Bone is living tissue. Bone-eroding cells called osteoclasts break down the bone and create small holes or cavities. Bone building cells called osteoblasts fill in the cavities with new bone. This is happening in our bodies all the time. But the building happens more at certain times in our lives.
The best bone building years are in our childhood and teen years. The skeleton reaches its strongest and thickest at about 16 years of age in girls and age 20 in boys. During our 20's, the cells that break down bone and the cells that build up bone work equally well. After our 30's, the cells that build bone do not work as hard. We can gradually begin to lose bone. Our bones become less strong and thick and we have a greater chance of developing osteoporosis as we get older.
How can we keep our bones strong throughout our lives?
Good nutrition and weight bearing exercise helps build bones and keep them strong and healthy. Bone building nutrients are calcium,
phosphorus, magnesium, protein and Vitamin D. Milk contains all of these nutrients and more. Weight bearing activities that strengthen bone are those that keep you on your feet. Activities that put your body's weight on your bones include: Football, Basketball, Field hockey, Racquetball, Soccer, Softball, Tennis, Volleyball, Golf, Running/jogging, Walking, Skiing, Aerobics, Gymnastics, Bowling, Hiking, In-line skating, Skateboarding, Snowboarding, Ice-skating, Hockey, Weight lifting, Cheerleading, Dancing, X Country Skiing, Martial Arts, Gardening, and Fishing.
An active lifestyle is part of a healthy lifestyle! The School Milk Foundation wants you to 
. Choosing to get the recommended daily servings of milk according to the Canada Food Guide will not only help us have strong bones and teeth it will give us
the energy to live an active lifestyle. The 15 essential nutrients found in milk give us the energy to be active everyday. Our slogan has two meanings! The first meaning is to choose milk and get the benefits of calcium, vitamin D and 13 other essential nutrients! But drinking milk also gives you the energy to stay active! You can Go dancing with Milk, Go skiing with Milk, Go Hiking with Milk and so much more. Milk is a super drink. It’s not only great for strong bones and teeth…it’s great for staying active and healthy. That’s why at The School Milk Foundation we embrace the slogans and 
. We know that by staying active and drinking 2-4 servings of milk each day you are staying healthy! So Go with Milk as part of a healthy active lifestyle!
Check out Canada's Physical Activity Guide at www.phac-aspc.gc.ca.