How To Assess Our Children's Physical Fitness?

As the 2024 Olympic and Paralympic Games approach, it seems appropriate to ask questions about the physical condition of our children.

Physical condition is defined as:

"the level at which one can perform daily tasks with vigor and alertness, without undue fatigue, with sufficient energy to enjoy leisure activities and respond to unexpected emergencies."

Health-related fitness includes several components, such as:

• cardiorespiratory fitness (cardiorespiratory endurance)
• musculoskeletal fitness (muscular strength and endurance, flexibility)
• motor skills (speed, agility, coordination, balance) and
• certain anthropometric characteristics (such as body composition including fat mass and lean mass).

It is now widely proven that physical fitness is a powerful marker of current and future good health in children and adolescents. However, it is known that children's physical fitness tends to deteriorate in recent decades. What exactly is the situation in France?

Physical condition: an important marker of child health

Physical fitness is, in fact, associated with multiple health benefits. Thus, a high level of physical fitness reduces the risk of developing the most common chronic diseases and increases longevity.

Among the various components of physical fitness, cardiorespiratory endurance is the ability of the heart and lung system to supply oxygen to the various muscles used during prolonged physical activity. It allows intense physical activities to be carried out for a long time without excessive fatigue.

Cardiorespiratory endurance has shown the most robust associations with health in childhood and adulthood. Research also shows that good levels of cardiorespiratory endurance have positive effects on mental health.

In addition, several recent large-sample studies have supported previous findings linking cardiorespiratory endurance during childhood and adolescence to all-cause mortality and to mortality related to cardiovascular diseases and cancers in adulthood. The authors have also shown that low physical fitness during adolescence was strongly associated with the presence of a disability in adulthood and the receipt of a disability pension.

Cardiorespiratory endurance is therefore the component that is most associated with health, and its measurement in children is necessary to better assess the health status of our children. In 2020, scientific experts from the American Heart Association stressed the importance of evaluating it regularly.

Cardiorespiratory endurance in children: how to assess it?

Cardiorespiratory endurance can be assessed by laboratory or field tests:

• Laboratory testing is not suitable for epidemiological investigations due to its cost, the time required and the limited number of laboratories with trained staff and adequate equipment.
• Field tests appear to be a good alternative for assessing cardiorespiratory fitness in children, particularly in a school setting.
• Various field tests have been used to evaluate it. They include long-duration or long-distance running tests as well as so-called "shuttle" running tests. The most common is the 20-meter shuttle running test, developed by Luc Léger and his collaborators.

This test consists of having children run back and forth between two lines spaced 20 meters apart until exhaustion. This is a test starting at 8.5 km/h with an increment of 0.5 km/h every minute. The pace of the race is imposed by a soundtrack.

The test is over when the child can no longer keep up with this pace. The speed reached during the last completed stage is then recorded. This corresponds to their maximum aerobic speed (MAS) expressed in km/h and therefore reflects their maximum cardiorespiratory capacity.

Performance down in France

There has been a significant decline in cardiorespiratory endurance among children in France since 1999, although the decline appears to be slowing down.

Because cardiorespiratory endurance is an important indicator of children's health today and in their later adult lives, these current trends likely reflect population health status and can thus provide insight into the effectiveness of public health recommendations and fitness and physical activity interventions and programs.

In a recent study, we collected data on cardiorespiratory endurance measurements carried out on 15,420 children between 1999 and 2023. This work shows a significant drop (18.4%) in the cardiorespiratory capacities of our children in France over this period.

One positive note, however: this decrease seems to have been slowing down since 2010. Health prevention efforts within the framework of public policies must therefore be continued to further limit this deterioration in children's physical condition.

What are the ways to maintain children’s physical condition?

Several avenues can be explored to improve children's health capital:

Fight against excess weight

Although the prevalence of childhood overweight and obesity in France appears to be stagnating, it remains high and therefore has a direct impact on the fitness levels of French children.

Fight against a sedentary lifestyle

While the time spent in sedentary activities (lying down or sitting outside of sleep periods or in front of a screen) has increased considerably in recent years among young people, this sedentary lifestyle has a very harmful impact on their cardiorespiratory capacities .

Promote sports practice in clubs or associations

Previous studies show that enrolling a child in a sports club can be instrumental in potentially beneficial changes in physical condition.

Promoting so-called “active” travel

Children who walked or cycled – so-called "active" modes of transport – from home to school were in better physical condition than their counterparts who used "passive" modes of transport such as cars or buses.

Adapting school schedules

A European study evaluated the impact of two school rhythms on children's physical fitness (long versus short time spent inside the school). The long time corresponded to school days ending after 3 p.m. and which included several longer breaks compared to the short time where children finished before 3 p.m. with very little break time.

It has been shown that children with a long school schedule (finishing after 3 p.m. and including several longer breaks) have better cardiorespiratory endurance than children with a short school schedule (finishing before 3 p.m. and with few recreational breaks).

Arrange the school environment

Developing modifications to the school environment such as marking playgrounds, demarcating physical activity areas, and providing sports equipment within playgrounds could also help children improve their physical fitness.

Enjoying the legacy of Paris 2024

Launched in September 2020, as part of the legacy measures of the Paris 2024 Games, the “30 minutes of daily physical activity” programme in primary schools is also a potential lever for improving physical fitness.

However, to measure the beneficial effects, it will be necessary to set up standardized and validated assessments of children's physical condition and to repeat them over time, for example as part of the regular monitoring of the health of the French.

This article was first published by Vanhelst Jeremy, Lecturer in STAPS, Sorbonne Paris Nord University, and Jean-Michel Oppert, PUPH and head of the Nutrition department at Pitié-Salpêtrière hospital, Sorbonne University in The Conversation.