viernes, 12 de noviembre de 2010

Hydration and Training PART I

Hi everyone!

I would first of all, thank you all for your support. It was nice to see that this initiative has been accepted and have already begun to see the first questions to arise.

Following what is the tone of this blog, I will begin by telling you a little bit of my daily practice, feelings, and perhaps some of the ideas behind them.

This Sunday I am running in the Nice-Cannes Marathon, 42.195 k by the waterfront, really a wonderful landscape and this year will involve at least 11,000 runners from around the world.

I have thought of running with some friends, but I will consider it as training. I started training again after the Nice's IRONMAN a month ago and my expectations are consistent with that fact.

In view of this today jogging was smooth. The idea, after a good warm up was to get my legs used to the pace I hope to have in the race to avoid splitting it too fast (this is crucial when covering long distances), then a good cool down , stretching and the inevitable post-workout shake. I felt very good, but I think I'm missing a few hours of sleep.

In a future post I will talk about the structure of training and post-workout's nutrition important to accompany the practice of any type of physical activity.

Responding to concerns raised by one of you today's topic will be HYDRATION AND TRAINING.

PART I: Short-term training.

Hydration is the mainstay of our diet, some authors even propose a reformulation of the food pyramid, saying that this should include water as a base (see [1]). This is not a strange process, because the composition of our body is in a 45.5 to 60.6% water (see [4]), and changes in this ratio can have consequences ranging from changes in thermal regulatory capacity  and homeostatic imbalance, if the loss is around 2%, to cardiac arrest and death if the loss is between 7-10% (see [2] [3]). It is for this reason that any person who decides to venture into the practice of physical activity should strive to include an adequate intake of fluids during the day, this process not limited only to periods of training.

The following video illustrates what can happen if we would take the dehydration process far beyond what is recommended.

Note: No need to review the link to understand the rest of the article, in fact the images can be rather shocking.

Anyway, with the aim of reassuring, we will do some calculations.
Consider a 26-year-old men of 70 kg. weight. Since the composition of water in the body is between 60 and 65% (for this age), then an adult with these characteristics has on average 42 to 45.5 kg. water. A loss of 2%, is then translated into a loss of 1.4 kg. and a loss of between 7-10% will be 4.9 to 7 kg. Which appears to be to much, reason why we should be quiet about it.

An important factor to consider is that the sensation of thirst is an advanced symptom of dehydration (thirst appears to have lost 1% by weight), is for this reason that during the practice of physical activity should not be expected to appear this symptom to begin the intake of fluids.

While the loss of body water increases significantly with physical activity, the good news is that our body produces water by metabolizing food, it is for this reason that if physical activity is of low intensity and short duration (less than one hour), unless carried out in a hot environment, extra water intake is not needed. Anyway, it's a good idea to drink small amounts of liquid every twenty or thirty minutes, again as part of a light-moderate activity.

Overall consumption of beverages with added sugar is not necessary for activities lasting less than an hour, given that the body can sustain them through the glycogen reservoirs.

Considering the above, general guidelines for proper hydration in the presence of regular physical activity of light-moderate intensity are as follows,

1 .- Drinking fluids before, during and after training. It is very important to create the habit of consuming fluids during training, and that this could be uncomfortable in the absence of practice.

2 .- Drink at least 2 to 2.5 liters of water a day. You should drink 500 ml. of water two hours before exercise and 500 ml. additional 30 min. before, and 120 - 200 ml. every 15-20 minutes during activity.

3 .- Avoid drinking diuretics such as alcohol, tea, soft drinks.

4 .- Avoid adding salt to food. Adding salt to foods can increase the speed in which the body loses salt through sweat during physical activity.

The considerations change according to the conditions and type of activity. In a next post I will talk about hydration in extreme conditions, both in intensity and environmental.

Being clear about the importance of hydration for any person engaged in physical activity, the possible consequences of poor hydration and basic recommendations to include in our daily life, now I will try to give a precise answer to the question of Carolina.

To me, hydration is an essential issue, often made the mistake of not taking care of my hydration and suffered the consequences of such carelessness. Certainly, the fluid intake is much more comfortable during cycling than jogging, although it is clear that it is important for both activities. To solve the problem of hydration during training running, I implemented three types of solutions

1 .- Use of accessory created for liquid transport.
It is the most expensive option but in my opinion the best. There are a lot of brands that have solved the problem by creating accessories specially designed for it, these range from belts to bags. They have the advantage that you can prepare some kind of special drink for longer or more intense sessions.

2 .- Training in a circuit with water intakes.
It is not uncommon to find instances where we can drink water in our way of training. The defect is that we stop to it, but ultimately this is far better to suffer the effects of dehydration, a good idea is to pick tracks where you know in advance that you will have the opportunity to take water at regular intervals .

3 .- "Hiding a bottle."
You can leave your house with a bottle filled with water and leave it somewhere in the circuit that you know you'll pass with regularly. Remember that you should be drinking fluids every 15-20 minutes of activity, so you won't have to visit too often "the hiding place."

I hope these small indications have been helpful. I want to remark that the process of sweating also entails a significant loss of nutrients, dI will speak a little bit of this fact in the next publication because if training is of short duration and mild to moderate intensity, this aspect does not play a crucial role.

With 294 days to the great challenge, I would like to thank you very much for your attention! Have a nice day and enjoy physical activity!


Some references,

[1] GONZALEZ-GROSS, Marcela, GUTIERREZ, Angel, MESA, José Luis et al. La nutrición en la práctica deportiva: Adaptación de la pirámide nutricional a las características de la dieta del deportista. ALAN, dic. 2001, vol.51, no.4, p.321-331. ISSN 0004-0622.

[2] Naghii MR. The significance of water in sport and weight control. Nutr Health 2000; 14(2): 127-132.

[3] Armstrong LE, Epstein Y. Fluid-Electrolyte Balance During Labor and Exercise: Concepts and Misconceptions. Int J Sport Nutr 1999; 9(1): 1-12.

[4] La hidratación en la actividad física. Revista Digital - Buenos Aires - Año 10 - N° 73 - Junio de 2004.

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