in increased urination, but will also result in extreme circumstances in a condition called hyponatremia (low sodium levels - endurance athletes see below).

Isotonic drinks contain the same number of particles per kilogram as your blood and so are quickly absorbed, and carry electrolytes with the fluid – hence why it is what you should be on the look out for. Isotonic sports drinks (e.g. Lucozade Sport, Isostar, Powerade, Gatorade and, believe it or not, Sprite, SIS PSP22 http://www.scienceinsport.com/PSP22.htm ) are designed to replace carbohydrates as well as fluid and contain 5 - 8g sugar/100mls and a little added salt. You can make your own isotonic drink as follows:

a. Dissolve 60g glucose or sugar in 1 litre water or low calorie squash and add 1/5th teaspoon salt
b. Mix 500ml fruit juice and 500ml water and add 1/5th teaspoon salt
c. Mix 200ml fruit squash and 800ml water and add 1/5th teaspoon salt Hypotonic drinks (less than 3g carbohydrate per 100ml) also enhance water absorption but provide minimal energy.

These can also be used before, during and after exercise and may be useful if you are limiting your energy intake or have to drink very large amounts of fluid daily. e.g. Dexters, Lucozade Hydro Active, SIS Go http://www.scienceinsport.com/Go.htm)

Hypertonic drinks are more concentrated (more than 10g carbohydrate per 100ml). These drinks should not normally be drunk during exercise for although they will provide energy they will delay the absorption of fluid into your body and may contribute to dehydration. They can be useful for energy replacement after exercise, rather than fluid replacement. These have a place in particular if you have a high calorie intake requirement eg SIS PSP22 and Rego http://www.scienceinsport.com/rego1.html

Comment: I actually get along much better with Hypotonic rather than Isotonic, which I tend to find too sugary and at times make me nauseous. But then I’m always cutting weight rather than trying to maintain it so it’s a choice I can make, and that’s probably a very girlie comment. When you’re competing, you’re going to be better off with Isotonic drinks, and if you find the sugar too much, then wash your mouth out with plain water after drinking an Isotonic drink. If you’re training very hard, then you will need to use Isotonic when you are training, and Hypertonic straight after (or alternatively jam sandwiches will do the same job) to replace your glycogen stores to avoid the black hole of ‘glycogen depletion’ (eg you’ve run out of fuel, so dizziness, weakness, disorientation, never fun).

Hyponatreamia

A quick comment on Hyponatremia to finish up - this is a rare condition, where the sodium levels in your blood fall critically low, either through dilution or depletion. Most people would be sick before reaching it by dilution, but it is a risk for endurance athletes such as marathon, triathlon and iron man competitors who are exercising heavily over long periods. This particularly true on a hot day when athletes are also rapidly losing salt through sweat (e.g. Marathon de Sable competitors) - note in these circumstances this is a sodium concentration issue rather than a hydration issue. There's a couple articles at the bottom under the heading "hyponatremia" with some suggestions if you think this may be a problem for you. The jury is still out on the use of salt tablets – but it does seem to be a way forward if you suck them until the salt craving goes away. Complications have been linked to mono-sodium glutamate intake (or yeast extract – watch out for that one). This is really revolting stuff and it will make you feel foul even if you’re not exercising – so packet watch on anything that is (supposed) to taste meaty or savoury, or frankly, is mass produced.

Hydration Links

http://row2k.com/columns/index.cfm?action=read&ID=20

http://www.telegraph.co.uk/fashion/main.jhtml?xml=/fashion/2005/11/20/stjoshi20.xml

http://www.ft.com/cms/s/c3a1a262-1e18-11db-9877-0000779e2340.html

http://www.bda.uk.com/Downloads/FluidBalance.pdf

Hyponatremia Links

http://en.wikipedia.org/wiki/Hyponatremia

http://www.spinalhealth.net/hyponatremia.html

http://www.rice.edu/~jenky/sports/salt.html

http://www.rrca.org/publicat/wat.htm

While we're on amino acids - Creatine's useful too

Ok - the Science In Sport quote in the previous post on Glutamine made me realise that a discussion on Creatine was probably also called for. Creatine is the other common protein supplement taken, and in my view the only other one you should consider. Everything else you need you should be able to get from your diet.

However - and this needs some heavy caveats along the lines of "research into long term use of amino acid supplements is still anecdotal, and even short term research is often poorly done" - while there is no evidence of harmful results from taking up to 40g of Glutamine a day (that's against a daily protein requirement of conservatively 40-60g) - there is some research and anecdotal evidence of negative effects of Creatine, and its a little more tricky to use.

Creatine is made up of three amino acids - Arginine, Glycine and Methionine - but its a bit more clever than just a building block for protein. In the body, creatine is changed into a molecule called "phosphocreatine". Phosphocreatine is very cunning stuff - and provides 'free energy' which doesn't require food or oxygen to produce energy in the muscles. It is the first part of the energy cycle in your muscles when you go from a standing start into exercise - the energy cycle then heads into aerobic, anaerobic and back to aerobic all things being well and good. Creatine also pulls water into your muscles, appears to help with lactic acid, and muscle synthesis - and overall making it easier for you to train harder for longer. Sound good?! Its certainly great news for anyone who has issues putting on muscle or is training very hard.

The drawback is that there is some evidence, but mainly isolated or anecdotal, that Creatine can cause nausea, diarrhoea, cramping and serious renal problems. However, no comprehensive study has proven any negative effects of taking the recommended dose of Creatine. Something else to bear in mind is that the water Creatine pulls into your muscles has to come from somewhere – and also putting amino acids through your system will increase the load on your liver and kidneys, so you need to watch your hydration. While Glutamine can actually help your kidneys, Creatine just adds to the load. The increased load on your kidneys is partly due to the final products of amino acid catabolism, which include carbonic acid and urea and ammonia (which is a base if you’ve forgotten your chemistry). It is your kidneys that manage the acid-base level of your body. Glutamine helps in regulating this because when ammonia levels are elevated, the kidneys clear ammonia from the blood by synthesizing glutamine. If the blood is too acidic (pH too low), the kidneys can break down glutamine into glutamate and ammonia to increase the pH of the blood. So, if taking Creatine seems like a good idea in the context of your current training program, buy from a reputable source (Science in Sport as ever) – follow the instructions on the label, do a maximum 5 week load and then consider stopping taking it.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10999421&dopt=Abstract

http://www.thefactsaboutfitness.com/research/creatinesafety.htm http://en.wikipedia.org/wiki/Creatine
http://www.absolute-creatine.com/http://www.scienceinsport.com/KR10.htm

The first rule is Glutamine is good

Glutamine is a non-essential amino acid - that is, our bodies can create it from other amino acids. However, that description belies its vital importance, and recent research means that it is rapidly becoming a modern day panacea.

I first came across L-Glutamine 5 years ago (L-glutamine means its the form humans can absorb). Jim McCartney, the then coach of Thames Rowing Club men's squad recommended it to the squad. Jim was of the old school of rowing coaches (lots of scowls and knowledge, few words and no concept of pain) and thus the boys in the main did as they were told, and ordered a tub and took the stuff. By the end of the year I think you could physically see the improvement in who had taken it - and Jim was later voted 2003 Coach of the Year by the sport's ruling body the ARA. Glutamine is now described by Science in Sport (good sports drink & supplement supplier) as the "hottest supplement since creatine" (see separate post on Creatine for an explanation of what it is).

The magic lies in the fact that L-glutamine is a very versatile amino acid, by far the most abundant building block of muscle (60%+) and white cells alike, and participates in many reactions in the body. Glutamine is a precursor for many other amino acids; an important fuel for the immune system, the brain and gut mucosal cells; and appears to enhance lean muscle growth and glycogen production (fuel for your muscles).

There are a whole range of applications - L-Glutamine can be helpful in the treatment of arthritis, intestinal disorders, peptic ulcers, can enhance mental functioning, and has been used to treat a range of problems including developmental disabilities, epilepsy, fatigue, impotence, schizophrenia, and senility. L-Glutamine decreases sugar cravings and the desire for alcohol, and is useful for recovering alcoholics.

From a sports point of view - during intense training, Glutamine level are greatly depleted in your body, which decreases strength, stamina and recovery. This is particularly true for people training in cold, damp conditions; which tends to depress the immune system. Thus a Glutamine supplement is vital for anyone who is training hard, particularly in cold weather.

However, Glutamine's role in the immune system and digestive system means that its not just a useful supplement for crazy sportsmen, its a useful supplement for anyone who is working hard, or even if you are just feeling a bit under the weather.

Instructions

Buy from a reputable source - Science in Sport is a good supplier, and follow the instructions on the tub. Don't forget that amino acid supplements are more effective when they don't have to compete with the amino acids in high-protein foods. Ideally take L-Glutamine at least an hour and a half before or after meals (first thing in the morning or at bedtime may be best). Oh and don’t put hot water on it unless you fancy a gelatinous goo – it is sugary in taste, and many people mix it with orange juice or squash.

Glutamine Information Sources:

http://www.scienceinsport.com/Glutamine.htm
http://en.wikipedia.org/wiki/Glutamine
http://pdrhealth.com/drug_info/
nmdrugprofiles/nutsupdrugs/lgl_0125.shtml

Cold conditions for training/illness prevention etc:
http://www.cyclecoach.com/pageID-articles-Illness.htm
http://www.pponline.co.uk/encyc/0905.htm

ZE First rule

GLUTAMINE IS GOOD

This is what bro started the blog off with - which is not a bad start so I thought I would continue:

The First rule is Glutamine is good
The Second rule is hydration is key
The Third rule is nutrition is vital to us all
The Fourth rule is carbohydrates and fats are great
and the Fifth rule and final rule is the first "old wives tale" of the blog: -

Eat what you really want, precisely when you want, and stop when you're full.

So I guess a bit of background is required before I work through the above - and I thought I'd put this here rather than in the profile which was just going to fill up space.

I have no training in nutrition at all, and my interest stemmed from the mother of all invention - necessity - so a story is required:

Several years ago when I was first sharing a flat in London with my brother, he announced that he wanted to get involved in rowing seriously for his university - which happened to be one of the best at this crazy sport. Rowing, for the wisely unaware, at the top end of the sport involves racing at heart rates of 180+ for either 7-8 minutes or 17-20 minutes depending on the time of year and fitness - Wikipedia link here:
http://en.wikipedia.org/wiki/Sport_rowing

My brother was in that all important third year of uni and I, for my part, had introduced him into the sport in the first place, and was therefore knew the difference having a supportive person around could make to a rower's performance and wellbeing. So I promised my brother that if he was really going to make a go of it, I would transport him to and from races and organise his food. Seemed simple...*ahem*

Two months later, my car and dining table had developed the uncanny ability to sprout several rowers at a time, the BLT sandwiches I stocked my car with were becoming the stuff of legend and my food bill was topping more than twice my rent. The main problem however was that although the food I was serving up did wonders for other members of my brother's crew, my classic 'ectomorph' brother was losing weight, fast, and could not put on muscle for love nor money. All of a sudden, I became very very interested in nutrition!

Since then I've spent a fair amount of time involved in competitive rowing - as a cox (steers person) and coach - and my kitchen has usually contained at least one hungry (and often cranky) rower/cyclist on the hunt for food, and at the same time those needs had to be balanced against my need as a cox to lose weight. However, as much as I've read and picked up along the way from the many brilliant coaches and oarsmen I have had the privilege to train with, I often come back to what I call 'old wives tales'. By 'old wives tales' I mean the hundred and one little bits of advice which I barely even remember being told, but if I think about it, often came from my grandmothers or their friends - both of my grandmothers were nurses at one or more points in their lives, and incredible hostesses and home-makers (for want of a better modern words). So I guess what I hope to do here is bring it all together in one place - the old and the new for better or worse!

So that's the story - now for the rules!