Guidelines

Guidelines for sporting events during hot weather.

Why use guidelines?

Every year in South Australia a heat wave hits our State.

At that time Sports Medicine Australia (S.A.) has requests from associations, individuals and members of the media asking:

"Should our sporting event be cancelled?"

To assist organisations, coaches, teachers and other individuals when considering their "duty of care" responsibilities, SMA (SA) has produced this set of guidelines and a checklist.

The guidelines are not binding and SMA reminds all parties that they must act responsibly.

Cancellation of events or withdrawal from participation may be appropriate even in circumstances falling outside these recommendations.

When considering cancelling or postponing a specific sporting event, there are many factors that need to be considered.

Exercise in the heat creates competitive demands on the cardiovascular system which is required to increase the blood supply to the exercising muscles. At the same time it must regulate body temperature by increasing skin blood flow in order to produce the sweat that keeps the body cool.

High intensity exercise in a hot environment, with the associated fluid loss and elevation of body temperature, can lead to:

DEHYDRATION • HEAT EXHAUSTION • HEAT STROKE

Factors to be considered for cancelling sporting events.

The Wetbulb Globe Temperature

• One way of evaluating the environment is the Wetbulb Globe Temperature (WBGT). The WBGT measures thermal stress. It is a more reliable indicator than ambient temperature as it takes into account humidity. The higher the humidity, the less likely the chance to cool off through the evaporation of sweat.
• WBGT is not the same as temperature in degrees Celsius, i.e. 35 degrees Celsius 20% relative humidity is approximately a WBGT of 27.6 degrees Celsius.
• Obviously the greater the risk of thermal injury, the more you should be considering postponing / cancelling your event.
• The WBGT is available through the Bureau of Meteorology. Web-site (These details are relevant for the South Australian population).

Duration and intensity of an event

• The combination of extreme environmental conditions and sustained vigorous exercise is particularly hazardous for the athlete. The greater the intensity of the exercise the greater the risk of heat related symptoms, e.g., Distance running is more of a problem than stop-start team events.
• A reduction in playing time and extending rest periods with opportunities to rehydrate during the event, would help safe guard the health of athletes and participants.
• Provision of extra water for wetting face, clothes and hair is also important.

Acclimatisation of the participant

Preparation for exercise under hot conditions should include a period of acclimatisation to those conditions, especially if the athlete is travelling from a cool/temperate climate to compete under hot/humid conditions.

Regular exercise in hot conditions will facilitate adaptation to help prevent the athlete’s performance deteriorating, or heat illness, during later competitions. A period of 7-10 days of 60 minutes acclimatisation activity each day provides substantial preparation for safe exercise in the heat.

Fitness levels/Athletic ability of participant

• A number of physical/physiological characteristics of the athlete will influence the capacity to tolerate exercise in the heat, including body size and endurance fitness.
• In endurance events an accomplished yet non elite runner, striving to exceed their performance may suffer from heat stress. The potential for heat related illnesses will be exacerbated if they have not acclimatised to the conditions and have failed to hydrate correctly. (See case study).
• An overweight and unconditioned athlete will generally also be susceptible to heat stress.
• Sports Medicine Australia recommends athletes drink 500mls before activity, 200mls every 20 minutes during activity and more than they are thirsty for after activity (at least 500mls).
• Please refer to the free DRINK UP brochure available from your local National Pharmacy.

Age and gender of participant

• Female participants may suffer more during exercise in the heat, due to their greater percentage of body fat.
• Young children are especially at risk in the heat. Prior to puberty, the sweating mechanism, essential for effective cooling, is poorly developed. The ratio between weight and surface area in the child is also such that the body absorbs heat rapidly in hot conditions.
• In practical terms, child athletes must be protected from overexertion in hot climates, especially when required to exercise for 30 minutes or longer.
• Although children can acclimatise to exercise in the heat, they take longer to do so than adults. Coaches should be aware of this and limit training for non-acclimatised children during exposure to hot environments.
• Veteran participants may also cope less well with exercise in the heat. Reduced cardiac function is thought to be responsible for this effect.

Rules of the game (Hydration opportunities)

Will your players be able to consume enough water during the event?

• To avoid excessive dehydration during exercise in the heat, fluid (preferably water) should be consumed before, during and after exercise.

Even a small degree of dehydration will cause a decrease in performance.

• Associations may consider dividing games into shorter playing periods rather than halves to allow for extra drink breaks.

Time of day for the event:

Surface type

A shaded / protected grass exercise surface does not attract and retain as much heat as other surfaces (e.g. solid black asphalt.)

Exercise surface type and the amount of direct sunlight vary significantly with different sporting activities and therefore must be analysed for each individual sport.

Venue of an event

Predisposed medical conditions

• It is important to know if any of your athletes have a medical condition or are taking medication that may predispose them to heat illness.
• Examples include; asthma, diabetes, pregnancy, heart conditions and epilepsy. Some medications and conditions may need special allowances.

Other factors to consider

• Preventative measures can be undertaken to minimise heat injuries. Examples include the provision of shade, hats and appropriate sunscreen and drinking water.
• Availability of sports trainers or first aid personnel.
• It is important to have trained personnel available to manage heat injuries.
• Heat stroke is potentially life threatening.
  Any indication of this condition should be immediately referred for medical assessment.

Case Study: Heat illness. It can happen to you.

Each year people in the community suffer from various forms of heat illness. These usually include several athletes in pre season training and summer competitors. If you think it can’t happen to you perhaps you should read on.

The Nightmare of my first marathon. Peter Daniell.

Sunday 10th August 1997.
How I had looked forward to that date - my first marathon!

I had been a ‘runner’ for about 10 years but hadn’t tried any distance above about 15 kilometres In January 97, a mate and I decided we would give the August marathon a go. We were running virtually everyday and were confident that with some extra work we could make the 42 kilometres We read books on marathon preparation and carefully planned out training. All those early morning runs during May, June and July in the freezing cold would be worthwhile once we finished the big one. The training was going to plan - we did the half marathon in July - my mate struggled a bit but I finished it in about 1.5 hours which put me on track to do the marathon in 3.5 hours. A couple of weeks later we did a 30 kilometres race (the river run) as our last big run before the race. We did it easy and were both confident that our goal, our dream was achievable. Unfortunately my mate caught a bad virus a couple of weeks before race day and as he is a diabetic his doctor advised him against running. This was a bit of a blow as you fellow runners would know, there are times when you rely on your mates to ’keep going’. Anyhow I kept training and felt fairly confident as I lined up on King William Road. The early start meant I didn’t bother with breakfast or even a drink (this came back to haunt me). Well, the race started and the first few kilometres seemed to fly. The long run along Burbridge Road was the most enjoyable - I had teamed up with a chap from Victoria who was running his fifth marathon for the year! He was hopeful of breaking 3 hours and I thought ‘Bloody Ripper’ I was well ahead of schedule. That should have been my first warning sign. I had gone out too fast, I was still on the adrenaline rush and was running faster that my training pace. I also ignored a couple of drinks stations - completely stupid.

I had read in all the books about the importance of drinking but on the day I didn’t want to break my rhythm. Anyway I was going OK until we turned north down the beach and hit the headwind. I started to struggle a bit. By the time I got to the linear track my mate from Victoria had left me and I was tiring. The closer I got to the end, the more determined I became - (is this why my family call me pigheaded??). Then down to the last few kilometres. I kept passing a guy who periodically stopped for a walk then would pass me - that’s how fast I was running!! Anyway somewhere in the Botanic Gardens it happened - I passed out. I woke up in the back of an organiser’s car with a couple of St. Johns people peering in the window at me. I remember saying that I felt better now and could I please continue!! They said I was out of consciousness for about 10 minutes, so they took me into the St. John van and apart from being incredibly thirsty I had a massive pain in my right thigh - I just couldn’t move it, bend it or bear anyone touching it - it also appeared swollen. This is where I first met Doctor Waters - one of the doctors on call at the finish. Well they decided to get an ambulance and take me to the R.A.H. I was very dehydrated, tired, thirsty and my leg was in agony. Initially the thinking was that I broke it when I collapsed but X-rays at the hospital didn’t show anything.

By this stage I had been given some pain killers and I was quite groggy. They decided I would be admitted for the night. About mid -afternoon I had my first ‘wee’ since the race. It was as black as Coca-Cola and this is when everybody seemed to panic. Within a few minutes I was put on a drip (on the highest setting) and told to drink, drink, drink. It appears I had suffered rhabdomolysis or as it is more commonly know ‘Muscle Meltdown’. It was caused by dehydration and my body basically overheated. Dr. Waters said it was the same as people who take ecstasy pills and the body starts to melt down as it overheats. In severe cases death can occur but the worry to me apparently was kidney failure. Apparently we have these things in our wee called creatinines. I had 81,000 and the norm is about 200! At 120,000 you risk kidney failure. Anyhow I stayed on the drip day and night for 5 days plus I had to drink 3 litres of water per day. Boy did I learn how to wee in a bottle!! Gradually with physio my thigh started to recover. I had X-rays, ultrasounds, massages etc. etc. - what a nightmare - all because I didn’t drink enough and went out too fast.

On my release from hospital (complete with walking stick) Dr. Waters said no physical activity for 6 weeks. That seemed an eternity and my first few jogs were quite tentative. Although I have recovered fully it is now a mental thing as I worry when I’m running if it could happen again. I don’t know if I will ever finish a marathon now - and boy I admire those who can run them. I am running again but so far I have restricted myself to 10/12 kilometres. In closing I would like to thank a few people. Firstly Dr. Darren Waters who was/is fantastic. Also the race organisers and St. Johns people on race day who cared for me. I have also become friends with Terry Buxton (one of the magnificent seven) and he has taken a genuine interest in my welfare and has been quite an inspiration in getting me running again. Thanks Terry. Last but not least my family and staff who supported me and covered for me during those 5 days in hospital.