Avoiding heat illnesses in sports ( Part 1)

Eantihypertensives, tricyclic antidepressants, thyroxine and benzodiazepines.

In general terms, players should be advised to minimize the use of all medication ( where possible). The use of alcohol can also predispose to thermal illness.

5. Acclimatization: This is an issue for teams travelling to a hot environndurance sporting activities such ment. Where possible, a team should as Football, rugby or netball, arrive well in advance of competitive amongst others are frequently matches. played in hot and humid conditions. This allows acclimatization to occur

In some situations, especially when and can be a very effective way of both there is also high humidity, players may preventing heat illness and thereby develop heat illness. enhancing performance. After travel

During exercise, the body core temling to a hot climate, athletes adapt, perature rises and may exceed 40° C. leading to an increased plasma volume

Heat is produced from endogenous and venous tone and alterations in the sources, such as muscle activity and sweating mechanism. These sweating metabolism, and exogenous sources, changes include earlier onset of sweatwhere heat is transferred to the body ing, an increased amount of sweating, when environmental temperature and an increased dilution of the sweat. exceeds body temperature. When the This means that the sweat has a lower environmental temperature equals or sodium concentration. All of these exceeds the body temperature, evapochanges allow an athlete to perform ration is the predominant mechanism better in a hot environment. of heat loss, providing approximately The minimum time required for

90 percent of the heat loss capacity. heat acclimatization for aerobic per

In hot temperatures, an increasing dated during ambient temperatures formance is probably two weeks. Howfraction of cardiac output is directed more than 38° C ( in practicality at inever, within six to ten days, significant to the skin ( in an attempt to cool the tervals of each playing half). It is, howadaptations can occur and adaptations player), thereby limiting performance. ever, essential to recognize that even occur more rapidly in highly trained

In football, the intermittent character well- hydrated players can be affected athletes. of the effort ( short bouts of sprinting Ambient temperature in relation to by heat illness. With respect to hydraIt is usually recommended to live and and running in between periods of risk ( applicable to our setting): tion, dehydration of at least ~ 2 percent train in hot conditions for at least 60 walking) limits energy expenditure and 25- 31.9 degrees Celsius: moderate body mass is needed to impair aerobic minutes per day throughout this time allows players to adjust their speed ac32- 38 degrees Celsius: High performance in warm- hot conditions. but adaptations have been shown with cording to the thermal load. However, > 38 degrees Celsius: Extreme Practical strategies that can be used to shorter durations of heat exposure. The professional and elite players are more 2. Wearing appropriate clothing: monitor hydration include the color of adaptive responses are individualized athletic. They may push themselves Lightweight, breathable clothing is a player’s urine and measuring pre- and and appear to vary significantly across harder than recreational players and needed when training and playing in post- exercise body weights. These can footballers.

30 BG SPORT may be more at risk of developing heat As with the medical conditions hot conditions. This type of clothing be good educational strategies for playThe benefits of acclimatization are Botswana Guardian

August illness, however the latter are also at related to the environmental stressors, allows evaporative cooling to occur ers and can reinforce the need to pay www. lost botswanaguardian. more slowly than co. they bw are gained

Glory to Glody risk playing in such conditions. Playprevention is possible and is a key ( evaporation of sweat). Heavier items more attention to hydration. – usually over two to four weeks. Heat ing in an enclosed stadium may also consideration. Mandatory cooling of clothing can limit heat loss through acclimatization may also have some impose an increased risk as the playing breaks were established in various this source. 4. Avoid medication putting athletes benefit as a training stimulus field is shielded from wind, the stadium sporting codes and are key to prevent NB: Do not use black plastics as unat risk: The use of some medications leading to improved performance in walls may reflect radiation and there the development of heat- related illness dergarments for the purpose of weight can increase the chance of developing a temperate environment. is additional thermal radiation from in players and/ or referees on the field of loss or endurance gain during these hot heat illness. The use of caffeine suppleIn all aspects prevention as outlined heated walls. play. Broadly speaking, the prevention conditions. mentation prior to a game, common above remains key in our setting where

In professional settings, objective of heat illness can be achieved through among many elite players, can increase we don’t have capacity for immediate measurements are usually done by the five key areas. 3. Appropriate hydration: Ensuring the risk of problems. Other medicamedical support in the event of heat aid of a wet bulb globe thermometer that players are hydrated is an importions which may predispose to heat related illness or emergencies in sports

( WBGT) as the best measurement 1. Avoid adverse times of day for tant strategy. Water breaks in the 30th illness include phenylephrine ( in cold which we will focus on in the next of heat stress. In its absence ambient training or matches: Where possible, and 75th minute of the game are man- and flu tablets), antihistamines, some edition. temperature may be used to guide assessment of heat illness risk during sporting activity. The risk is proportional with temperature rise:

PREVENTION OF HEAT ILLNESS IN FOOTBALL

matches should be scheduled for cooler times of the day. Playing in hot conditions both increases the risk of heat illness and impairs performance. Event organizers should attempt to organize matches at a time where less heat stress and exposure is expected. They should reschedule matches where the heat stress is extreme.