HOW TO AVOID COLD WEATHER INJURIES
This blog looks at the kind of issues that can arise when training in cold weather, whether a fitness instructor is holding outdoor classes, such as boot camp training, or advising clients who like to exercise in the early morning or the evening.
Outdoor exercise, from jogging to playing football, may take place in freezing temperatures in the winter and wet weather most of the year round. Many of the factors associated with training in warm weather can be even more relevant in cold weather, including:
- Age and gender
- Fitness levels
- Clothing worn
- Type and intensity of exercise
The physiological responses to the cold include vasoconstriction of the blood vessels, which close down to keep heat in, whereas exercising in warm weather results in vaso-dilation, when vessels open up to allow the dispersal of heat. It is possible for those who regularly exercise in cold conditions to find their bodies will acclimatise, but only to a limited degree, and personal trainers should be aware that anthropometric differences are more relevant than physical fitness when assessing different people’s ability to withstand the cold.
THE ACSM’S POSITION STAND
The American College of Sports Medicine produced a Position Stand on ‘Prevention of Cold Injuries during Exercise’ (Nov 2006, Vol 38, issue 11), which stated that:
“exercise can be performed safely in most cold-weather environments without incurring cold-weather injuries”.
At the same time it recognised the importance of fitness professionals and sports trainers being able to recognise the signs of cold-weather injuries and to identify those particularly at risk. This is also relevant to anyone organising outdoor races, such as marathons and fun runs, especially when non-professionals are taking part.
COMMON COLD WEATHER INJURIES AND CONDITIONS
When exposed to the cold, the body responds by reducing peripheral blood flow. This can make it harder for those training or carrying out sporting activities to hold a piece of equipment or catch a ball. The body will also shiver in an attempt to induce thermogenesis – increased heat production.
The effects of severe cold can include:
Hypothermia – when heat loss is higher than heat production in the body and the core temperature lowers to below 35°C (95°F). Early symptoms of shivering and apathy can progress to more severe symptoms such as confusion, tiredness and slurred speech.
Frostbite – damage to skin and tissue, usually the extremities such as hands, feet, ears, nose and lips, caused by extreme cold and tissue temperature under 0.55°C (31°F).
Cold urticarial – also known as cold allergy or cold-induced hives, when the skin forms hives or welts in an allergic reaction to the cold.
Personal trainers should keep a close eye on clients with asthma, as thiscan be exacerbated by the cold. Also, if a fitness instructor is working with a client who is dieting or fasting, this can affect their blood sugar levels and lead to acute hypoglycaemia, with a reduction in lipids making it harder for the client to shiver and warm themselves up.
TIPS FOR COLD WEATHER EXERCISE
Running exercise classes, boot camps and other activities are a good alternative to the gym environment, but personal trainers holding these kinds of classes should ensure that clients are coping with the cold or wet weather.
Initially, the fitness instructor should monitor the temperature, including paying attention to the wind chill factor and whether it’s raining. They should also make an assessment of those taking part in the exercise to identify any high-risk candidates.
Personal trainers should also ensure that clients are wearing suitable clothing. For example, tight, compression clothing in breathable fabrics will help keep the heat in, while wicking away moisture from sweat. The best option is to wear a base layer of compression clothing, with a warmer insulating level such as a fleece on top, followed by a light windproof and rainproof outer layer.
Clients will have different clothing requirements to keep them warm depending on their individual needs and how they approach the exercise, for example, some may be working harder than others and will need fewer layers of clothing. Over long distances, for example hiking or hill walking, clients may need to carry a change of dry clothing with them.
NONFREEZING COLD INJURIES
Nonfreezing cold injuries (NFCIs) include:
Trenchfoot – caused by prolonged exposure to temperatures between 0°C and 15°C (32°F-60°F) and exacerbated by wet socks. The foot will become swollen and numb and move from a red to a pale colour. It tends to develop from wearing wet socks and shoes over a period of days so is only really found in those hiking or embarking on expeditions. It can be avoided by changing wet socks for dry ones and ensuring boots are dried out after getting wet.
Chilblains – less serious than trenchfoot, this mostly affects the fingers and face and comprises swollen, itchy and painful lesions, which ease once the person returns to the warmth.
As well as assessing and monitoring the weather conditions and the readiness of the participants, fitness instructors working in cold weather should have a contingency plan in place in case of weather conditions deteriorating. They may also want to devise shorter exercise programmes and ensure that participants have access to indoor facilities should they need to go and warm up.