Where possible athletes should dry the skin with a towel before the sweat evaporates. The road racers are at an advantage here as they can carry a small sweat towel in the pockets of the cycling top. It could be suggested that water stations provide a small towel to marathon runners as well as their drinks.
Exercise in the Heat
In Beijing, the athlete’s bodies will respond to not only heat stress, but by the humidity, air velocity and thermal radiation.
Neither the muscles nor the heat loss mechanisms will have an adequate supply of blood volume.
Cardiac output will remain constant; however stroke volume may decline with heart rate increasing.
Oxygen uptake will increase.
Source: McArdle, Katch & Katch [1996]
By exercising for an hour or more in Beijing, 5 to 10 days prior to the games, cardiovascular changes will occur around day 3 but sweating mechanisms will take longer up to 10 days.
Source: Wilmore & Costill[1999]
The athletes clothing is extremely important in overcoming the elements of the weather, as clothing insulates the body from its surrounding environment. Clothing can reduce heat gain in hot environment.
Dry clothing will retard heat exchange more than wet clothing. It will be important that athletes stay cool before competition starts.
In previous games in hot extremities, Paula Radcliff [Marathon Runner] has been seen taking shelter under an umbrella with an ice pack on her upper body, which delayed the onset of her core temperature rising.
Material from which the clothing is made from is important. The ideal material will need to be lightweight and light in colour. Heat loss will be delayed until the clothing becomes wet and cooling via evaporation can proceed.
Source: Wilmore & Costill [1999]
Drinking fluids throughout prolonged exercise is essential. Fluid intake can decrease the risk of dehydration, cardiovascular stress and minimise a rise in the body’s core temperature.
Fluid intake will provide fluid availability for both evaporation and circulatory flow to the tissues.
It will be important that for the two events chosen, the marathon and the road cycle race that there is pace makers. Pace makers/setters will prevent the athletes racing too quickly in such temperatures and prevent post-race collapse.
Dehydration is the process of losing fluid from the body, in this case through sweat. As you sweat you lose water and electrolytes.
Excessive drinking can lead to HYPONATREMIA. This is a condition that results in an abnormally low concentration of sodium levels in the bloodstream. Low levels of sodium can cause cell malfunction, and in extreme cases can be fatal due to swelling of the brain. By ingesting large amounts of plain water without additional salt the sodium levels in our bloodstream will dilute. This is not a problem in the short term, but as time goes on, especially in extreme heat, the delicate balance between the body's water/sodium levels can create real problems.
During the two races mentioned “aid stations” will be allocated along the route. These stations will have water plus electrolyte and energy containing beverages. In order to calculate the fluid intake during the event, use clear water bottles to remind athletes of their intake. Sports drinks packaging should be compact so the athletes do not overload at the stations.
Each athlete will have individual fluid needs. These will need to be established to maximise performance and any potential hazards. To work out an individuals fluid needs during these prolonged events, their sweat rate needs to be calculated. According to USATF Self-Testing Program for Optimum Hydration the following calculation is used:
Sweat Rate =Body weight pre run – body weight post-run + fluid intake – urine volume/exercise time in hours.
It is important that when the athletes start training in Beijing after acclimatization that they run at race intensity for one hour and follow the below procedure:
Do a warm up where perspiration is generated
Urinate if necessary
Weigh naked on an accurate scale
Run/cycle for one hour at intensity similar to the targeted race
Drink a measured amount of a beverage of your choice during the run/cycle
Do not urinate during the run/cycle
Weigh naked again on the same scale after run/cycle
Record the data.
This will give the athlete their approximate fluid needs per hour.
Source: USATF Self Testing Program for Optimum Hydration
The heat will certainly alter the consumption of fluids. Monitor the colour of urine. If the athlete is well hydrated, their urine will be clear and light yellow. Urine that is dark or approaches the amber colour in appearance is a signal that the athletes are dehydrated and need to significantly increase their fluid intake.
“To ensure proper pre-exercise hydration, the athlete should consume approximately 500 to 600ml of water or a sports drink 2 to 3 hours before exercise and 300 to 360ml of water or a sports drink 0 to 10 minutes before exercise.”
Pre-Competition Preparation
Pre-competition preparation will require the athletes to reduce their training intensity in the build up to Beijing 2008. A reduction in training intensity will give both body and mind a break from vigorous training. This is known as Tapering.
As the athletes taper, it is important to replace training with books, magazine articles, or other materials that will provide athletes with motivation and inspiration. It is also important to familiarise the athletes with the course, either by visiting the course or via map depending on the athlete’s psychological issues.
“In the last few days, the coach should stimulate the athlete’s belief in success, aid relaxation and reading; avoid boredom by organising interesting but relaxing outings, and so on.
Source: DICK, FRANK. W Sports Training Principles,[1997],3RD Edition page 298
Finding out who will be competing in the both the marathon and the road race is also vital. These will also the athletes to know where the main competition will be from and therefore plan their strategy for their race. Being aware of the opponents on race day, the British Olympians will be able to anticipate the speed, whether to start of the race at either the front or middle of the pack, whether to run or cycle at the outside or inside lanes etc.
“The opposition must be clearly identified and known to the athlete, as not all athletes in a contest may be opponents. Information on each opponent should include previous best performance, recent history of competition, and behaviour in competition.”
Source: DICK, FRANK.W Sport Training Principles, [1997]3rd Edition, Page 298
As the intensity of training is reduced, tissue damaged can be repaired and muscular strength restored. It will also allow energy reserves to be restored.
Source: Wilmore & Costhill [1999]
Below is an example of the amount of miles to run in the weeks prior to the day of the marathon.
Tapering Schedule (Schedule III Metric)
WWW.MARATHONTRAINING.COM/MARATHON/METRIC3.HTML
When training is reduced, it is important that food intake is reduced as the athletes will be burning fewer calories. Care is needed when selecting foods in the build up to race day. Snacks and high fat foods should be avoided, nutritious and healthy foods are recommended.
In order to achieve maximum muscle glycogen stores. The athletes in question will need to increase their daily carbohydrate intake. According to Wilmore and Coshill,[1999], the recommendation for CHO intake 3 days prior to competition day is from 3012kcal to 3730kcal. This is the time when athletes may gain a couple of pounds; this will be your energy fuel during the race.
Check the weather forecast for updated information about general conditions, temperature range, and wind.
It is important that the athletes prepare their personal equipment and belongings and for the coach to ensure in particular that the cyclist’s bike is in perfect working order,
Clip long toenails and treat blisters and calluses the week or two prior to the marathon.
It is important that the athletes arrive at the event in plenty of time and rest as much as possible.
Apply a non drip high factor sunscreen all over [include lips].
Wear sunglasses that filter UVA and UVB rays and/or wear a cap with a visor
Athletes should line up or take position according to their strategy /expected pace.
Source:
During Competition
Where possible encourage the athletes to run in the shade as temperatures will be much cooler.
Before nutrients are passed into the blood, they first passed through the stomach and then onto the small intestine. Fluid and CHO consumption during exercise will impact the body’s gastrointestinal function.
The intensity of the marathon and the road cycle race will slow gastric emptying significantly. As blood flow to the intestines decrease’s during these events cramping and other symptoms will indicate that there is a disturbance. Following the below guidelines should help to limit gastric problems.
Source: Wilmore and Coshill[1999] page 484
On race day it is important the athletes fuel their bodies. Many athletes will feel nervous on the day of competition and may find eating difficult. Foods such as cereal, toast and juice are easy digested and will ensure that they athletes do not feel full. It is recommended that this meal should be eat 2 hours prior to the start of the race and should be only between 200 to 500kcal.
Source: Wilmore and Coshill[1999] page 477
“The main purpose of the pre-competition meal is to provide the athlete with adequate carbohydrate energy and to ensure optimal hydration.”
Source: McArdle, Katch & Katch [1999]page 69.
During the actual race fluid and carbohydrate intake is essential for these endurance events. As discussed earlier, temperatures will be increasing as the events continue, adrenalin sets in, and the athletes will benefit from carbohydrates and electrolytes being added in their hydration drinks. The inclusion of CHO is extremely important as each event will be intense and will last over one hour.
“An ingestion rate of 1 g min maintains optimal carbohydrate metabolism; for example, 1 litre of a 6% carbohydrate drink per hour of exercise.
Source: USATAF Proper hydration for distance running.
“High intensity aerobic exercise for one hour can decrease liver glycogen by about 55%, whereas a 2 hour strenuous workout can almost deplete the glycogen content of the liver and specifically exercised muscles.”
Source: McArdle Katch and Katch[1996] page 72
Carbohydrates, gels and sports drinks that contain more than 6% will increase the rate of carbohydrate delivery but will comprise the rate of fluid emptying from both the stomach and from the intestine. These will be seldom offered during the Beijing games. It will be the responsibility of coaches to put any gels of snacks such as energy bar at the aid stations allocated throughout the race. The practically of eating while, “on the run”, may prove difficult for marathon runner’s and may impair their stride / arm swing. Eating solids may not be the answer for the marathon, adding carbohydrates to water may be the answer. Cyclists will be at an advantage as they can easily carry any gels, bars etc in their cycle tops.
By consuming these drinks or bars and gels for cyclists, fatigue will delayed and prevent dehydration. They will also maintain blood sugar concentration. This can then be used by the muscles to spare muscle glycogen or if muscle glycogen becomes depleted, reserve glucose.
After Performance
Recovery from the physical demands after these endurance events starts immediately after crossing the finishing line. The focus of recovery is to replace muscle and liver glycogen stores, replace fluid and electrolytes lost in sweat, repair the damage caused by the exercise
The purpose of post exercise hydration is to replace the fluid lost during the race. This process can take up to 2 hours.
“Rehydration should contain water to restore hydration, carbohydrates to replenish glycogen stores and electrolytes to speed rehydration.”
Source: USATAF Proper hydration for distance running.
The heat and humidity in Beijing should cause rehydration to be rapid and the athletes may have to consume 25% more than sweat losses and urine losses that may have occurred. Rehydration in this case may take up to 4 -6 hours.
Source:
Carbohydrate intake within two hours of endurance exercise is essential to building adequate glycogen stores for continued training. The reason for this is that carbohydrate consumption stimulates insulin production, which aids the production of muscle glycogen. Combining protein with carbohydrate in the two-hours after exercise nearly doubles the insulin response, which results in more stored glycogen. Carbohydrate to protein ratio for this effect is four grams of carbohydrate for every one gram of protein.
Solid foods can work just as well as a sports drink, a drink may be easier to digest make it easier to get the right ratio and meet the 2-hour window.
“The glycemic index is a relative measure of the extent of which blood glucose increases after exercise; athletes should consume carbohydrate-containing foods [50 to 75g each hour] with a moderate to high glycemic index.”
Source; McArdle, Katch & Katch[1996]Page 77.
Eating foods in high glycemic index will replenish the body’s glycogen stores. High glycemic index foods include most breads, potatoes and high-glucose sports drinks.
In order to consume the correct fluid intake post event. The athletes will need to be weighed to work out the total amount of fluids that they lost during competition. From this, the correct fluid replacement can be achieved. Drink 16-24 ounces of fluid for every pound of body weight lost.
CONCLUSION
The games in Beijing 2008 aim to be an enchanting Far East experience.
The Great Britain team face an enduring flight and will have to adapt to the west to east time difference.
British Olympians will have to battle with the extreme weather conditions as well as battle with competitors on race day.
Planning and preparation will be vital to successful games for the British teams. In this booklet, examples of a two week preparation to the games was used, however, preparation will need to be in place, months leading up to the games.
For successful games in such hot and humid conditions, correct nutrition for the athletes is essential. Normal marathon and road race nutrition strategies can be complex but will be more so in Beijing.
Carbohydrate and fluid intake, pre, during and post race is essential to prevent dehydration, hyponatremia, and gastric problems.
Athletes competing in the Road Race will be able to carry carbohydrate gels and bars in the pockets of their shirt /vest; however, accessing drinks from water stations may prove difficult while on their bikes and will be approaching them at speed.
Marathon runners may find fluid and CHO intake during the race difficult as holding a foreign object whilst running may put them of their stride or arm swing momentum.
However off putting the consumption of fluid and carbohydrates during competition it is essential. Muscle glycogen levels can be maintained, fatigue and dehydration prevented.
Post race food intake is crucial in order to restore fluid that was lost and to replenish muscle glycogen stores. This is a time consuming process which could last up to 6 hours in Beijing.
It is important that athletes consume foods and fluids within the initial two hour window. It is advisable that these portions are small in size as large portions may make the athlete nausea.
BIBLOGRAPHY
BOOKS
Dick F. W, [1997] Sports Training Principles, A &C Black, London
McArdle, Katch, Katch, [1996] Exercise Physiology, Baltimore, Maryland, USA
Wilmore & Costill, [1999] Physiology of Sport & Exercise, Human Kinetics, Champaign, USA
WEBSITES
WWW.MARATHONTRAINING.COM/MARATHON/METRIC3.HTML
PUBLICATIONS
USATF Self Testing Program for Optimum Hydration
