and Physical Activity
L. Mullen, CSCS
Each day presents itself as an opportunity to enhance your health and fitness level by
engaging in physical activity. If you choose to put off until "tomorrow," you
miss that opportunity: another check mark is added in the "sedentary day" column
and a withdrawal is made from your health savings account. If, however, you choose to be
physically active, you make an investment in your health account.
This investment is especially important in combating age-related declines in
metabolism, muscle mass and bone density. With regard to osteoporosis, many older people,
especially women, have bankrupt health accounts because they didnt invest in their
health when they were younger by exercising regularly and eating properly.
Osteoporosis is caused by the loss of bone mass, creating thin, porous bones
which are fragile and easily fractured. Fractures typically occur in the hip, spine and
wrist. A hip fracture usually requires hospitalization, can limit a person's ability to
walk unassisted and may cause permanent disability or even death. Fractures of the
vertebra in the spine also have serious consequences, including loss of height, severe
back pain and deformity.
Bone isnt a lifeless structure but a complex, living tissue.
It has the capacity for growth and regeneration if damaged and is sensitive to the forces
it experiences. Bone tissue is constantly undergoing remodeling in which old bone is
removed and new bone is formed. After age 35, however, bones begin to break down faster
than new bone can be formed. In women, bone loss accelerates after menopause because the
ovaries stop producing estrogen, the hormone that protects against bone loss.
The critical years for building bone are before the age of 20. Some experts
believe that young women can increase their bone mass by as much as 20 percent - a
critical factor in protecting against osteoporosis. In order to stimulate increases in
bone density, mothers should provide their daughters with adequate intakes of calcium and
vitamin D and make sure they engage in weight-bearing physical activity.
Deposits into your health savings account before the age of 20 are the most
beneficial in building up your principal (bone mass). However, if you stop making deposits
and become sedentary, youre essentially making withdrawals which could lead to
osteoporosis. Both building and maintaining bone mass is the best defense against
developing this disease.
A Mile A Day Slows Bone Loss
According to the U.S. Dept. of Agricultural Research Service women who walk a mile or more
a day lose bone more slowly than women who do little walking. The researchers found that
the mile-per-day walkers had 7% more bone in their legs than the women who walked less
than a mile a day. Also, the exercisers achieved cardiovascular benefits.
Exercise that forces you to work against gravity (weight-bearing exercises) such
as jogging, stair climbing, hiking, aerobic dance and racquet sports are beneficial in
slowing the rate of bone loss. Remember, however, the benefits of exercise last only as
long as you maintain the program.
Strength Training Adds Bone Mass
Until recently, it was thought that after the age of 30, exercise could only
reduce the rate of bone loss. However, the latest research performed at the Human
Nutrition Research Center on Aging at Tufts University indicates that strength training at
any age can actually add bone, not just slow its loss. Strength training works by applying
a force to the bone that creates a stimulus for new bone formation.
In the study, women aged 50 to 70 strength trained twice a week for a year at
which time the bone density of their hips and spine was measured. They added about 1%,
while the sedentary group had lost about 2.5% bone density. As might be expected, the
exercisers also significantly increased their muscle strength.
Strength training can be done anywhere using equipment as simple as dumbbells,
rubber tubing and even your own body weight. The American College of Sports Medicine
(ACSM) currently recommends strength-training exercise be a component of a well-rounded
program for all healthy adults. The ACSMs recommendation is to perform 8-10
exercises 2-3 times a week, with at least one day of rest between training. One set of
8-12 repetitions per exercise is recommended for general strength training benefits for
people under age 50, which will take about 30 minutes to perform. One set of 10-15 reps
(more reps performed at a decreased intensity) is recommended for people over 50 or for
those with arthritis, previous injuries, or high blood pressure .(If you have any medical
condition get your physician's approval before starting a strength training program.)
Remember, building strong bones, especially before the age of 20, can be the
best defense against developing osteoporosis and that a healthy lifestyle can be
critically important for keeping bones strong. Whatever your age, you need to make
deposits into your health savings account today in order to prevent osteoporosis later in
life and enjoy an active, physically independent lifestyle.
band kits (a simple way to strength train) and other exercise
products suitable for older adults at Simple