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The PACE Senior Study

We are currently seeking physically active women and men
for a research study on


PTH and Calcium Responses to Exercise (PACE) in Older Adults


Goal of the study: PACE Sr. is studying how the changes in blood calcium during exercise impact the bone response to exercise. Generally, exercise is good for bone health. However, some studies have shown that older adults do not always get the bone gains that we expect from exercise. This may happen because exercise causes calcium loss through the sweat. These losses go along with declines in blood calcium and increases in parathyroid hormone (PTH). PTH is the hormone that causes calcium to be released from bone. It is possible that the reduced bone gains in people who exercise a lot is related to this calcium loss during exercise. This study will study whether the amount of calcium lost through the sweat during exercise impacts blood calcium and markers of bone loss.

Outline of the study: The PACE Sr. EXP1 study includes two 1 hour vigorous walking sessions on a treadmill. After a pre-exercise meal with a known amount of calories and calcium, the exercise sessions will be done in either a warm (~80°) or a cool (~60°) room. The temperature for these sessions will be in random order and will be 1 month apart. The study will be held on the University of Colorado Anschutz Medical Campus.

Eligibility: To participate, you must be...

  • A woman or man in generally good health, age 60 - 80
  • Regularly walk for exercise and can walk for an hour at a time
  • Not taking medication for osteoporosis
  • No history of Diabetes or Cardiovascular Disease

Benefits: Eligible volunteers will recieve at no cost...

  • Information on their VO2 max (aerobic fitness)
  • Information on their body composition and bone density
  • Physical exam and basic blood chemistries

Volunteers will have a physical exam, bone density test, treadmill test, and blood tests to determine if they are eligible. These tests will be done at no charge. Volunteers will be compensated for their time.

Sarah Wherry, PhD, is the Principal Investigator of the PACE study. This study is funded through the Colorado Clinical and Translational Sciences Institute (CCTSI) and the Nutrition and Obesity Research Center. It is approved by the Colorado Multiple Institutional Review Board (protocol #15-0250).

If you are interested in participating in the PACE study, please contact Toby Wellington at 720-848-6376 or