How often do you exercise? The American Heart Association recommends that you do at least 30 minutes of moderate-intensity aerobic activity at least 5 days per week, or at least 25 minutes of vigorous aerobic activity at least 3 days per week, combined with weightlifting at least twice per week. Keeping your weight down and your heart healthy isn’t the only reason to exercise. Physical activity is important for building and maintaining bone mass. Humans add to their bone mineral density (BMD) until about age 40, so if you’re under that age, make sure you build, build, build! After 40, we start to steadily lose BMD. While all individuals are at risk for osteoporosis, women are particularly at risk because menopause causes potentially severe decreases in BMD.
The reason bone loss is such a concern in older populations is that lower BMD leads to an increased fracture risk, which can have potentially debilitating or even deadly consequences. Many of these fractures occur in individuals aged 65 or older, but fractures can occur at any age. Mortality within the first year after a hip fracture has been reported to be anywhere between 14-58%. Some studies have even shown that after hip fracture, women and men have a 5-fold and nearly 8-fold increase in the likelihood of death within the first 3 months of recovery compared to healthy individuals in the same age group!
The best way to prevent fractures in the future is to be highly active while BMD is still steadily increasing. If you’ve never been very active, now would be the time to start exercising, because you can maintain, or even increase, your bone mass through physical activity! Bone and muscle both work together to create movement; without muscle, the skeletal system is immobile, and without the skeletal system, muscles would have nothing to attach themselves to. Because muscles attach themselves to the bone, any movement that we make slightly tugs on the point of attachment. The more resistance there is, the more your muscles tug on the bone, triggering bone-building cells called osteoblasts to make that part of the bone stronger so that it can handle the extra pressure without causing you injury. Weight training is a great example of this mechanism! If you’re worried about not being able to lift heavy weight, don’t be. The level of difficulty of any given weight is dependent upon your body and fitness level, meaning that what may be easy for someone else’s muscles may give yours the right amount of resistance!
Remember, using exercise as a way to maintain BMD is dependent upon mechanical loading, so you need gravity to help put more pressure on your bones. Exercises that fit under this category include weight training, walking, hiking, jogging, climbing stairs, tennis, dancing, martial arts, and other weight-bearing physical activities. Exercises that will not improve or maintain BMD include both swimming and bicycling. Swimming and biking are great forms of cardiovascular exercise, and if you like to participate in them, then keep doing so! But make sure that you add some weight-bearing exercise, even if it’s just weight training twice per week.
Elizabeth Foley is an FSU Ph.D. Candidate in Nutrition and Food Science. Posts and blogs created by Elizabeth on the Wealth Meet Health community are for informational purposes only and are not meant to take the place of your relationship with a health professional. For personal health considerations, please consult a health professional directly.
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