These Web Extra sidebars accompany the Inner IDEA column, “Update: Are Pilates and Yoga Right for Clients With Low Bone Density?” by Sherri Betz, PT, which appears in September 2015 IDEA Fitness Journal.

Web Extra #1: Building Bone: Concepts and Controversies

The positive role that resistance training can play in building and maintaining bone and muscle tissue is well established. But how do other types of exercise affect bone? Recent research findings are sobering.


Walking does not build bone. Shocked? Doesn’t everyone say, “I don’t understand how I got osteoporosis. I walk. . . .” Most studies show that walking either doesn’t affect bone or may at best prevent bone loss (Martyn-St. James & Carroll 2008).

On the other hand, gait speed has been touted as the sixth vital sign and an excellent indicator of overall health, well-being and longevity (Duncan 2009). Walking is great for cardiovascular health and fall prevention, and certainly should not be discontinued just because it is not effective in building bone!


Running less than 80 kilometers a week has a positive effect on bone mineral density of the proximal femur (MacKelvie et al. 2000). With running, however, more is not always better. MacDougall and others (1992) found that bone density in the lower extremities was significantly greater for study participants who ran 15–20 miles a week than it was for the inactive control group and for those who ran 5–10 miles a week. With mileage greater than 20 miles week, BMD of the lower legs showed no further increase and, in fact, tended to decrease: For those running 60–75 miles a week, BMD was similar to that of control group members.


Campion found BMD in the femoral neck was 18% lower in 30 professional road cyclists than it was in 30 young healthy males even with similar calcium intake (Campion et al. 2010). Cyclists are seven times more likely to have osteopenia of the spine than runners, controlling for age, body weight, and bone-loading history (Rector et al. 2008). Of the cyclists in Rector’s 2008 study, 63% had osteopenia of the spine or hip, compared with 19% of runners (Rector et al. 2008). Olmedillas et al (2012) conducted a systematic review of cycling and bone health relationships and found that two-thirds of professional and master road cyclists are osteopenic.

Water Exercise

Moreira et al (2014) conducted a review of many types of exercise performed by postmenopausal women and concluded in a well-organized summary that aerobic non-weight-bearing sports such as swimming and cycling usually lead to lower BMD than impact sports do.

One study by Bravo and colleagues showed that 70 women who exercised vigorously in waist-high water three times per week had a significant decrease in the BMD of the vertebral bodies of the spine and no change in the femoral neck after a 12-month program (Bravo et al. 2007).

Murtezani et al. (2014) compared land exercise and aquatic exercise in 58 osteoporotic postmenopausal women, aged 50–70, and saw significant improvement in muscle strength, flexibility, gait time, pain and bone density in the land exercisers. From preseason to postseason, water polo players lost bone density in the legs and gained it in the arms (Kavouras et al. 2006).

Summary: Endurance and Bone Health

For optimal fitness, endurance activity should be performed at least 3 times per week and strength training 2–3 times per week. For preservation of bone health, however, don’t overdo endurance activities and try to choose ones that you do on your feet!

Web Extra #2: Spinal Flexion in Yoga: Fracture Cases

Sinaki, who with Mikkelsen conducted the hallmark study on flexion exercise and risk of vertebral fracture (Sinaki & Mikkelsen 1984, summarized in “Modifying Pilates for Clients With Osteoporosis”), has reported three cases of vertebral fractures following extreme spinal flexion moves in yoga practice (Sinaki 2013):

Case #1: Healthy female, 87 years old, spine T-score -1.4. Client experienced severe back pain after performing Plow pose under instructor supervision. Spinal radiographs showed she had sustained a vertebral compression fracture (VCF) at the second lumbar vertebral body.

Case #2: Healthy female, 61 years old, spine T-score -1.8. Client experienced excruciating back pain while performing Seated Forward Fold and Plow. She had severe pain initially, but this decreased later. Spinal radiographs showed osteopenia, a new VCF of the superior end plate of T4, spondylolysis of L5 with grade 2 spondylolisthesis of L5 on the sacrum, and severe degenerative disk disease at the lumbosacral interspace.

Case #3: Female with degenerative joint disease of C-spine, 70 years old, spine T-score -1.3. Patient complained of severe, persistent neck and upper-back pain. At the suggestion of her daughter, the client began an independent yoga home program. After she had performed yoga—including Bridge and Plow—for about 10 weeks, neck pain, headaches and upper-back pain developed and persisted over the next 2.5 months. Radiographic examination showed she had sustained VCFs at T8 and T9 vertebral bodies (Sinaki 2013).

Web Extra #3: Top 10 Assessment Tests for Bone Health

  • Standing height (Siminoski et al. 2005, 2006).
  • Kyphosis as measured by occiput to wall distance (OWD)*: The back of the head with eyes level measuring greater than 7 centimeters away from the wall is strongly predictive of thoracic VCF (Antonelli-Incalzi et al. 2007).
  • Rib-to-pelvis distance: Less than 2 fingers of distance between the 10th rib and the iliac crest at the axillary line is predictive of lumbar compression fracture (Siminoski et al. 2003).
  • Functional reach (indicates fall risk): Can the client reach at least 10 inches forward? (Duncan et al. 1990).
  • Prone hip extension: Indicates gluteus maximus strength and hip mobility.
  • Supine to Sit test.
  • Floor to Stand test.
  • Single-leg standing balance.
  • TUG: Timed Up & Go: Tests gait speed and fall risk.
  • Sit to Stand test:
    –hip hinge/spine alignment?
    –use of upper-extremity assist?
    –leg alignment?

* Thoracic kyphosis can be measured many ways: OWD, Block System (client is supine with eyes looking straight upward, and measured blocks are placed under the head to determine the distance from head to floor), Kyphometer, Flexicurve Ruler or X-ray Cobb Angle Measurement. Movement teachers can easily use the OWD or Block System to measure progress in reducing kyphotic curvature.

References will be available when the main article (“Update: Are Pilates and Yoga Right for Clients With Low Bone Density?” by Sherri Betz, PT) appears on next month.