
Exercise plays an important role in building bone in childhood and adolescence, maintaining bone before 50, and slowing down bone loss after 50. But exercises are not equal.
The best exercises are those with impact (running, sprinting, jumping) or resistance (squats, pushups, rock climbing).
Current research indicates that non-weight bearing exercise like cycling and swimming and light impact exercise like slow walking are not enough.
Yoga and Pilates
There are not many yoga or Pilates bone density studies. However, knowing that resistance exercise is effective, we can logically assume that some aspects of yoga and Pilates are beneficial.
Standing yoga poses, like the warrior and transitional lunges, can build leg and hip bones. One-legged poses, like tree, improve balance. Poses like reverse plank and upward and downward dog should strengthen wrist and forearm bones.
All yoga and Pilates exercises that require lifting of the legs or upper torso in the supine or prone (face up and face down) positions may build bone density in the lumbar spine.
Pilates machines that use the resistance of springs are similar to gym machines using cables.
Tai Chi
This gentle exercise improves balance and leg strength. Studies found that people who did tai chi reduced their rate of falling by 50 percent. When they do fall, their rate of fractures is much less. Do tai chi once or twice a week for at least 15 minutes.
Jumping
Skipping rope, jumping jacks and vertical jumps are effective bone-builders. Skip rope for at least 15 minutes 3-5 times a week. You only need two minutes a day for jumping jacks and vertical jumps. Do several 15-30 second jumps and rest in between.
Racquet sports
A Finnish study found that squash players and weight lifters had the highest bone mineral densities. Squash, tennis and badminton are stop-and-go sports with rapid multidirectional changes—all beneficial to bone strengthening.
Gardening
Growing flowers can help build bone but only if you actually shovel, rake and weed. Telling your gardener what to do doesn’t count. A University of Arkansas study found that women older than 50 who went to the gym or who gardened had lower rates of osteoporosis.
Rowing
In an Oregon University study, postmenopausal women who rowed competitively for one year experienced a 6-percent greater increase in spine density than women who did not row but who were physically active.
Aerobic dance
Women who did a 45-minute step aerobics class three times a week for six months experienced a 3-percent increase in bone density in their spines, legs and heels.
Researchers at Texas A&M University say step aerobics adds the extra challenge of changes in direction and speed that stimulate the bones even better than skipping rope and jogging that only offer impact.
A British study found that high-impact aerobics (aerobics with hops, skips, and jumps) improved the hipbone density of postmenopausal women and men over 50.
Walking
A Johns Hopkins Hospital study found that light-intensity walking does not strengthen bones. Brisk walking delivers a higher impact than slow walking.
Brisk walking (as if you are late for an appointment) for 30 minutes four days a week can help reduce bone loss before and after menopause. A study found that women who regularly walked 7.5 miles a week lost bone at a slower rate (four to seven years longer) than women who did not walk.
For people at risk of falling, lifting weights is a better and safer alternative than walking.
Cycling
Off-road bikers have above average bone density while street cyclists have slightly below average bone density, according to a study published in the journal Bone. The jarring, bouncing and vibration on rough roads is a stimulation that builds bone.
If street cycling or spinning is your only exercise, add weight training or impact exercise to your regimen. A 2003 study found that male cyclists (aged 40-60) who had been cycling 12.2 hours a week for 20 years had bones that were 10 percent less dense than active non-cycling men their age. Of the 27 cyclists, 17 had moderate bone loss or osteopenia while four had severe bone loss or osteoporosis.
Profuse sweating from intense cycling may contribute to bone loss. Evidence suggests an hour of intense endurance training can result in a loss of 200 mg of calcium. A 1996 study attributed bone thinning among college basketball players to prolific sweating.
Swimming
Many studies found that swimmers had lower bone densities than athletes in weight-bearing sports and lower or similar bone densities as non-athletes. The results apply to males and females—prepuberty age, adolescents and adults. Swimming is not reputed to increase bone mineral density.
But most studies used dual X-ray absorptiometry (DXA), a two-dimensional measure highly influenced by body size.
Male water polo players and weightlifters assessed using quantitative computed tomography (QCT) had similar bone densities.
Rat studies found that swimming improved bone elasticity and structural strength—properties that could only be seen with quantitative ultrasound (QUS).
Perhaps when more human studies use QUS, swimming will shake off its bad reputation. In the meantime, swimmers should cross-train with weights or impact exercise.
Sources: National Osteoporosis Foundation, American College of Sports Medicine, American Council on Exercise, Harvard School of Public Health













