Details of the study highlight the need to keep promoting physical activity among teens, and, in particular, for girls.
Over 1.6 million students aged 11 to 17 years old from 146 countries, that is 81.3% of world’ schooled teens, were surveyed and asked about their physical activity habits. This report release gives us the perfect opportunity to review the health benefits associated with physical activity, the importance of fostering healthy habits and physical activity in adolescence and familiarize ourselves with the World Health Organization's (WHO) current recommendations for physical activity for teens.
Physical inactivity is the fourth leading cause of global mortality. The health consequences of a sedentary lifestyle and physical inactivity include increased risk of cardio-vascular diseases, cancers, type 2 diabetes, hypertension, osteoporosis and obesity. By contrast, there is ever growing evidence of lifelong health benefits of physical activity. In addition, physical activity has been proved to have a positive impact on anxiety and other mood disorders. It has also been associated with reduced risk-taking behaviors, smoking and alcohol consumption. Furthermore, there are specific additional benefits for teens in terms of how well they do in school and how they relate to others in social situations: Overall, physically active students achieve better grades and school attendance and display overall better classroom behaviors. Higher physical activity and physical fitness levels are associated with improved cognitive performance such as memory, attention and reasoning. Lastly, sports and any organized or non-organized physical activity can provide many opportunities for meeting new friends, practicing social skills, building self-confidence and leadership skills. Playing sports or belonging to a team is also a great way for teens to get to know each other.
What about American teens?
According to the Lancet publication, 72% of American students did not meet the recommendations in 2016. While this number is still too high, we are doing better than most countries. Possible reasons for our performance include the prevalence and quality of physical education in our schools, the constant presence of sports in our media, numerous opportunities to join sports club, as well as our strong cultural interest in sports, exemplified by the existence of national sports like baseball and American football. However, while physical inactivity decreased overall among American teens since the last report in 2001, this trend is not seen among girls but only in boys. Girls reported physical inactivity significantly higher than boys in 2001 (80.7% for girls vs 70.9% for boys) and have since made no progress at all, unlike their male counterparts, with physical inactivity at 80.5% for girls vs 64% for boys in 2016. While this gender difference is not specific to the US and can be observed in all but 4 countries surveyed, this causes questions: Are there more sport opportunities (think clubs) for boys than girls? Is being physically active viewed as a more desirable quality for boys (think how we used to call sporty girls “tomboys)? Can you think of other possible explanations? According to the CDC, these gender differences in physical activity behavior become apparent during the transition to adolescence. Adolescence is when the amount of physical activity done by girls tends to decrease dramatically compared to that of boys, and this trend is carried over into adulthood. Thus, girls may need additional support and encouragement to maintain an adequate amount of physical activity. Bridging this gender gap will be essential if we want healthier adults and for the next generations.
As we can see, while overall physical activity trends among American students are encouraging, we cannot rest on our relative achievements. Well over two thirds of our teens are still insufficiently physically active. Not only are they missing out on a wide range of immediate academic, social and health benefits but they are also laying the ground for chronic disease later in life. The biological processes leading to cardio-vascular disease and cancer take years and even decades. Because many health behaviors and patterns are formed during childhood and physical activity habits tends to decline during adolescence, it is important to encourage all teens, and especially girls, to keep being physically active so that health benefits can be maintained into adulthood. By contrast, research suggests that adverse health outcome of physical inactivity also tend to carry over into adulthood. For example, as many as 50 to 70% of obese children and teens will become obese adults.
What can you do?
In the United States, the Center for Disease Control and Prevention (CDC) supports and promotes WHO’s recommendations. WHO’s recommendation is for 60 min of daily physical activity of moderate to vigorous intensity
- Children and adolescents aged 5 to 17 years old should accumulate at least 60 minutes of moderate - to vigorous-intensity physical activity daily. This means that this goal of 60 minutes per day can be broken down into multiple shorter bouts spread throughout the day, for example 2 sessions of 30 minutes, if a minimum of 60 minutes daily is achieved.
- The more, the better: Any additional time spent being physically active (beyond the recommended daily 60 minutes) yields health benefits.
- Most of the daily physical activity should be aerobic. Aerobic (also known as cardio) literally means ‘exercise that requires oxygen’. So, it refers to any light to moderate physical activity that can be sustained for an extended period of time such as walking, running, cycling, rope jumping, dancing. However, vigorous higher intensity activities should be incorporated at least 3 times per week, including muscle-strengthening and bone-strengthening activities. The former focuses on muscles doing more work than usual during activities of daily life for muscle strength. The latter produce force on the bones which stimulates its growth and strength. The force is usually produced by impact with the ground, for example when running and jumping.
These recommendations apply to all healthy children aged 5–17 years乐动体育注册, unless specific medical conditions suggest otherwise, regardless of gender, race, and ethnicity.
Don’t let disability be a barrier!乐动体育注册 While the type and amount of physical activity should be discussed and adapted accordingly with their healthcare provider, these recommendations apply to children and adolescents with disabilities as well.
It is never too late!乐动体育注册 For some children and teens who are currently not doing any physical activity, it might feel intimidating or even dangerous to start from scratch. Remember that, by and large, the health benefits of physical activity are likely to outweigh any risks. Keep in mind that any amount of physical activity (even below current recommendation) will bring more health benefits than doing none at all. Starting with small amounts of light physical activity and gradually increasing duration, frequency and intensity is very safe.
More Information and Resources
Penn State Extension Motivators to Reach Your Health and Fitness Goals
- Guthold R, Stevens GA, Riley LM, Bull FC. Articles . Lancet child Adolesc Heal [Internet]. 2019;4642(19):1–13.
- Kumar B, Robinson R, Till S. . Clin Med (Northfield Il) [Internet]. 2015 Jun 1;15(3):267–72.
- Early W, Obesity C, Initiative P, Start H, Taken S, Activity P, et al. Physical Activity Guidelines for Americans. 2013;(202):56–63.
- WHO. Physical-Activity-Recommendations-5-17 Years. Who. 2011;1(1):1–2.