Fitness levels among kids are on the decline. Only one in four American schoolchildren gets an adequate amount of physical activity each day.

The number of overweight children is growing rapidly. Almost 37 percent of 6- to 11-year olds are obese.

Children should have at least 35 to 60 minutes of exercise each day. Without it, they can also miss their chance to build the strong bones they will need later in life.

Bones grow in size and strength during childhood. The bone mass gained through physical activity during childhood helps determine how healthy bones will be throughout life.

Through its campaign, "Get Up, Get Out, Get Moving!" the American Academy of Orthopaedic Surgeons (AAOS) reminds all kids to get active.

If you want strong bones, you have to use them. Bone is living tissue. It constantly reforms due to everyday stress placed upon it..

Physical activities work bones and muscles against gravity. This occurs with any weightbearing exercise. These activities cause bones to build more cells and become stronger. Everyone needs weightbearing exercise their whole life.

In addition to building stronger bones, regular physical activity also strengthens the heart and lungs. It lowers blood pressure, improves muscle strength and flexibility, reduces stress and depression, helps control weight, and improves sleep.

Childhood is a critical time for developing dietary habits that support bone health. Calcium is an important ingredient in healthy bones. Osteoporosis is a disease in later life that drains away bone's calcium.

Young people can help avoid osteoporosis by putting " deposits " of at least 1,300 mg of calcium each day into their " bone banks. " Calcium comes in dairy foods. These include milk; yogurt and cheese; and green, leafy vegetables, like spinach and broccoli.

Getting started is the toughest step in any exercise program. But, it is the most important. Slow and steady is the best way to begin to improve general fitness.

• Start with a variety of physical activities.
• Choose fun activities throughout the year.
• Take plenty of time to get ready. Warm ups and cool downs get your body ready to be active. Do walking, bending, and gentle stretching exercises. Flexibility exercises help avoid injuries.
• Sure and steady. Work toward fitness goals gradually.

• Plan to be active for 35 minutes each day. This can be broken up into shorter periods. Try 15 minutes of walking and 20 minutes of sports.
• Keep a daily activity log of minutes spent on activity. To build strength in legs, hips and the lower spine, try brisk walking, jogging, or hiking.
• Exercise can be fun. Try sports (like soccer, baseball, and basketball), dancing, step aerobics, stair climbing, tennis and other racquet sports, skiing, skating, karate, or bowling.

• Exercise can be fun! Put the emphasis on fun rather than on winning.
• Be a role model. Join children for a bike ride, a ball game, or a long walk.
• Use physical activity as a reward. Plan a family trip to the park.
• Make exercise part of everyone's daily routine. Chores such as raking leaves, painting, or walking the dog are great ways to increase physical activity.
• Schedule physical activity. Think about planning activities in 10- to 15-minute blocks of time throughout the day.
• Make it easy to be active. Plan indoor areas for physical activity.
• Make it fun to be active. Select toys and gifts that promote physical activity.