Hydration Blog

Hydration at the Malaysian Grand Prix.....

Tuesday, March 27, 2023

The Malaysian Formula 1 GP is considered to be the toughest race on the F1 calendar with the heat and humidity taking its toll on the drivers and race crew. Not surprisingly, according to a recent press release Lucozade prepared a special race formulation drink specific to the Mclaren drivers Button and Hamilton http://paddocktalk.com/news/html/story-186284.  Helen Cowie, Technical Director, GlaxoSmithKline Research & Development admits that '....drivers can lose up to three kilos in sweat – roughly five per cent of their body weight......' But  as the drivers are restricted to 1 litre of drink in the cockpit it is imperative that every drop contributes to performance.  

Although the article is based upon science and supports the basis of what we do at Precision Hydration, it fails to mention that Button and Hamilton (and for that matter every single F1 driver on the start grid) have sweat sodium losses that are genetically determined and vary upto 8-fold. Getting this sodium content in the drink is important as sodium is what determines retention of water in the body.  Bespoke hydration in motorsport is not exclusive to Lucozade either as at Precision Hydration we've been doing it since 2009.  In fact our very first client was an endurance rally driver from Kenya who would typically almost pass out on Day 2 or 3 in the heat despite drinking litres of water.  He was tested using the Precision Hydration sweat sodium analysis system and found to be a very high sodium sweater.  With drinking water alone he would dilute his blood sodium leading to water intoxication (mild hyponatraemia).  On bespoke sodium replacement drinks he is now extremely competitive. Since his success our regular clients include Tuthills Porsche Team, David Brabham (ex-F1 and Le Mans winner) and Bradley Smith in Moto2 as well as numerous drivers in GT racing and rallying where the cockpit temperatures can be incredibly high. 

Hyponatraemia in marathon running; featured in the Telegraph - comments from Dr Jutley...

Monday, March 26, 2023

Taken from the Telegraph 26th March 2012:


The article reports the dangers of over-drinking which it claims 'can be deadlier than dehydration'.  The article is actually talking about a potentially fatal but little recognised condition called Exercise Associated Hyponatraemia (EAH) or 'water intoxication' where athletes develop low sodium levels in their blood.  This comes about from replacing sweat sodium losses with low sodium drinks or worse still water alone. With EAH water moves into the brain causing swelling. The athlete typically suffers from poor coordination, confusion, vomiting and often collapse. 

A study published only this year by two London universities showed that 12% of London Marathon runners were planning on a drinking strategy that put them at risk of EAH and that only 35% actually understood its cause and effects.

So how do you go about preventing it? Firstly you have to understand who is at risk of developing it and what conditions predispose to it. The table below shows these factors (ref: Rosner and Kirven, CJASN, 2007)
Exercise duration >4 h or slow running/exercise pace
Female gender (may be explained by lower body weight)
Low body weight
Excessive drinking (>1.5 L/h) during the event
Pre-exercise overhydration
Abundant availability of drinking fluids at the event
Nonsteroidal anti-inflammatory drugs (not all studies)
Extreme hot or cold environment
The other crucial factor (not really mentioned in the Telegraph article) is to appreciate how much sodium you are losing in every litre of sweat. 

You can either have this done at a lab using absorbent patches applied to your body which are then sent off to the lab for analysis once you saturate them with sweat. Alternatively you can have a Precision Hydration sweat analysis done at our centres http://www.myh2pro.com/sweat-testing in UK or Canada and soon in New Zealand. For those unable to take the test we can also estimate what your losses are via a quick questionnaire. 

Call us on +44(0)1273 900277 and we can take you through this over the 'phone. 

The results allow us to recommend which H2Pro Hydrate product should be right for you. From our own work and current published work the average athlete's sweat sodium loss per litre is 920 mg.  Considering that most sports drinks provide far less than this (Hi-5 Zero provides 500mg/litre; Gatorade 450mg/litre; Powerade 225mg/litre for example) you can understand why even drinking these can result in net sodium loss with the risk of developing EAH.  We avoid this problem by supplying drinks with 250, 500, 1000 and 1500 mg of sodium per litre to cater for all athletes so EAH is less of a possibility....


Coconut water as a sports drink....Dr Jutley's thoughts.....*UPDATED*

Sunday, March 11, 2023

Since writing this post the following email landed in my inbox. It seems the Consumer Law Group (CLG) have filed a suit against a coconut water company for making claims that it is a good substitute for a sports drink:

Consumer Law Group files lawsuit against Vita Coco

Rebecca Prescott 12 Mar 2012

Consumer Law Group (CLG) has launched a national class action lawsuit against All Market on behalf of individuals who have purchased the product Vita Coco coconut water.

CLG has said that the class action involves the deceptive, misleading, false, and unfair advertising of Vita Coco as an electrolyte induced beverage similar to a sports drink.

In fact, in an independent study it was found that Vita Coco Coconut Water did not contain the amount of nutrients specified on the product’s label. In tests, it was sown that there was 40% less sodium than advertised (only 18mg out of its listed 30mg), 35% less magnesium (only 20.80 out of its listed 32mg), and 16% less potassium (only 432.60 out of its listed 515mg)

In addition, Vita Coco contains much less sodium than a sports drink, which is the key mineral lost during sweating and is, therefore, not effective for sports recovery, the group said.

Therefore, consumers of Vita Coco would not have agreed to buy a product which does not contain the level of nutrients that was represented to them and certainly would not have consented to pay a premium price for it, according to CLG.

Source: CLG

I felt compelled to post this in response to an article I saw entitled:


See http://frugivoremag.com/2012/03/ditch-the-sports-drink-coconut-water-is-natures-way-to-rehydrate/ 

We're seeing coconut water touted as 'natures electrolyte' more and more often I'm really not sure about this! The article does make some valid observations about the high energy/sugar content of some sports drinks not being needed when you are not training hard but the comments on electrolyte balance are not completely accurate.

While coconut water may be natural I'm not convinced that its the best way to hydrate before, during and after exercise.  For very gentle sessions perhaps it might be ok once in a while but I certainly wouldn't be telling anyone to ditch the sports drinks as recommended by the author.  The article does advise against drinking too much to avoid over-hydration and hyponatraemia (low blood sodium) which it admits can be life-threatening (very true).  However, coconut water typically contains only 160mg sodium per litre which is much less than the average sweat sodium losses in humans of around 920 mg per litre so the issue of hyponatraemia is not really avoided by using it.  Then there's the high potassium content (Potassium is not a bad thing in reasonable quantities in protecting against diabetes and high blood pressure) but one litre of coconut water contains over 60% of your daily potassium requirements.  In long hot events if used as a primary hydrator, even with 3 litres the total potassium load will be 1.8 times the daily requirement plus whatever is taken via sports gels and normal food intake. I use Potassium to stop the heart during cardiac surgery so would be extremely hesitant in advising people to drink large volumes of a potassium rich drink when exercising hard or sweating a lot.

The bottom line is that sodium, not potassium, is the key electrolyte you need to replace when sweating and this is summed up nicely with the quote below:

"The only electrolyte added to drinks consumed during exercise that is known to confer physiological benefit is sodium.”

Report of the Scientific Committee on Food on composition and specification of food intended to meet the expenditure of intense muscular effort, especially for sportsmen. 2001. 

Dr Raj Jutley. CMO Precision Hydration ltd.