Sports Drinks

For years water was regarded as the best fluid to be drinking, and then the word isotonics was banded about, so now the question is what should we be drinking when exercising, (I suspect the manufacturers of sport drinks have a lot of input on the benefits of drinking there specific product), Sport Drinks are not as complicated as you think, I found making them far easier than trying to remember there names (Isotonic, Hypotonic, Hypertonic), you will find below you can easily make your own and to suit your requirements.

Personally I have tried all types of sport drinks to try and see what all the fuss is about, did I feel any benefits from my old routine, to be absolutely honest I can’t say that I did, (maybe my routine was'nt far off the mark, so propably I wasn't the best candidate to try them out) but now a days I have both water and my own home made sport drink if you like, which I usually have during my breaks and use my water source (bladder type) while on the move which always contains water.

What happens to our bodys when we excersisie is the depletion of the carbohydrate stores and dehydration, the two factors our body experiences and will limit prolonged exercise.

Dehydration
Sweating is the way in which the body maintains its core temperature at 37 degrees centigrade. This results in the loss of body fluid and electrolytes (minerals such as chloride, calcium, magnesium, sodium and potassium) and if unchecked will lead to dehydration and eventually circulatory collapse and heat stroke.

How Much Should You Drink?
There are dangers in drinking either too much or too little. Drink too much and you risk hyponatremia - low blood salt level and fluid overload. Drink too little and become dehydrated. The needs will vary with many factors: the weather, your body's reaction to the exercise demands, sweat rate, etc.

Electrolytes
Electrolytes serve three general functions in the body:
• many are essential minerals
• they control osmosis of water between body compartments
• they help maintain the acid-base balance required for normal cellular activities
The sweat that evaporates from the skin contains a variety of electrolytes. The electrolyte composition of sweat is variable but comprises of the following components:
• Sodium
• Potassium
• Calcium
• Magnesium
• Chloride
• Bicarbonate
• Phosphate
• Sulphate
A litre of sweat typically contains 0.02g Calcium, 0.05g Magnesium, 1.15g Sodium, 0.23g Potassium and 1.48g Chloride. This composition will vary from person to person.

Glucose
Carbohydrate is stored as glucose in the liver and muscles and is the most efficient source of energy as it requires less oxygen to be burnt than either protein or fat.
During exercise, there is in an increased uptake of blood glucose by the muscles and to prevent blood glucose levels falling the liver produces glucose from the liver stores and lactate.
Consuming carbohydrate before, during and after exercise will help prevent blood glucose levels falling too low and help maintain the body's glycogen stores. Many athletes cannot consume food before or during exercise and therefore a formulated drink that will provide carbohydrate is required.

Hydration
Fluid absorption
Two main factors affect the speed at which fluid from a drink gets into the body:
• the speed at which it is emptied from the stomach
• the rate at which it is absorbed through the walls of the small intestine
Calculating personal fluid needs
During an endurance event, you should drink just enough to be sure you lose no more than 2% of pre-race weight. This can be achieved in the following way:
• Record your naked body weight immediately before and after a number of training sessions, along with details of distance/duration, clothing and weather conditions
• Add the amount of fluid taken during the session to the amount of weight lost - 1 kilogram (kg) is roughly equivalent to 1 litre of fluid (1lb approx. 0.5 litre)
• After a few weeks you should begin to see some patterns emerging and can calculate your sweat rate per hour
• Once you know what your sweat losses are likely to be in any given set of environmental conditions, you can plan your drinking strategy for any particular event

Drink to Thirst
Erase the old advice that you can't rely on thirst. New evidence says that thirst is the best protection for athletes when it comes to drinking the correct amount.
• Drink when you are thirsty.
• Don't drink if you aren't thirsty.
• Don't drink at every water stop at an event just because it is there or your companions are drinking.
• Rely on your thirst unless you discover it is leading you wrong, from weighing yourself before and after a workout.

Sports Drinks
There are three types of sports drink all of which contain various levels of fluid, electrolytes and carbohydrate.
Type Content
Isotonic Fluid, electrolytes and 6 to 8% carbohydrate
Hypotonic Fluids, electrolytes and a low level of carbohydrate
Hypertonic High level of carbohydrate
The osmolality of a fluid is a measure of the number of particles in a solution. In a drink, these particles will comprise of carbohydrate, electrolytes, sweeteners and preservatives. In blood plasma the particles will comprise of sodium, proteins and glucose. Blood has an osmolality of 280 to 330mOsm/kg. Drinks with an osmolality of 270 to 330mOsm/kg are said to be in balance with the body's fluid and are called Isotonic. Hypotonic fluids have fewer particles than blood and Hypertonic have more particles than blood.

Which is most suitable?
Isotonic - quickly replaces fluids lost by sweating and supplies a boost of carbohydrate. This drink is the choice for most athletes - middle and long distance running or team sports. Glucose is the body's preferred source of energy therefore it may be appropriate to consume Isotonic drinks where the carbohydrate source is glucose in a concentration of 6% to 8%
Hypotonic - quickly replaces fluids lost by sweating. Suitable for athletes who need fluid without the boost of carbohydrate e.g. jockeys and gymnasts.
Hypertonic - used to supplement daily carbohydrate intake normally after exercise to top up muscle glycogen stores. In ultra distance events, high levels of energy are required and Hypertonic drinks can be taken during exercise to meet the energy requirements. If used during exercise Hypertonic drinks need to be used in conjunction with Isotonic drinks to replace fluids.

Want to make your own?
Isotonic - 200ml of orange squash (concentrated orange), 1 litre of water and a pinch of salt (1g). Mix all the ingredients together and keep chilled
Hypotonic - 100ml of orange squash (concentrated orange), 1 litre of water and a pinch of salt (1g). Mix all the ingredients together and keep chilled.
Hypertonic - 400ml of orange squash (concentrated orange), 1 litre of water and a pinch of salt (1g). Mix all the ingredients together and keep chilled.

Seven Rules of Hydration
1. The rate of passage of water from your stomach into your small intestine depends on how much fluid is actually in your stomach. If there is lots of water there, fluid flow from stomach to intestine is like a springtime flood; if there is little water, the movement resembles a lightly dripping tap. Therefore, to increase stomach-intestinal flow (and overall absorption of water) you need to deposit a fair amount of liquid in your stomach just before you begin your exercise. In fact, 10-12 ounces of fluid is a good start. This will feel uncomfortable at first, so practice funneling this amount of beverage into your "tank" several times before an actual competition.
2. To sustain a rapid movement of fluid into your small intestine during your exertions, take three to four sips of beverage every 10 minutes if possible, or five to six swallows every 15 minutes.
3. If you are going to be exercising for less than 60 minutes, do not worry about including carbohydrate in your drink; plain water is fine. For exercise that is more prolonged you will want the carbohydrate.
4. Years of research have suggested that the correct concentration of carbohydrate in your drink is about 5 to 7%. Most commercial sports drinks fall within this range, and you can make your own 6% drink by mixing five tablespoons of table sugar with each litre of water that you use. A bit of sodium boosts absorption; one-third teaspoon of salt per litre of water is about right. Although 5 to 7% carbohydrate solutions seem to work best for most individuals, there is evidence that some endurance athletes can fare better with higher concentrations.
5. A 6% "simple sugar" drink will empty from your stomach at about the same rate as a fancy 6% "glucose polymer" beverage, so do not fall for the idea that the latter can boost water absorption or enhance your performance more than the former, and don't pay more for the glucose-polymer concoction.
6. Contrary to what you have heard, cold drinks are not absorbed into your body more quickly than warm ones. However, cold drinks are often more palatable than warm ones during exercise, so if coldness helps you to drink large quantities of fluid while you exert yourself, then keep your drinks cool.
7. Swilling drinks during exercise does NOT increase your risk of digestive-system problems. In actuality, most gut disorders that arise during exercise are caused by dehydration, not from taking in fluid. Dehydration induces nausea and discomfort by reducing blood flow to the digestive system, so keep drinking!