EXERCISING IN HOT WEATHER CONDITIONS

Outdoor activity can be more challenging when the temperature soars. Make sure you stay safe during hot-weather exercise by drinking enough fluids, wearing appropriate clothing and timing your workout to avoid extreme heat.

Normally, sweating regulates your body temperature. A number of factors can limit the sweat response, including intense exercise in high temperatures or high humidity, age, obesity, fever, dehydration, illness, medications and alcohol. When a person develops a heat illness, it usually occurs after prolonged exertion with excessive sweating. The result is dehydration and then electrolyte imbalances.

Older people are especially susceptible to heat-related illness such as dehydration, heat exhaustion and heat stroke while exercising in hot weather. Following some basic guidelines and heeding all warning signs and symptoms, no matter how mild, can prevent the most serious heat illness in older people partaking in outdoor exercise. However, if these warning signs are ignored, they may progress into a life-threatening heat emergency.

Warning Signs:

1. Muscle cramps
2. Headache
3. Dizziness
4. Light headedness
5. Extreme thirst
6. Breathing Difficulties

Exercising in hot weather puts extra stress on your heart and lungs. Both the exercise itself and the air temperature increase your body temperature. To dissipate heat, more blood circulates through your skin. This leaves less blood for your muscles, which increases your heart rate.

When you exercise, the working muscles in your body generate heat, which is transported around your body via the blood. As your body temperature increases, the blood vessels near your skin open up and your sweat glands work harder. The evaporation of sweat from the surface of your body and the release of heat from your blood to the air, cools your body. In this way, your body tries to maintain its ideal temperature of 37°C.

Under normal conditions, your skin, blood vessels and perspiration level adjust to the heat. But these natural cooling systems may fail if you’re exposed to high temperatures and humidity for too long. The result may be a heat-related illness, such as heat cramps, heat exhaustion or heatstroke. If the humidity is high, your body faces additional stress because sweat doesn’t readily evaporate from your skin — which only pushes your body temperature higher.

Exercising in hot/humid conditions may cause your body to sweat heavily and water is therefore lost from your blood. If you do not replace this loss by drinking fluids, your blood volume will be reduced. That means your heart has to pump even harder to get the smaller volume of blood to your working muscles, skin and the other body parts..

Your heart is sending a constant supply of oxygenated blood to your exercising muscles, so there will be an increased demand on it. In this situation, there is a greater risk of damage to your heart so do not stress it to the point of feeling symptoms. When you lose too much fluid, your body temperature rises and your nervous system doesn't work properly either. Be aware that extreme fluid loss can lead to brain and heart damage.

Precautions must therefore be taken to help your body cope with exercise in hot weather:

• DRINK PLENTY OF WATER 30 minutes before you exercise.

Don’t wait to feel thirsty while you are exercising. Once you are thirsty your body is suffering from the effects of dehydration.

• REPLACE LOST ELECTROLYTES

As you sweat vital salts and minerals are leeched from your body. It’s important to maintain sodium and electrolyte levels if you are sweating profusely and exercising for over 60 minutes. The easiest way to replace these are with naturally salty foods or ‘healthy’ sports drinks but be aware of the high sugar content in most sports drinks.

• DON’T EXERCIE IN THE MIDDLE OF THE DAY.

Try exercising in the early morning or late afternoon but certainly not in the full sun in the middle of the day.

WEAR APPROPRIATE CLOTHING

Choose lightweight, light-coloured, loose-fitting, natural fibre clothing. Make a point of choosing cotton, woollen or silk socks so that your feet can sweat naturally.

• USE SUNSCREEN

Sunburn decreases your ability to cool yourself and causes fluid loss. Use a natural sunscreen with SPF 15 or higher. Wear a hat to provide shade but choose one, which allows ventilation.

• ACCLIMATIZE TO THE HEAT

You will have a greater tolerance for exercise in the heat if you become accustomed to it slowly over one to two weeks. If travelling to a hotter climate, allow several days to acclimatize before doing intense, outdoor exercise.

• USE YOUR COMMON SENSE

Avoid hot foods, alcohol and heavy foods, which increase your core temperature. If you feel any headaches, fatigue or irritability or notice your exercise performance decreasing, stop the exercise immediately and cool down.

Understand that it is easier to prevent heat illness than to treat it once signs and symptoms develop.