Analyze This: Most teen girls don’t meet guidelines for daily exercise | Science News for Students

Analyze This: Most teen girls don’t meet guidelines for daily exercise

African-American boys tend to be the most active
Jan 8, 2019 — 6:30 am EST
a photo fo several teen girls playing basketball on an indoor court

Playing a sport like basketball is a great way to get exercise, but many teens aren’t getting the recommended daily amount of healthful activity.

monkeybusinessimages/iStockphoto

An active lifestyle is important for health. Making it habit, however, can be hard for some teens. Certain groups seem to do better than others at making exercise part of their regular routines. Those needing the most improvement, here: girls!

Sarah Armstrong studies human health and behavior at Duke University’s clinical research institute in Durham, N.C. She and her colleagues wanted to better understand how active teens and young adults were. Teens should get at least 60 minutes of moderate to vigorous exercise each day, the U.S. Department of Health and Human Services recommends. This might include walking briskly, bicycling or playing a sport. Armstrong’s group wanted to know how many teens met that goal.

The researchers started with data from the National Health and Nutrition Examination Survey (NHANES). It collects information about the health, habits and diet of a representative cross-section of the U.S. population. The team focused on kids 12 to 17. It noted how much activity each said they got each day.

Many teens reported being fairly sedentary. Girls tended to be least active. Boys were generally more active. Overall, African-American boys were most active.

These data could guide future research about the role of physical activity in teen health. They might also suggest which segments of the teen population to target with programs aimed at getting them to move their bodies more.

a graph showing how much activity various groups of teens got on a daily basis
Each bar in this chart shows the time range, in minutes, of daily physical activity reported by each group. The number in the middle of each bar is the mean duration of exercise each day that group. The vertical yellow line marks the recommended daily activity level for teens.
Source: S. Armstrong MD et al/Jama Pediatrics; L. Steenblik Hwang

Click here for a larger chart.

Data Dive: 

  1. The U.S. Department of Health and Human Services recommends that teens get at least 60 minutes of moderate to vigorous physical activity each day.
    1. Examine the chart (larger version here). Which groups met this requirement?
    2. Which groups averaged less than 60 minutes of activity per day?
       
  2. Estimate how much time you spend being physically active each day.
     
  3. Look at the data for your group (gender and ethnicity). How does this compare with how much daily activity you report getting? How does this compare with what the government recommends?
     
  4. Are there other variables that might change how active a teen can be that aren’t explained in these data? Explain.
     
  5. By ethnic group, calculate how much more exercise the boys were getting compared to girls (figure it on a percent basis). Show your work.
  1. From the graph above, you can’t know how the students got their physical activity. It could be useful in understanding when, where and why they moved as much or as little as they reported. So, if you could talk to the students who took part in this survey, what more would you like to know about the type and amount of physical activity they were getting? Craft at least three additional questions that you would have had the NHANES survey ask them.

Beyond the Data:

Keep track of your daily physical activity for a week. Then compare your initial estimate (from question 2 above) with the data you gathered. Was there a day that you forgot to record how active you were? Do you think you under- or overestimated how active you were?
 


Analyze This! explores science through data, graphs, visualizations and more. Have a comment or a suggestion for a future post? Send an email to sns@sciencenews.org.

Power Words

(more about Power Words)

average     (in science) A term for the arithmetic mean, which is the sum of a group of numbers that is then divided by the size of the group.

behavior     The way something, often a person or other organism, acts towards others, or conducts itself.

clinical     (in medicine) A term that refers to diagnoses, treatments or experiments involving people.

colleague     Someone who works with another; a co-worker or team member.

cross-section     A term for the view of some three-dimensional solid as it would appear if a knife had cut through the structure, separated it in two, and then one of those pieces was now looked at edge-on from one of the cut sides.

data     Facts and/or statistics collected together for analysis but not necessarily organized in a way that gives them meaning. For digital information (the type stored by computers), those data typically are numbers stored in a binary code, portrayed as strings of zeros and ones.

ethnicity     (adj. ethnic) The background of an individual based on cultural practices that tend to be associated with religion, country (or region) of origin, politics or some mix of these.

gender     The attitudes, feelings, and behaviors that a given culture associates with a person’s biological sex. Behavior that is compatible with cultural expectations is referred to as being the norm. Behaviors that are incompatible with these expectations are described as non-conforming.

National Health and Nutrition Examination Survey (or NHANES)    A long-running program (begun in the early 1960s), which has been designed to assess the health and nutritional status of adults and children in the United States. NHANES combines both physical (medical) examinations and interviews. It’s run by the National Center for Health Statistics, which is part of the U.S. Centers for Disease Control and Prevention. Each year, the program surveys another 5,000 people who have been chosen to be representative of all ages and races, and of people living throughout the nation.

National Health and Nutrition Examination Survey     (or NHANES) A long-running program (begun in the early 1960s), which has been designed to assess the health and nutritional status of adults and children in the United States. NHANES combines both physical (medical) examinations and interviews. It’s run by the National Center for Health Statistics, which is part of the U.S. Centers for Disease Control and Prevention. Each year, the program surveys another 5,000 people who have been chosen to be representative of all ages and races, and of people living throughout the nation.

range     The full extent or distribution of something. For instance, a plant or animal’s range is the area over which it naturally exists. (in math or for measurements) The extent to which variation in values is possible. Also, the distance within which something can be reached or perceived.

sedentary     Not physically active; an adjective for activities done largely while sitting.

survey     (v.) To ask questions that glean data on the opinions, practices (such as dining or sleeping habits), knowledge or skills of a broad range of people. Researchers select the number and types of people questioned in hopes that the answers these individuals give will be representative of others who are their age, belong to the same ethnic group or live in the same region. (n.) The list of questions that will be offered to glean those data.

variable     (in mathematics) A letter used in a mathematical expression that may take on different values. (in experiments) A factor that can be changed, especially one allowed to change in a scientific experiment. For instance, when researchers measure how much insecticide it might take to kill a fly, they might change the dose or the age at which the insect is exposed. Both the dose and age would be variables in this experiment.

vertical     A term for the direction of a line or plane that runs up and down, as the vertical post for a streetlight does. It’s the opposite of horizontal, which would run parallel to the ground.