So taking a closer look at the exercise component, how exactly does exercise help your bones? In order to stimulate bones to increase their density, exercise must "stress" the bone during weight-bearing activities or muscle contraction. The National Osteoporosis Foundation defines weight-bearing as exercise in which bones and muscles work against gravity as the feet and legs bear the body's weight. Examples of weight bearing activities include walking, jogging, dancing, aerobic/step classes and racquet sports. As well, activities such as gymnastics, basketball and volleyball are even more effective due to the inconsistent high impact landing patterns that place stress on the bone, in contrast to running for example, which is a consistent repeated landing pattern. So add some bounding and hopping to your runs for a bone building blast!

Resistance training is also a very effective modality to help increase or maintain bone density, due to the stress placed upon the bone as the muscles shorten during contraction. The contraction causes a slight "bending" of the bone where the muscle is attached, and stimulates increases in bone density. The exact mechanism is unclear, but may involve an electrical current produced by the stress that activates osteoblasts (bone forming cells) to increase mineralization.

To maximize the bone building effects, resistance and weight-bearing exercises should be supported by adequate calcium & vitamin D intake, necessary for bone formation. If your diet does not include dairy products, or you consume less than 3 servings of milk, cheese or yogurt daily, you should include calcium-fortified products such as soy-milk or fortified orange juice. A supplement is usually necessary for individuals whose dairy intake is low or none.

Interested in more? Get your nutritional competitive edge - book an appointment! Nanci S. Guest BSc, MSc (c), Sport Nutritionist - reach her at www.powerplayweb.com

Nanci S. Guest is a certified personal trainer & nutritionist, and is completing her Master of Science degree in nutrition this June. She owns "Power Play: Nutrition, Fitness, Performance" in Vancouver, BC, and for the past 8 years she has been providing individuals, sports teams & the community with nutritional consulting & personal training services, as well as research services, seminars and article writing for local & national publications.

Her specialization is sports nutrition, catering to a variety of athletes of all levels. Some of her elite athletic clientele include members of the Vancouver Canucks, the Vancouver Giants & the BC Lions, the Canadian National Freestyle Ski Team, Iron Man participants, athletic teams from BC high schools and universities, and a variety of other provincial and national team members. Nanci can be reached at www.powerplayweb.com and by email at nanci@powerplayweb.com.