Children’s health will be negatively affected by poorer fitness as global temperatures rise, new research shows

Publication of her findings in the peer-reviewed journal TemperatureDr. Shawnda Morrison, an environmental physiologist, states that while physical fitness is key to tolerating higher temperatures, children are heavier and less fit than ever before.

This could put them at greater risk for heat-related health problems, such as dehydration, heat cramps, heat exhaustion or heat stroke.

She says current climate change policies are failing to adequately address children’s health needs and that encouraging children to make physical activity part of their daily lives must be a priority if they are to cope life in a warmer world.

Dr. Morrison, from the Slovenian University of Ljubljana, Faculty of Sports, is an expert in adaptive and integrative human physiology in extreme environments. She has more than 20 years of experience researching sports performance and exercise physiology, especially in warm environments.

Her ratings are based on a comprehensive review of more than 150 medical and scientific studies into how children stay physically active, exercise, cope with heat, and how this could change as global temperatures rise.

The research she highlights includes a study of 457 boys aged 5 to 12 years old in primary schools in Thailand, which found that overweight young people were more than twice as likely to have problems regulating their body temperature as young people who were overweight. normal weight when they exercised outdoors.

Using emergency room data from children’s hospitals in the US, another study found that attendance was higher during warmer days. Younger children in particular often required emergency care.

The research also found:

• The aerobic fitness of children is 30% lower than that of their parents at the same age.
• There has been a rapid decline in children’s physical activity worldwide, especially over the past thirty years
• Most children do not meet the World Health Organization guideline for an average of at least 60 minutes of physical activity per day.
• Physical inactivity increased, especially in Europe, during the Covid-19 pandemic, when schools and other social infrastructures were closed.

Rising temperatures can further limit physical activity when parents of children find the outdoor temperature “too hot for play,” making it more uncomfortable for untrained or unfit children to meet the minimum physical activity levels to stay healthy, says Dr. Morrison, who is also the founder of Active Healthy Kids Slovenia.

Higher temperatures and changes in weather patterns are also expected to lead to the outbreak of new diseases entering the human population. If more movement restrictions are introduced to contain emerging diseases, this will have potentially devastating consequences for children’s physical fitness, mental and physical health.

Dr. Morrison also points out that, in terms of thermoregulation – how the body maintains its internal or core temperature – young children are not simply smaller adults. When exposed to heat, children sweat less than adults; they lose heat by increasing blood flow to their skin – a process that requires the heart to work relatively harder.

Despite these differences, most research into how the body adapts to higher temperatures has been conducted in adults. The little mechanistic research that has been done in children was largely conducted 15 to 30 years ago, when children’s fitness was much higher than it is today.

Dr. Morrison concludes: ‘Fitter adults are better able to tolerate higher temperatures, thanks to a combination of physiological, behavioral and psychological factors.

“But now that the world is getting warmer, children have never been so fit. It is imperative that children are encouraged to exercise daily to build and maintain their fitness so that they enjoy moving their bodies. They don’t feel like doing ‘work’ or ‘a chore’.”

Activities can include a combination of structured games, such as football, basketball and baseball, and active play with friends and family, preferably outdoors.

Physical education classes taught by PE teachers are the best and most cost-effective way to increase fitness levels and equip children to continue exercising throughout their lives. Families also have a role to play, especially if schools offer little physical education.

Dr. Morrison says: “Do what you love, whether it’s a bike ride or rollerblading with the family, a walk in the woods or walking the dog.

“Make sure the activity gets everyone’s heart rate, enthusiasm and positive energy up and, most importantly, don’t try to avoid the heat completely, but choose times of the day that are less hot (mornings/evenings) to stay active , because we have to keep ourselves moving in this new warming world.”

As part of Dr. Morrison’s ongoing work, she wants to determine how physically active children and adults are during heat waves, and how hot, uncomfortable or thirsty they feel when performing these activities.