Conditioning Research

This one amused me, especially in the light of Matt Stone's recent post! In the past I've had a few posts up on this blog which had tried to state that the meme of 8 glasses of water a day had no basis in science - for example the Water Myth! Then this news release pops up on Eureka: Cranky today? Even mild dehydration can alter our moods Scary stuff. But of  course if you read further you get this interesting bit of information: The dehydration studies were supported by Danone Research of France Danone?  Oh that's right, Danone sell Evian and Volvic water ..... is it any surprise that they want you to drink more of it?! Get real folks.   The modern obsession with water is a marketing trick.

I've had things on here before questioning the modern myth that we need to drink 8 classes of water a day. The Guardian had something on this today "What people don't need to do is take in two extra litres a day," says Goldfarb. "You're going to take in two litres a day based on your diet and thirst sensation. What [bottled water companies] are really asking people to do is take in four or five litres, because they're already taking in two or three as coffee, tea, soft drinks, fruit, alcoholic beverages – that's all water. This notion is a marketing ploy."

So if you are dehydrated - 3% body mass loss - there will be: impaired resistance exercise performance, decreased repetitions, increased perceived exertion, and hindered HR recovery. Makes water into a performance enhancer! Impact of dehydration on a full body resistance exercise protocol This study examined effects of dehydration on a full body resistance exercise workout. Ten males completed two trials: heat exposed (with 100% fluid replacement) (HE) and dehydration (~3% body mass loss with no fluid replacement) (DEHY) achieved via hot water bath (~39°C). Following HE and DEHY, participants performed three sets to failure (using predetermined 12 repetition maximum) of bench press, lat pull down, overhead press, barbell curl, triceps press, and leg press with a 2-min recovery between each set and 2 min between exercises. A paired t test showed total repetitions (all sets combined) were significantly lower for DEHY: (144.1 ± 26.6 repetitions) versus HE: (169.4 ± 29.1 repetitions). AN...

I've posted before that the whole idea of having to have 8 glasses of water a day is a myth. In the primal blueprint there is also no need for so much water . It all sounds nice and theoretical....until you see a story like this: A mother died after drinking four litres of water in under two hours, an inquest has heard

I've had a few posts in the past casting doubt on the oft-repeated mantra that we need 8 glasses of water a day (for example here and here ) However that is not to say that water intake / hydration is not important. If you don't have enough water in your system you are likely to have more stress hormones - (cortisol and norepinephrine) less testosterone altered carbohydrate and lipid metabolism at least according to this study . I'd still tend to think that thirst is the key. Drink what you need to keep thirst at bay. I like what Joe Friel says : Over the last few weeks I’ve been rethinking what I understand and believe about hydration during exercise. In a single sentence, here is what I’ve come to believe endurance athletes should do during exercise in regards to hydration: Drink when thirsty; don’t drink when not thirsty. For shorter endurance events – those lasting less than, let’s say, four hours – that’s a not a huge change. And the shorter the event the more lik...

This looks interesting..... pdf available too Milk: the new sports drink? A Review . There has been growing interest in the potential use of bovine milk as an exercise beverage, especially during recovery from resistance training and endurance sports. Based on the limited research, milk appears to be an effective post-resistance exercise beverage that results in favourable acute alterations in protein metabolism. Milk consumption acutely increases muscle protein synthesis, leading to an improved net muscle protein balance. Furthermore, when post-exercise milk consumption is combined with resistance training (12 weeks minimum), greater increases in muscle hypertrophy and lean mass have been observed. Although research with milk is limited, there is some evidence to suggest that milk may be an effective post-exercise beverage for endurance activities. Low-fat milk has been shown to be as effective, if not more effective, than commercially available sports drinks as a rehydration beverage...

I've had posts in the past which have thought about water. There is an oft repeated prescription that we need 8 glasses a day, a prescription that has been shown to be a myth . Drinking too much can actually be dangerous . The basic idea I think is to drink according to thirst - not an earth-shattering idea but an important one. Be that as it may, it is still important to drink. Way back I posted a study which said that not having enough water in your system limits strength, power and high-intensity endurance. Here is another study which says the same sort of thing and more: If you don't have enough water in your system you are likely to have more stress hormones - (cortisol and norepinephrine) less testosterone altered carbohydrate and lipid metabolism The implication seems to be that if you want to promote muscle growth and minimise muscle breakdown, then you need to be adequately hydrated. I'd need to read the whole paper to get more, but this is certainly inte...

I've posted before about the idea that we may not need as much water as is sometimes prescribed. This 8 glasses a day thing is a myth and in fact thirst is the best guide to how much you need. Mark Sisson has put up a good article on this idea - Drink Less Water? It got me thinking that when I am hillwalking, water is the heaviest thing in my pack. I know someone that sets off with 4 litres - and that is a huge extra weight. Personally, setting off with 2 litres of water, it is rare that I will have drunk it all even at the end of an 8 or 10 hour walk unless it is really hot. So it is just extra weight to heft around. Of course I could drink from streams but I've not got that hardcore yet. I also remember once seeing some guys camping near a stream and taking water from it, then 100 yards away, seeing a rotting dead sheep lodged in the rocks at the bottom of a waterfall just upstream. I'm sure they were ok but the memory of the smell of that sheep still lingers.

We have touched on this before . Here is another study which indicates that rather than giving blanket advice to people to drink x amount of fluid - e.g. 8 glasses a day - thirst is the best guideline to intake. Of course people trying to sell sports drinks would have you believe something different! Drinking policies and exercise-associated hyponatraemia: Is anyone still promoting overdrinking? OBJECTIVES : The purpose of this review is to describe the evolution of hydration research and advice on drinking during exercise from published scientific papers, books and non-scientific material (advertisements and magazine contents) and detail how erroneous advice is likely propagated throughout the global sports medicine community. DESIGN : Hydration advice from sports-linked entities, the scientific community, exercise physiology textbooks and non-scientific sources was analyzed historically and compared with the most recent scientific evidence. CONCLUSIONS : Drinking policies during e...

Everywhere you look, people are carrying plastic bottles of water....you see it at work, on the bus, in the theatre, in church(why?!)....it is as if we are living in a chronically dehydrated society in which people are dying of thirst.... What is going on? Partly I believe that it is a fashion thing. There is a tipping point process going on in which eventually it is the standard thing to be drinking lots of water. The science as far as I can see is fairly clear : the 8 glasses a day mantra lacks scientific proof and is basically an urban myth . What is the harm of drinking lots of water? "The fact is that, potentially, there is harm even in water," explains Valtin. Even modest increases in fluid intake can result in "water intoxication" if one's kidneys are unable to excrete enough water (urine). Such instances are not unheard of, and they have led to mental confusion and even death in athletes, in teenagers after ingesting the recreational drug Ecstasy, a...

We are often told to make sure we are properly hydrated in order to perform well in endurance exercise, but what about strength and power training? This research indicates that having enough fluid in your system is also vital to performing at your best in terms of strength. This is another one of those studies that sort of confirm something that we all know deep down. In thinking about this, however, remember that the "Drink 8 glasses a day" thing is a myth..... Hydration and muscular performance : does fluid balance affect strength, power and high-intensity endurance? Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but A critical review of the available literature suggests hypohydration (not having enough water in your system) limits strengt...