Diet therapy

Diet can offer protection when cold conditions threaten performance

Young Girl Enjoying Hot Drink In Café At Ski ResortCold injuries and illness occur in a wide range of physical activities affecting individuals at work such as the military, farmers, road workers, winter sport athletes or those involved in outdoor pursuits such as running, cycling, mountaineering and swimming.

An understanding of the importance of sports nutrition and planning appropriate meals and snacks can offer some protection against cold injury and may also improve overall performance.

Physical responses to cold conditions

In order to find our vulnerability to cold injury it helps to first understand how the body responds to cold as it endeavours to increase heat production. This is achieved in two ways:

  1. Non-shivering activities that increase heat production without muscle contraction such as an increase in metabolic rate.
  2. Shivering, heat is produced by involuntary muscle contraction and reduced blood flow to the extremities (vasoconstriction) in an effort to prevent heat loss

Heat Loss

This occurs in 4 main ways:

  1. Radiation occurs when heat is lost directly to the environment via uncovered areas such as face, neck, head and hands and is greatest at night. This may be of concern to people who outdoors at night or go tramping and camp out at night.
  2. Convection takes place when air passes over the skin due to wind or body movement such as when running, cycling and skiing. Appropriate clothing is essential to protection.
  3. Conduction occurs when the skin surface comes in direct contact with a cold surface such as rain, snow, water immersion or wet clothing. Conduction can increase heat loss by up to 5 times with wet clothing and 25 times with water immersion. So care must be taken, particularly of children when they go swimming for extended periods of time.
  4. Evaporation is a factor when heat is lost through respiration or sweating. Respiratory losses are difficult to control, other than wearing a surgical mask or scarf over the nose and mouth. While this may not be practical for some sports it should be considered for those susceptible such as young children who are asthmatics. Sweating can occur in sports such as ice hockey or mountaineering even when attempts are made to control heat by layering clothing and altering the level of activity.

The types of cold injury experienced


This occurs at three different levels:

  1. Mild, core body temperature(cbt) drops below 35-37°C (95-98° F)
  2. Moderate cbt drops below 32-34°C (90-94°F)
  3. Severe cbt is less than 32°C( <90°F)

Prolonged exposure to cold, wet and windy conditions can result in hypothermia as experienced during endurance events, outdoor team sports such as soccer, football, mountaineering and hiking and in occupations requiring long periods outdoors or in unheated spaces. The rate of hypothermia injury is two times greater in females than males. Women lose body heat more quickly than men because they have a smaller total muscle mass and a larger surface area for convective heat loss.

Symptoms of hypothermia may include: cessation of shivering, very cold skin, impaired mental function, slurred speech and bad decision-making, impairment of gross motor functions, cardiac arrhythmia.


This can occur as a localised response to a cold, dry environment, although moisture can speed the process if sweating increases tissue cooling. Frostbite is characterised by freezing of body tissues and like hypothermia it also occurs in stages as warm blood is shunted from cold extremities to maintain a higher core temperature. The superficial tissue of hands, face, nose and ears may be the first affected when the temperature drops below -2°C( 28°F) followed by a progression to deeper tissue.

Symptoms may include swelling, mottled grey skin, transient tingling and numbness in the limbs.

Treatment for hypothermia and frostbite should include slow re-warming by applying heat first to the body trunk not extremities. Alcohol and nicotine should be avoided.


This is an inflammatory response to exposure to cold, wet conditions over a period from 1-5 hours at temperatures of 16 deg C (<50°F) resulting in swelling of the affected tissue, tenderness, itching and pain. Treatment should include drying the affected tissue, elevation and covering the affected area with loose, warm clothing or blankets.


This may affect asthmatics when the inhalation of cold air increases the respiratory heat loss triggering an attack. Those involved in high intensity activities such as skiers, cyclists and runners may be more at risk.

Risk factors to health

When placed in a cold environment some individuals will be more susceptible than others to cold injury for example:

Previous cold injury

Those who have had frostbite in the past are 2-4 times as likely to be affected again if the same area is exposed to similar environmental conditions as was first experienced

Low energy Intakes

People who consume low energy intakes e.g.1200-1500calorie intakes, suffer from hypoglycaemia (low blood sugars) or both are more likely to experience a drop in metabolic rate and heat production


Dehydration may not affect shivering however when fluids are lacking the distribution of energy to the muscles slows, thereby compromising recovery.


If people experience fatigue and this is accompanied by hypoglycaemia then peripheral circulation can be impaired along with the shivering response. Tiredness can result in poor decision-making and thereby lead indirectly to injury.


Darker skinned individuals are 2-4 times more likely than other ethnic groups to sustain cold injury. This is due to such things as anthropometric and body composition differences; a reduced cold induced vasoconstriction response and such things as thinner longer digits.

Alcohol and drugs

Alcohol consumption has the effect of reducing glucose concentration in the blood and (as with drugs) can reduce the shivering response as well as altering mental functions which in turn can lead to bad decision-making and injury.


They have a larger surface area than adults, when calculated per unit of body mass and they also have less fat to prevent heat loss. As a result, the smaller the child, the greater and more rapid, the heat loss. Their state of health is also important. Some children are smaller and thinner as a result of malnutrition, disordered eating or congenital health issues such as cystic fibrosis, heart defects and failure to thrive. These children need extra care and supervision when taking part in activities that expose them to cold conditions.

Obviously the length of time a child is exposed to cold conditions will affect the severity of change in their performance. Children who resist feelings of cold discomfort in order to continue performing in sports such as swimming may be at greater risk of hypothermia. Regular supervision of the time spent in swimming pools during training and competition is important. During swimming practice children should be allowed to come out of the water every 15-20 minutes to avoid hypothermia.

Older people

As people age there is a reduction in sympathetic nervous function reducing vasoconstriction and increasing heat loss. This can also be a problem when combined with medications or medical conditions such as cardiovascular disease, diabetes, hypothyroidism and hypertension. Athletes who enter races after 55yrs of age should have regular medical check- ups with their doctor.

Spinal injuries

People who have suffered spinal cord injuries (SCI’s) are at greater risk of hypothermia, abnormal blood pressure, numbness with cold, pain and muscle spasm. Care must therefore be taken when athletes with SCI’s compete in cold conditions.

Nutritional tips if working or competing in cold conditions

  • Start the day with a breakfast that includes hot foods such as porridge or cereal with hot milk; toast; a yoghurt, egg or cheese slice or baked beans.
  • If working or exercising in a cold environment take extra food supplies with you in case you are caught by delays or road closures. Choose foods that are portable, easy to access and handle. For more information on workplace nutrition read Lea’s article: Put sports nutrition to work
  • Good hydration is particularly important. Plan to have hot drinks, soup, trim hot chocolates and water readily available throughout the day and avoid alcohol consumption.
  • If venturing into alpine areas, hiking or mountaineering take extra dehydrated foods, portable cookers and gas and high energy snacks such as scroggin, cereal bars and dried fruits.
  • If catering for children involved in winter camps such as skiing or adventure camps at school plan menus to include hot foods and snacks with plenty of carbohydrate for energy in the form of cereals, bread, pasta and rice, fruit and vegetables. Ensure that children also carry snack foods and drink bottles with them in case they become separated from their group.
  • Children involved in water sports such as swimming need to be carefully supervised. Read Lea’s article Swim for life for more information on when and what to eat during training and competition.
  • For those athletes affected by asthma read Lea’s article on Diet may help exercise induced asthma
  • Older athletes need to check regularly with their doctor to ensure that the doses of any medications they may be taking is appropriate to their body weight and activity levels. For more information read Lea’s article on Sports nutrition for senior athletes

If you are suffering from fatigue on a regular basis then talk to you doctor and contact us to ensure that your nutritional intake matches the energy demands of your sport and daily life.



Burke.L, Deakin V. Clinical sports nutrition. McGraw Hill Australia 2nd ed 2000 Chapter 14, 378-9.
Bar-Or O, Children’s responses to exercise in cold climates: health implications. Sports science exchange Gatorade sports institute 51 vol 7 1994 no 4.
Cappert T; Stone J; Castellani J; Krause BA; Smith D; Stephens B. National athletic trainer’s association position statement: Environmental cold injuries. Journal of athletic training 2008 v 43 (6) Nov-Dec 640-658.


About the author View all

Lea Stening

Lea is one of New Zealand’s leading paediatric dietitians and also specialises in Sports Nutrition. She has specialised in Paediatric Nutrition for 31 years and in 1985 was the first paediatric dietitian to enter private practice in New Zealand. Lea helps families through her private consultations, public lectures, newspaper and magazine articles as well as television and radio interviews. Read more »

View all posts by Lea Stening »


Leave a Reply

Also in Diet Therapy View all »

  • Vitamin D for growth and immunity

    Recent research has highlighted the importance of vitamin D to respiratory health with those who are deficient being 5 times more likely to contract Covid-19. It is important for children, athletes and the elderly. Find out why? Read more »

  • Dietary Guidelines are constantly changing:...

    Although science is constantly evolving, generating new recommendations to improve our health, for many people their eating habits are based on things other than their longevity so are guidelines still relevant today? Read more »

  • Break free from Fad Diets

    New diets pop up every day. Who should we believe? NZ Broadcasting student Louise Trenouth, on assignment, puts questions to Lea in an effort to understand Fad Dieting. Read more »

  • How to make the most of a plant-based diet

    The plant-based diet is widening the range of foods on our supermarket shelves. How do they compare with standard meat and dairy products for nutrition value? Find out.. Read more »

  • Healthy At Every Size (HAES): the debate

    The Healthy at Every Size (HAES) paradigm, focusing on body acceptance and healthy lifestyle changes, is gaining a lot of media attention as a possible way of curbing our escalating obesity stats. Find out more. Read more »

  • Are you afraid of the scales?

    Everyday we measure things such as the time, money, distance, our cholesterol, petrol etc yet many people fear measuring themselves Read more »

  • Stay in ‘the loop’ for a brighter...

    Loneliness and social isolation are being increasingly seen as risk factors to good physical and mental health. Learn how to stay connected with others and improve your sense of well being in 5 easy steps. Read more »

  • Unlock your potential with food

    The power of food can change your life and Dietitians can help you unlock your potential through food. Read more »

  • 10 Tips for better food choices this Christmas

    Weight control is the key to better health but this can be hard when Christmas often leads to overconsumption. Find out where to start. Read more »

  • Dietitians and Nutritionists what’s the...

    Dietitians are the most credible source of nutrition and food knowledge when you need to apply it to health and disease in NZ. Read more »

  • Wise up to Discretionary Foods for better health

    If you are struggling to lose weight or lower your cholesterol then taking a closer look at your intake of discretionary foods can improve your results. Read more »

  • How to put ‘real’ flavour into...

    It can be so easy to snip the top off a packet of flavouring when cooking. But if we really want to reduce the salt, fat and sugar in our diet natural flavours are best. Find out how. Read more »

  • Dietary help for women with PCOS

    Polycystic ovarian syndrome (PCOS) is a common cause of infertility in 6-20% of women of reproductive age causing a range of hormonal and metabolic effects that can impact on a women's physical and mental health. Read more »

  • Garnishes galore and all those “little...

    Is garnishing getting out of hand? Find out how much energy those "add ons" really do add. Read more »

  • 7 Myths about weight loss

    Lea Stening shares 7 common myths about weight loss and concludes that "you actually need to eat quite a lot of food in order to lose weight". Read more »

  • Time your eating for better performance?

    If playing sport or exercising, understanding the GI can help you to select foods that will provide optimal energy at key stages of activity for better performance. Read more »

  • Tips to help you ‘shake off’ the...

    In a bid to reduce the intake of processed foods many food manufacturers are modifying their products to meet new food guidelines particularly regarding salt. Find out if you are still getting too much? Read more »

  • Is going “Gluten Free” a healthy...

    As the popularity of gluten- free diets grow we need to question whether in fact it is a healthy option for any of us and if not how can we make it so? Read more »

  • Does your diet tick all the boxes?

    Is dieting still fun if it ages you? Find out if your diet ticks all the boxes for your better health and performance. Read more »

  • 10 tips to prevent weight gain in marriage

    When couples move in together they set in motion changes to their long-term health. While there are many health benefits of living together managing weight may need extra care and attention Read more »

  • Don’t let energy deficiency ruin your health

    Energy deficiency is not just a problem of third world countries. It can be found in our hospitals, schools and kindergartens, rest homes and on our sports fields. It can affect over and underweight people. Read more »

  • Sports supplements should be taken with care

    While some supplements are well recognised as being useful to performance others can lead to positive drug testing and disqualification as well as endanger long-term health. Read more »

  • Changing our “weight talk” may...

    A child can build their confidence and self esteem if monitoring their growth rate is accompanied by positive health messages about weight, fitness and energy to achieve in life. Read more »

  • Don’t let stress fractures slow your...

    Stress fractures are not just a problem for athletes who overtrain. They can affect anybody as they also relate to lifestyle and nutrition choices. Find out if you at risk. Read more »

  • Nutrition for distance runners and “fun runs”

    Distance running and “fun runs” (and walks) of varying length and degree of difficulty are becoming popular, attracting family and community groups; recreational and elite participants. Paying attention to sports nutrition can improve an athletes performance and enjoyment of these events Read more »

  • Juice diets – are they as healthy as...

    For busy people, who might rather drink than chew their fruits and vegetables, the juicing trend sounds like a "gods send". What possible disadvantages could there be to health? Find out the pros and cons of this new diet craze. Read more »

  • Driving for a living? 10 tips to help your...

    Spending hours behind the wheel is a huge recipe for weight gain and increased risks to our health. Driving is something that affects us all. Read more »

  • Feeling full is the secret to weight loss

    Gaining an understanding of the many factors contributing to a sense of fullness can provide some very powerful tools for those seeking to lose or control body weight and find more energy for life! Read more »

  • Can coconut improve our health?

    Coconut oil was once associated with tanning. Something young people coated themselves with before lying out in the sun “to bake”. Today coconut products are being heralded by many as the new “wonder food" that can cure many ailments. We take a look at some of these claims. Read more »

  • Dietary help for depressed athletes

    Although athletes may benefit from an exhilarating endorphin rush on exertion that elevates their mood and suppresses feelings of pain it will not stop them from experiencing, at times, anxiety and bouts of depression just like the rest of us. Nutrition is one treatment option that can speed recovery. Read more »

  • Sugar control is essential for better health

    After years of encouraging a low fat diet with some success (a decline in heart disease and some forms of cancer) attention is now focusing on sugar as a possible reason for our weight and diabetic problems. Read more »

  • Boosting fibre intake offers health benefits

    Research shows that a diet high in fibre can reduce the risk of developing diseases such as type 2 diabetes, coronary heart disease, bowel and breast cancer, gallstones, diverticular disease and weight gain. It also seems that some fibres are better than others. Read more »

  • Healthy diet aids menopause management

    Menopause is a natural biological process women pass through and just like puberty it is not a medical illness. A woman's experience of Menopause is very individual and so there is no one "cure" for the range of symptoms that may be experienced. Read more »

  • Could the French Diet reduce obesity in New...

    The French diet is relatively high in saturated fat and yet in 2012 the French have a low incidence of obesity (11% compared to 28% in New Zealand). Why is this? Read more »

  • How to increase the ‘Good’ fats...

    If you are thinking of cutting fat out of your diet stop right now. Fat is important for nerve and cellular function but choosing the right “type” of fat is what matters most to our long term health. Read more »

  • Can a high fat diet improve sports performance?

    Fat carries more energy than other macro nutrients (9kcals/37kJ/g compared to 7kcal/29kJ/g for alcohol and 4kcal/17kJ/g for protein and carbohydrate respectively). So with so much energy to offer does eating more improve performance? Read more »

  • Healthy ideas for family takeaway meals

    Did you know that in 2012 around 21% of New Zealander’s weekly food expenditure was spent on eating out and takeaways? Read more »

  • Are you a “sneaky snacker”?

    Some people find it hard to control snacking and are continuously thinking about food. They may find themselves constantly picking, stock piling foods in drawers and cupboards at home and work. Read more »

  • Vegetarians face extra hurdles

    Despite the apparently healthier lifestyle vegetarian athletes (like anybody) can still become overweight, hungry, bloated and suffering from multiple nutrient deficiencies. Read more »

  • The gut-brain axis is important to sporting...

    Do you ever suffer from” runners diarrhoea”, bouts of anxiety , fatigue, abdominal pain or gas when facing competition? Read more »

  • Swim for your life

    Whether you are swimming for fun or competition this sport has many health benefits that can be enhanced with good nutrition. Knowing what to eat and when can also greatly improve your enjoyment of the sport as well as your level of performance. Read more »

  • Eat your way to healthier nails

    The quality, appearance and growth of our nails often reflect the state of our general health and the adequacy of some essential nutrients in our diet. Read more »

  • Skin care for active people

    The stress of competition, the sun and wind, sweat, chaffing and high sugar levels are just some of the things that can aggravate the skin conditions of athletes and very active people. Read more »

  • Care for “the carers” during family...

    When family members are sick or hospitalised it can be very challenging to find the time to exercise and maintain a healthy diet for yourself. Particularly if you are working, caring for children, or trying to complete a course of study. Read more »

  • Don’t let disordered eating ruin your...

    An eating disorder can affect anyone at any age, any sport, any background and any gender. The symptoms may build slowly well before the illness becomes evident. Often it is an athletes support team such as parents, friends, team mates and coaches that pick up on the symptoms and can prevent the disorder from ruining the athletes sporting career. Read more »

  • Could your weight be disabling you?

    The human body is hugely resilient, constantly strengthening muscles and remodeling bones and joints to take up new loads. However as we age and weight is gained and lost, metabolic changes can take place that alter this remodeling process and can set us on a path to failing mobility and independence. Read more »

  • Obesity problems may start in the womb

    Overweight and obese women are a greater risk of developing complications endangering their own health during pregnancy and are also more likely to bare children who are overweight themselves Read more »

  • Put Sports Nutrition to work

    Many workers use enough energy and essential nutrients each day to power a marathon. If not replaced then a lack of these key nutrients can lead to fatigue, accidents and injury that can affect their long-term health and mobility. Read more »

  • Athletes protect your winning smile

    Athletes protect your smile and your wallet as painful tooth erosion is not only expensive it can also rob your training time and performance. Read more »

  • 8+ Tips for managing teething troubles

    Few children escape teething without some discomfort. Rosy flushed cheeks, a runny nose, irritable behavior, disturbed sleep and bowel function are all hallmarks of tooth eruption Read more »

  • Facing the down times without weight gain

    Nothing can be more infuriating for an athlete than after months of intense training an injury sees you ‘sidelined’. Read more »

  • Sports nutrition for women

    Women who push the boundaries of their lives to take on new challenges and sporting events are usually also trying to juggle their work, home and training existence. With good sports nutrition advice It is possible to find renewed energy. Read more »

  • Who controls feeding – the mother or the...

    Studies of toddlers aged 20 months to 6 years, that examined baby-led weaning versus traditional spoon feeding methods have found that feeding method can influence food preferences and health related outcomes in later life. We look at the pros and cons. Read more »

  • Sports nutrition for cycling

    Cycling tests an athlete’s strength and endurance capabilities as well as their anaerobic energy systems during breakaways, hill climbs and sprints to the finish.While some athletes rely heavily on dietary supplements, these will not replace a healthy training diet that is high in carbohydrate, with moderate protein and low in fat. Read more »

  • The protein needs of young athletes

    At a time when they are also growing, young athletes may need as much as 50% more protein than their more sedentary peers. Read more »

  • Food to Fuel the Speights Coast to Coast

    Whether you are a novice or seasoned triathlete your nutrition plan could make or break your race. All those competing should read the excellent nutrition tips on the official Speight’s Coast to Coast website and seek professional help if they have any concerns. In addition here is a check list of things you should also consider. Read more »

  • Children’s bone growth and gut health...

    Every parent wants their children to grow. But the height that they finally reach is dependent on factors such as growth hormone, genetics and nutrient availability. While we can’t change genetics after their arrival or growth hormones easily, nutrient availability can make the difference and is something parents can influence and need to be more … Read more »

  • Nutrition for tendons and ligaments

    The recent Rugby World Cup has placed the spot light on sports injuries and so we thought it might be interesting to look more closely at the protective role of sports nutrition and in particularly the nutrients important to tendon and ligament health. Read more »

  • Brace yourself for the brassicas

    With Winter now upon us its time to eat more Brassica vegetables. What are they? Broccoli – 7th most popular vegetable in New Zealand Cauliflower – 13th most popular Cabbage (all types) – 12th most popular Brussel Sprouts Broccolini – consumption rocketing! Swedes Turnips Why are they so good? Brassicas contain: Antioxidants, from the following … Read more »

  • Infant nutrition influences blood pressure...

    Scientific evidence suggests that environmental factors acting early in life may affect blood pressure in adult life. A study in Britain in 2004 supported earlier studies on infant nutrition and blood pressure that show a small reduction in systolic blood pressure in children breast-fed compared to those who were bottle-fed. Other advantages of breastfeeding Breast … Read more »

Would you like to subscribe to our fantastic FREE monthly newsletter?

Each month we'll keep you up-to-date with the latest nutritional articles and healthy recipes from You are free to opt out at any time, but we think you'll enjoy what we've got in-store for you.

Plus as a bonus offer — subscribe today and receive FREE weight loss tips for two weeks! Learn how a number of foods, many one would consider 'healthy', may in fact be slowing your progress.


Yes please, it sounds great! (and it's FREE after all).



No thanks, I'm not interested (or I'm already a subscriber and really enjoying these fantastic newsletters!).