There are so many reasons why children need to move. But today, more than ever, the primary reason may be movement’s contribution to their physical fitness. Word of the childhood obesity crisis is everywhere: magazines, newspapers, television, and radio talk shows. Even so, it’s sometimes difficult to take it all seriously. How can we be experiencing a childhood obesity epidemic? Worse yet, how can we be using words like heart disease in relation to young children?
Unfortunately, we are. Obesity among children is increasing faster than among adults. In 2000, 22 percent of U.S. preschoolers were overweight and 10 percent clinically obese (Pica, 2003). Obesity is also now seen among infants and toddlers as well (Huettig, Sanborn, DiMarco, Popejoy, & Rich, 2004).
Studies have shown that 40 percent of children ages five to eight have at least one heart disease risk factor, including hypertension (Bar-Or et al., 1988; Berenson, 1980; Ross, Pate, Lohman, & Christenson, 1987). The first signs of arteriosclerosis (hardening of the arteries) are now appearing at age five (Institute for Aerobic Research, 1987). A recent Centers for Disease Control (CDC) presentation contends that American children born in the year 2000 face a one-in-three chance of developing Type 2 diabetes (formerly known as adult-onset diabetes because it was previously nonexistent among the young). And a number of experts believe this may be the first generation of children who will not outlive their parents.
A Different Kind of Energy Crisis
Why is this happening? The formula is pretty straightforward: energy in/energy out. This is the phrase nutritionists use to describe the intended balance between calories consumed and calories burned. If the level of physical activity isn’t great enough to burn the amount of calories taken in, weight increases. If this imbalance continues, obesity may result.
Given our fondness for fast food and our tendency to “super size,” it’s easy to imagine that caloric intake is the crux of the obesity problem. And certainly it is part of the problem. But studies both here and abroad have indicated the greater problem lies with the second half of the equation: energy out. Children simply aren’t moving enough!
It’s been estimated that between the ages of two and 17, American children spend an average of three years of their waking lives watching TV (Cooper, 1999). That’s the equivalent of more than 15,000 hours in front of the set (and this doesn’t even include time spent watching videos, playing video games, or using the computer)—as compared with 12,000 hours spent in a classroom. The end result? A minimum of 27,000 hours—more than six years of their young lives.
The Importance of Physical Activity
Although most of the research has been conducted on the relationship between physical activity and adult health, there’s now enough evidence to show physical activity causes health benefits for children and adolescents as well. Improved aerobic endurance, muscle growth, muscular strength, motor coordination, and growth stimulation of the heart, lungs, and other vital organs are among these benefits.
Given these rewards, it’s important that teachers and families work together to help children establish healthy eating patterns and healthy physical activity habits during the stage when important habits are formed: early childhood! Also, the goal should not only be to ward off ill health but to promote good health and physical fitness in all children.
The Five Fitness Factors
To help children along the path to fitness, it’s helpful to have some understanding of the components involved. It’s also important to realize that the emphasis should be placed on the health-related, as opposed to the skill-related, components of fitness. Descriptions of the five health-related components of physical fitness and some sample activities follow.
Cardiovascular Endurance. The ability of the heart and lungs to supply oxygen and nutrients to the muscles defines cardiovascular endurance. In simple terms someone with great cardiovascular endurance has a strong heart—one that actually grows in size and pumps more blood with every beat, resulting in a lower heart rate. As you can imagine, this can happen only when an individual exercises regularly. Typically it’s aerobic exercise that improves cardiovascular fitness, but where children are concerned we can’t think of “aerobics” in the same way that we do for adults.
Children are not made for long, uninterrupted periods of strenuous activity. So expecting them to jog, walk briskly, or follow an exercise video for 20 to 30 minutes, particularly before the age of six, is not only unrealistic but could be damaging. Rather, when we consider developmentally appropriate aerobic activities for children, we should be thinking along the lines of moderate to vigorous play and movement. Walking, marching, playing tag, dancing to music, and jumping rope all fall under the heading of moderate to vigorous exercise for children. In other words, it’s anything that keeps the child moving continuously, sometimes strenuously and sometimes less so.
Muscular Strength. Muscular strength is described as the ability to exert force with a single maximum effort. Strong muscles are necessary not only for performing certain tasks, like throwing for distance, hanging and swinging, climbing, and carrying heavy books and groceries, but also for preventing injury and maintaining proper posture. An added bonus is that increasing muscle strength also increases strength in tendons, ligaments, and bones.
Strength training, also known as resistance or weight training, is the best way to build muscular strength. But here again, we must view things differently than if we were discussing adults. While there’s a lot of debate over the appropriateness of involving young children in strength training, there are some points on which the experts agree.
First, it’s never a good idea to modify an adult strength-training program for children. Adults’ bodies are fully developed; children’s are not. Adults have long attention spans and the motivation to endure the monotony of repetitive exercises; children do not. For these reasons the best “strength training” for children involves the use of their own weight in physical activities they’d be performing anyway, like jumping, playing tug-of-war, and pumping higher and higher on a swing.
Muscular Endurance. Muscular endurance is the muscles’ ability to continue contracting over an extended period of time. In other words, it’s about stamina. Landy and Burridge (1997) write: “Good muscular endurance gives you the ability to repeat a movement without getting tired or to hold a position or carry something for a long period of time without being fatigued. A child who has good muscular endurance will enjoy and have greater success in her daily work activities, in play, and in sporting and athletic competitions.”
Obviously, muscular endurance is tied to muscular strength; so many of the same kinds of activities and exercises benefit both. However, muscular endurance also depends on skill level. Children, by virtue of having fewer years of practice in most skills, will use the maximum force and contract more muscles than actually needed for the movement. Therefore, they won’t be able to last as long as a skilled mover.
Flexibility. Flexibility is the range of motion around joints. When people possess good flexibility, they can stretch to put something on a high shelf, bend to tie a shoe, or sit cross-legged without effort or aches and pains. They can swing a tennis racket or a golf club, perform a lay-up in basketball, or reach for a high fly without fear of muscle strain, sprain, or spasm.
If children are physically active, they’ll be flexible. But they should also be encouraged to work on their flexibility through gentle, static stretches that take a muscle just beyond its usual length (without pain!) and are held for at least 10 seconds.
Two no-no’s regarding stretching: First, children should work their own limbs through their range of motion; it’s extremely easy for an adult to stretch a child’s muscles and joints too far. Second, children should be warned against ballistic (bouncing) stretching. It can cause small tears in the muscle fibers and is not as effective as static stretching.
Body Composition. The final component of health-related fitness is body composition: the body’s makeup in terms of fat, muscle, tissue, and bone or the percentage of lean body tissue to fat.
Obviously, with childhood obesity becoming more of a problem as the years go by, much attention is focused on body composition right now. But weight alone is not a good indicator of body composition. Some children are simply large-boned. Also, muscle weighs more than fat. So it’s possible for two children to have the same weight but very different make-ups, one possessing very little fat and the other too much.
Research has shown that inactive preschool children were almost four times more likely to enter first grade with increased body fatness (Moore, 1995). Physical activity, of course, is the key to combating fat, with aerobic and muscle-strengthening movement making the largest contribution.
By ensuring our children stay active, we can combat obesity before it starts rather than once it’s upon them. We can also help guarantee they derive positive health benefits both as children and as adults.
Rae Pica is a children’s movement specialist and author of 14 books, including the text Experiences in Movement: Birth to Age Eight, Moving & Learning across the Curriculum, and Your Active Child, written for the parents of children birth to eight. She speaks on early childhood issues throughout North America. You can visit Rae at www.movingandlearning.com.
Bar-Or, O., Foreyt, J. Bouchard, C., Brownell, K.D., Dietz, W.H., Ravussin,E., et al. (1998). Physical activity, genetic, and nutritional considerations in childhood weight management. Medicine and Science in Sports and Exercise, 30(1), 2-10.
Cooper, K.H. (1999). Fit kids! Nashville, TN: Broadman & Holman.
Huettig, C.I., Sanborn, C.F., DiMarco, N., Popejoy, A., & Rich, S. (2004). The O generation: Our youngest children are at risk for obesity. Young Children, 59(2), 50-55.
Institute for Aerobic Research. (1987). Get fit. Dallas: Author. Landy, J., & Burridge, K. (1997). 50 simple things you can do to raise a child who is physically fit. New York: Macmillan.
Moore, L.L., Nguyen, U.D.T., & Rothman, K.J., et al. (1995). Preschool physical activity level and change in body fatness in young children. American Journal of Epidemiology, 142, 982-988.
Pica, R. (2003). Your active child: How to boost physical, emotional, and cognitive development through age-appropriate activity. New York: McGraw-Hill.