Physical activity among children and teens is lower than previously thought, and, in another surprise finding, young adults after the age of 20 show the only increases in activity over the lifespan, suggests a study conducted by researchers from the Johns Hopkins Bloomberg School of Public Health. Activity levels at the end of adolescence were alarmingly low, and by age 19, they were comparable to 60-year-olds. The study confirmed that recommended guidelines were not being met. For instance, the World Health Organization (WHO) recommends at least 60 minutes of moderate-to-vigorous physical activity a day for children ages five to 17 years. The study found that more than 25 percent of boys and 50 percent of girls ages six to 11 and more than 50 percent of male and 75 percent of female adolescents ages 12 to 19 had not met the WHO recommendation.
— source jhsph.edu 2017-08-15