Summer Safety: Preventing Heat Illness

Heat illness is a broad term that encompasses several conditions, ranging from mild heat cramps to heat stroke. Heat illness is typically caused by a combination of hot environment, strenuous exercise, inadequate adaptation to the heat, age, hydration levels and/or a poor choice of clothing. It’s always a risk in summer sports, particularly football and running.

Many factors can contribute to a person experiencing heat illness:

Acclimation/Environment: The increase in outside temperatures in spring can be problematic for many athletes if they don’t get the opportunity ease into the change. Acclimatization is the process of becoming adjusted to your environment gradually over time. If athletes in training are pushed too hard too fast, there is an increase risk that they will experience some form of heat illness.

Fitness Level/Adaptation: In order to cool the body the heart needs to pump harder to get the blood to flow out to the skin. If you are overweight or have a low fitness level, extreme heat can be an added strain on the cardiovascular system even without adding exercise into the mix. So if you decide to start training in the spring and summer, allow your body ample time to adapt to the exercise as well as the changing conditions.

Age: As we age, we do not adjust as well to sudden changes in temperature. Elderly people are also more likely to have a chronic medical condition that changes the normal body responses to heat or medication that alters their body’s ability to adapt to extreme heat. Older adults can protect themselves from heat illness by avoiding strenuous exercise during the hottest parts of the day, seeking air-conditioned environments, or taking a cool shower or bath.

Dehydration: On average, we lose about three litres of water each day through perspiration, urine and respiration. When you add a workout in on a hot day, you can quickly see how replenishing your body’s water becomes even more necessary. Even mild levels of dehydration (3-5% of body weight) can hurt athletic performance. How do you know if you are drinking enough? A good sign of hydration is the output of large volumes of clear, dilute urine.

Clothing: Loose, lightweight material allows for better air circulation and facilitates evaporation of sweat. Clothing should be lightweight, light-coloured, and loose-fitting such as cotton or a wicking fabric; avoid dark, non-breathing synthetic clothing.

Symptoms of heat stress may include:

• normal or elevated body temperature 
• body rash 
• profuse sweating 
• fast, shallow breathing and/or a fast, weak pulse 
• heat cramps, nausea, vomiting, or diarrhea 
• exhaustion, headache, dizziness, weakness, or fainting 

Heat injury is preventable and prevention begins with understanding the causes of heat illness. Knowing the signs of heat injury will reduce the number of potential injuries and allow you to train and exercise safely during the summer.

References from the SIRC Collection:

1. Crandall C, González-Alonso J. Cardiovascular function in the heat-stressed human. Acta Physiologica. August 2010;199(4):407-423. 
2. Johnson E, Kolkhorst F, Richburg A, Schmitz A, Martinez J, Armstrong L. Specific Exercise Heat Stress Protocol for a Triathlete's Return from Exertional Heat Stroke. Current Sports Medicine Reports (Lippincott Williams & Wilkins). March 2013;12(2):106-109. 
3. LAROSE J, WRIGHT H, SIGAL R, BOULAY P, HARDCASTLE S, KENNY G. Do Older Females Store More Heat than Younger Females during Exercise in the Heat?. Medicine & Science In Sports & Exercise. December 2013;45(12):2265-2276. 
4. Roberts W. Heat stress and athletic participation. International Sportmed Journal. June 2008;9(2):67-73. Schlader Z, Stannard S, Mündel T. Exercise and heat stress: performance, fatigue and exhaustion—a hot topic. British Journal Of Sports Medicine. January 2011;45(1):3-5. 
5. Tsukasa I, Naoyuki H. Effects of Heat Stress on Ocular Blood Flow during Exhaustive Exercise. Journal Of Sports Science & Medicine. March 2014;13(1):172-179. 
6. YAMAZAKI F. Importance of Heat Acclimation in the Prevention of Heat Illness during Sports Activity and Work. Advances In Exercise & Sports Physiology. November 2012;18(3):53-59.

How does the weather affect your asthma?

Spring is in the air and the change in the weather is a nice relief from the long winter. However, for children who have asthma, especially if they are physically active, it can be a challenging time of year. Fluctuations in the weather at this time of year can trigger an asthma attack. Being aware of this fact can help minimize the impact.

According to the Asthma Society of Canada, nearly 3 million Canadians live with asthma. There are many different triggers that can bring on your asthma which differ from person to person. Some common triggers are:

• Allergens and Irritants 
• Respiratory infections 
• Weather conditions 
• Physical activity 
• Emotions 

Knowing what triggers your asthma is a good way to avoid and minimize the possibility of an attack.

As the weather conditions change an asthma attack can be triggered by:

1. Cold air – If cold air is one of your triggers try breathing through your nose. Your nose is designed to warm and humidify air. Wear a scarf covering your mouth and nose and avoid exercising in extremely cold weather. 
2. Wind and rain – Wet weather encourages the growth of mold. The wind blows mold and pollen through the air. Limit your outdoor exposure. 
3. Heat and humidity – Hot days increase the ozone from smog, exhaust fumes and pollutants, that can trigger asthma attack. Humidity, which creates a lot of moisture in the air, can also trigger an attack. On such days stay inside where there is an air-conditioner and good quality air. 

Though you cannot control the weather, understanding what weather triggers may cause your asthma can help you lessen the possibility of an attack. Monitoring the weather forecast and signing up for weather updates can help you manage and stay on top of the circumstances which may pre-empt an attack.

References Available from the SIRC Collection:

1. Butcher J. Exercise-induced Asthma in the Competitive Cold Weather Athlete. Current Sports Medicine Reports (American College Of Sports Medicine). December 2006;5(6):284-288.

2. Carey B, Chen I. Tomorrow's weather: Thunder and asthma. Health (Time Inc. Health). July 1996;10(4):23.

3. Carlsen K, Hem E, Stensrud T. Asthma in adolescent athletes. British Journal Of Sports Medicine. December 15, 2011;45(16):1266-1271.

4. Laitano O, Martins J, Mattiello R, Perrone C, Fischer G, Meyer F. Sweat Electrolyte Loss in Asthmatic Children During Exercise in the Heat. Pediatric Exercise Science. May 2008;20(2):121-128.

5. McGrew C. NCAA Football and Conditioning Drills. Current Sports Medicine Reports (American College Of Sports Medicine). July 2010;9(4):185-186.

6. Ueda K, Nitta H, Odajima H. The effects of weather, air pollutants, and Asian dust on hospitalization for asthma in Fukuoka. Environmental Health & Preventive Medicine. November 2010;15(6):350-357.

Environmental factors in exercise and sports performance

Preparing for competition requires physical and mental training, proper nutrition, and recovery. It is also essential to understand your competition and how each athlete fits within the team dynamics. These factors, for the most part, are all factors that can be controlled. Then there are factors such as the temperature, allergens, pollution and altitude that cannot be controlled and can have serious effects on human performance.

Environmental factors such as temperature during competition can hinder performance if not taken seriously. The average body temperature is 37°C (98.6°F). In cool and warm weather, wearing the appropriate gear to be able to perform at a high level is necessary. For example, when playing soccer during the month of November in Canada, there is a good chance it will be cold. To reduce the risk of injury and poor performance, athletes have to do a proper warm up, wear the appropriate clothing and stay properly hydrated. In very hot and or humid temperatures, hydrating becomes extremely important. For athletes, cooling off using wet sponges, and wearing breathable clothing can minimize overheating.

Athletes with allergies or those who have respiratory issues can see a decrease in performance due to environmental factors such as high pollen count or poor air quality. Understanding the air quality and pollen count of the competition and training venues is important as this can enable athletes to limit their exposure by training when the counts are low, or taking the proper precautions during mandatory field times.

High altitude can create disadvantages for athletes who are not acclimatized to the higher elevation. For endurance athletes, high altitude can create limitations to training due to their inability to train as intensely as they would at sea level. At such high elevations, the air is thinner, meaning that there is less oxygen. There is also the likelihood of loss of appetite, which could lead to weight loss and compromised recovery times.

Environmental factors, if not anticipated, can give rise to:

• Dehydration, heat stroke, hyperthermia and frostbite due to changes in temperature 
• Difficulty breathing in places with high pollen counts and poor air quality.
• Altitude sickness, weight loss, loss of appetite at high altitude.

Regardless of the environmental factors, and unless told otherwise, most athletes will train and compete under most conditions. One factor to help mitigate poor performance is acclimatization. Getting your athletes used to the environmental conditions they will compete in can be advantageous since they can adapt to the conditions and as such, these conditions will not be a surprise to the athletes. Both the player and coaching staff have to understand and prepare for the adverse environmental factors that might hinder an athlete’s ability to perform at peak shape. Having a proper plan to anticipate environmental conditions is an advantage to the athletes and team performance. Though many environmental factors cannot be controlled, doing your homework beforehand can help limit the potentially negative effect on performance. Having proper equipment and gear, acclimatizing to the conditions by training in comparable conditions, and understanding how the environment will effect the athletes provide a crucial advantage to athletes hoping to compete at their best.

References from the SIRC Collection:

1. Borresen J. Environmental considerations for athletic performance at the 2008 Beijing Olympic Games. International Sportmed Journal. June 2008;9(2):44-55. 
2.  Igor R, Vladimir I, Milos M, Goran B. New tendencies in the application of altitude training in sport preparation. Journal Of Physical Education & Sport / Citius Altius Fortius. June 2011;11(2):200-204. 
3. Lane A, Terry P, Stevens M, Barney S, Dinsdale S. Mood responses to athletic performance in extreme environments. Journal Of Sports Sciences. October 2004;22(10):886-897. 
4. Nimmo M. The application of research to athletic performance in the cold. International Sportmed Journal. December 2005;6(4):224-235. 
5. Moss D. Training & Competing in Smoggy Conditions. Tricks Of The Trade For Middle Distance, Distance & Cross-Country Running. June 2004;:71-75. 
6. Rundell K. Effect of air pollution on athlete health and performance. British Journal Of Sports Medicine. May 2012;46(6):407-412. 7. 
Singh R. Hydration strategies for exercise performance in hot environment. British Journal Of Sports Medicine. September 2, 2010;44:i40. 
8. Wilber R. Current trends in altitude training. / Les tendances actuelles de l'entrainement en altitude. Sports Medicine. 2001;31(4):249-265.

Helping Kids Beat the Heat!

Winter has ended and the long awaited days of summer have begun. Children are moving their competitions and practices from indoor facilities to the outdoors leaving behind recycled air for fresh air. However, with summer starting and more outdoor activities on the schedule, it is a good idea to make sure your children are well hydrated as they participate in physical activity in hotter weather.

It is important while participating in any physical activity in the heat to be well hydrated for the activity. Drinking water before and during each break in the activity will minimize your chances of dehydration. Children should be consuming liquids before they are thirsty as opposed to after because when thirst hits, they are already dehydrated.

Here are a few pointers you might want to consider before letting your children exercise in the heat.  

• Check the weather and consider doing the activity early in the morning or late in the evening when it is cooler. 
• Carry a water bottle or consider bringing fruits such as watermelon and berries.
• Dress them in lightweight material such as dry fit, light colors and include a hat. 
• Know your children’s limits in the heat and acclimatize them gradually. 
• Be aware of dehydration symptoms. 

Exposure to extreme heat can lead to dehydration causing heat exhaustion, heat cramps and in the worst cases, heat stroke and even death. Dehydration occurs when more fluids, i.e. sweat or urine, leave the body than are replaced. Sweating is important, as it is the mechanism which allows your body to cool off. Urine colour can help to determine how well you are hydrated. Clear or light coloured urine is an indication you are well hydrated and a dark yellow or amber colour is usually a sign of dehydration.

Children are more likely to forget to hydrate during hot summer days. It is critical that parents, coaches or whoever is supervising the physical activities ensure that they keep hydrated. Being outside in the sun is a great way for children to stay fit, learn new skills, make new friends and have fun.

References from the SIRC Collection:

1. Bergeron M. Youth Sports: Keeping Kids Safe in the Heat. ACSM Fit Society Page. April 2013;15(1):3-4. 
2. Cleary M, Hetzler R, Wasson D, Wages J, Stickley C, Kimura I. Hydration Behaviors Before and After an Educational and Prescribed Hydration Intervention in Adolescent Athletes. Journal Of Athletic Training. May 2012;47(3):273-281. 
3. Johnston Molloy C, Gandy J, Cunningham C, Glennon Slattery C. An exploration of factors that influence the regular consumption of water by Irish primary school children. Journal Of Human Nutrition & Dietetics. October 2008;21(5):512-515. 
4. Nugent L. Sports Drinks. Modern Athlete & Coach. October 2012;50(4):17-18. 
5. Rowland T. Fluid Replacement Requirements for Child Athletes. Sports Medicine. April 2011;41(4):279-288. 
6. von Duvillard S, Arciero P, Tietjen-Smith T, Alford K. Sports Drinks, Exercise Training, and Competition. Current Sports Medicine Reports (American College Of Sports Medicine). July 2008;7(4):202-208. 
7. Williams C, Blackwell J. Hydration Status, Fluid Intake, and Electrolyte Losses in Youth Soccer Players. International Journal Of Sports Physiology & Performance. December 2012;7(4):367-374.
8. Yeargin S, Casa D, Sparrow S, et al. HEAT ACCLIMATIZATION AND HYDRATION STATUS OF AMERICAN FOOTBALL PLAYERS DURING INITIAL SUMMER WORKOUTS. Journal Of Strength & Conditioning Research (Allen Press Publishing Services Inc.). August 2006;20(3):463-470.

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.

Can’t Beat Mother Nature – So Be Prepared

Now more than ever, and especially in light of the tornadic devastation that tore apart the town of Joplin, Missouri on the weekend, the sporting and outdoor recreation community needs a reminder of the power of Mother Nature’s fierce intensity.

As we travel through spring and get into the swing of all our summer outdoor sports programs and activities, all event organizers, officials, participants, parents and spectators should be cognizant of the weather safety rules associated with being outside during Canada’s summer sporting months.

Did you know there is a 30-30 Rule that outlines important safety tips regarding lightening? Take appropriate shelter when the count is 30 seconds or less between lightning and thunder and remain sheltered for 30 minutes after the last thunder. In partnership, Environment Canada and SIRC have quick reference business cards on lightening safety tips that can be printed out and distributed to all constituent groups associated with an event.

Severe weather is most often predicted and communicated by a multitude of resources now. Technology makes it so much easier to be prepared for inclement and dangerous weather systems. But sometimes it all happens so fast. Weather is still something we haven’t figured out how to change or control, so this is why there is value in knowing what is expected so everyone can react quickly and stay safe. Listen to the Weather Network before the game. Turn on the radio. Add a weather application to the Smartphone. Sign up for text alerts. Even get a weather radio. It might just save a life.

Tennis, soccer, softball, golf, cycling, camping or canoeing – know the weather rules before you go.

Visit the SIRC website for more information on weather safety.

Exercising in a heat wave…

According to the news we are experiencing a heat wave in Ottawa. This means that we have three or more consecutive days of temperatures over 32ºC. However, the humidex is pushing it up to 44ºC and that is H-O-T!

How does this effect physical activity? It’s the summer, and for most their days and evening are made up of outdoor activities. Rising temperatures call for smart planning when preparing for exercise outdoors.

Stay hydrated! Heat and humidity will increase the amount of fluid loss from the body.
Morning exercise. This is the coolest time of day.
Acclimatize; start out slowly to let your body adjust to the heat.
Rest when you need to.
Think safety first. Heat stroke and other forms of heat illnesses are preventable.

There are many resources in the SIRC Collection about exercising in the heat. A few examples are:

• Dreher, Beth. Heat Advisory. Runner’s World. 45 (8)Aug 2010: 27
• Karp J. Exercising in the Heat. IDEA Fitness Journal. June 2010;7(6):26-29.
• McDermott B, Casa D, Yeargin S, Ganio M, Armstrong L, Maresh C. Recovery and Return Activity Following Exertional Heat Stroke: Considerations for the Sports Medicine Staff. Journal of Sport Rehabilitation. August 2007;16(3):163-181.

Also, check out some of our online weather resources for additional information.