Drink up!

We all know how important it is to remain hydrated during sport and exercise so as to maintain our performance level. Your body needs to replace fluids, sodium, potassium, chloride and other elements lost during exertion. And while it is important to consume liquids there may be a couple of little known facts that you might be interested to add to your knowledge bank.

• Did you know that emerging data shows that simply washing the mouth with water or sports drink can effectively delay fatigue? So while consuming the necessary fluids is important, rinsing your mouth can be beneficial as well. (article 3)


• The same article suggests that people who drank fluids from freely flowing sources such as a cup or open mouth bottle consume more than those who drink from a straw? Something to think about next time you use that squeeze bottle, perhaps taking the nozzle out might be more beneficial. (article 3)


• You may not feel like your sweating as much during cold weather workouts, but you are still losing fluids while exercising in the winter. You may not need the same amount of electrolyte replacement as during the summer, but it is important to keep up fluid levels as cold-weather dehydration can increase the risk of hypothermia. (article 4)

So whether you are a recreational or high performance athlete, and it’s summer or winter it is important to check and maintain a good fluid balance to stay at your best performance level. Checkout these and other hydration-related resources at the SIRC library:

1. Hydration science-From Hype to Hyponatremia Scan’s Pulse, Summer 2009, 28(3) p.17
   
2. Gregory Seale. Water and the Energy Drink. SPED: Sport and Physical Education. May 2009, 6(1) p.8-9.
   
3. Kirkendall, Donald. Hydration: It’s Just the First Step. Soccer Journal, September-October 2009, 54(5) p. 20.
   
4. Carmichael, Chris. Drinking Problem. Outside. December 2006, 31(12) p. 80.

Beat the Heat … Cramps!

When the weather heats up and humidity sores we are all on the lookout to prevent dehydration. We’ve been taught to drink up and replace lost fluids and electrolytes. But how do we prevent the muscle cramping that can also occur during this weather? Recently it has been suggested that diluted pickle juice, mustard or vinegar can help fight off exercise-related cramping.

Cramps can be caused by a lack of acetylcholine, the neurotransmitter that stimulates your muscles to work. Mustard and pickle juice have acetic acid, which helps the body make more acetylcholine which loosens muscle tension. Apple cider vinegar is high in potassium and can help with muscle cramps caused by potassium deficiency.

While these home remedies have much anecdotal evidence, research is still being done to validate the claims.

Reference:
(2010). Combat Cramping. Lacrosse Journal, 34(1), 65.

Staying Cool When the Heat (and Humidity) is On!

Yes, these are the dog days of summer. The days Canadians long for in mid January. But now that they are here, somehow we find ourselves suffering in oppressive humidity and extreme temperatures.

But humidity can do more than make you feel tired, clammy and have a bad hair day. It can affect sports performances and just about any outdoor physical activity and how the body attempts to cool itself. When the air is saturated with water vapor, sweat from the body won’t evaporate as well as it would in lower humidity, and mostly just falls to the ground before it has a chance to cool the skin. Since the body doesn’t get any cooler, the body continues sweating. Not only can this increased demand on the thermoregulatory and cardiovascular systems of the human body potentially cause a decline in performance, this also leads to dangerous levels of dehydration because of it.

The human body uses evaporative cooling as the primary mechanism to regulate temperature. Since heat production during exercise can be as high as 15- 20 times that compared to rest, the body needs to find an efficient way to dissipate this heat and maintain a stable temperature between 36.5 and 37.5 °C.

A body that is working out in the heat and humidity can expect a typical sweat rate 1.0 – 2.5 litres per hour and in extreme temperatures and humidity, can expect rates of over 2.5 litres per hour. Developing some strategies to thermoregulate the body will decrease the risk of serious heat load.

• Stay hydrated. Increase volume intake into the body.

• If possible, take advantage of different times of the day to work out, in order to avoid high heat and humidity.

• Acclimate to the heat by regular exposure to hot environments.

• Consume adequate sodium.

• Minimize the amount of clothing worn so that it doesn’t produce an insulator effect on the skin.

The best way to know before you go is to learn about the Air Quality Heat Index (AQHI) and what it all means so that judgments and decisions on how to regulate the exercising body when the air quality is poor, can be made.

Visit these articles on air quality for more information.

Outdoor Exercise and Air Quality
Air Pollution and Exercise
SIRC Newsletter – Weather

For more information on heat and humidity, please visit SIRC.

Running a Marathon? Keep Yourself Hydrated

It’s race weekend in Ottawa! Which means people of all ages and fitness levels will be hitting the road running and walking.  With the weekend looking like it's going to be a warm one, we all have to remember to take good care of our bodies, most importantly staying hydrated.

First of all, sweat contains electrolytes and the main electrolyte lost in sweat is sodium, although how much each individual loses through sweat varies from person to person. Electrolytes are ionic solutions (salts) that exist in the form of minerals.  They play a variety of important roles in the body and are mainly comprised of:

• Calcium – which is essential for bone formation, aids in muscle contraction, blood clotting and the transmission of nerve impulses 
• Magnesium - helps the body use glucose, assists in making protein and fat, and acts as a method for energy production 
• Sodium – has the important function of helping to balance fluid levels in the body 

During prolonged workouts, especially in humid or hot conditions, sweating increases and electrolytes are lost, therefore making it harder to maintain fluid balance and can lead to dehydration.

Drinking only when thirsty will prevent over-consumption of fluids and is the safest way to hydrate during endurance exercise. Many runners believe that they need to “hyper-load” on fluids before race day. In reality, the body is not equipped to carry excess fluid and drinking too much during exercise can dilute the sodium content of blood to abnormally low levels which can cause hyponatremia.

Hyponatremia is an imbalance of water to salt in the body and can cause:

• Confusion
• Fatigue 
• Muscle Spasms 
• Vomiting 

The best course of action is not to blow by those first water stations when running a marathon, take the time to grab that paper cup and keep yourself consistently hydrated. This way you won’t dehydrate at the end of your run and lose out on performance.

So, all of you that will be running this weekend, have fun and keep drinking water!

References from the SIRC Collection

1. Anastasiou C, Kavouras S, Sidossis L, et al. Sodium Replacement and Plasma Sodium Drop During Exercise in the Heat When Fluid Intake Matches Fluid Loss. Journal Of Athletic Training [serial online].

2. Beltrami F, Hew-Butler T, Noakes T. Drinking policies and exercise-associated hyponatraemia: is anyone still promoting overdrinking?. British Journal Of Sports Medicine [serial online].

3. Clark N. Fluid Facts for Active Lifestyles. Palaestra[serial online]. Summer2007 2007;23(3):43-44.

4. Gibala M. DIET FOR SPORT PERFORMANCE & ACTIVE LIFESTYLE. Wellness Options [serial online]. 2005;(21):32-33.

5. Heaner M. To Salt or Not to Salt?: An update on sodium and how it affects health and exercise. IDEA Fitness Journal [serial online].

6. Webster S. do runners overhydrate on race day?. IDEA Fitness Journal [serial online]. November 2011;8(10):57.