Effects of High-Intensity Interval Training on Bone Health in Hong Kong Older Women

Osteoporosis is an age-related disease, characterized by a decreased bone mass and an increased risk of fragility fractures. Osteoporosis leads to increasing mortality, disabilities, morbidity of chronic pain, and the cost of health and social care, as well as decreasing the quality of life from reduced independence and hindered physical, mental, and social well-being.

A recent review and meta-analysis, investigating the association between physical activity and osteoporosis prevention in elderly people, indicated that the traditional exercise interventions (i.e., resistance training) were undertaken for 60+ mins, 2-3 times/week for 7+ months. However, participation rates remain low in these exercise programs among older adults, in part due to a need for specialized equipment and correct techniques to prevent injury. In addition, low motivation and associated compliance with such conventional exercise is problematic among older adults.

Considering there is little evidence of HIIT benefits related to older women with osteopenia, the current study aims to evaluate the effectiveness of a 24-week HIIT intervention on bone mineral density, bone turnover markers and other health-related outcomes among Hong Kong Chinese older women.

The study will be a randomized controlled trial (RCT) with two groups and three times repeated measures. Data will be collected in a pretest, post-test, and six months after the intervention. The eligible participants will be randomly distributed into one of two groups in a ratio of 1:1. The participants recruited and meeting the screening criteria will receive a 24-week HIIT intervention or recreation workshop. The intervention effects will be evaluated on bone mineral density, bone turnover markers, physical fitness, fear of falling, and quality of life.

Eligibility Criteria:
Inclusion Criteria:

* • 60 to 74 years at the start date of the project

  * diagnosed with osteopenia by DXA scan screening with a BMD at the femoral neck or total hip or lumbar spine between -1 and -2.5 SD T-score below the average values
  * Passing the PAR-Q plus screening or with the physician's approval for readiness to participate in high-intensity exercise
  * Above the average level of 2-mins stepping showing competent aerobic fitness
  * No restriction on physical mobility
  * No cognitive impairment, as determined by the Chinese version of the Mini-Mental Status Examination (i.e., score \< 24)
  * No previous substantial experiences in practicing HIIT. The written informed consent form will be collected from each participant

Exclusion Criteria:

* • Severe chronic disease restricting high-intensity exercise

  * Having cognition impairment regarded by specialists
  * checked through medical records at HA Go app platform in the past 6 months, have concurrent medical conditions (e.g., thyrotoxicosis or hyperparathyroidism, Paget's disease, renal disease, diabetes, knee or hip osteoarthritis) and use medications (e.g., corticosteroids, estrogen, thyroxine, thiazide diuretics, or antiretroviral agents) known to affect bone metabolism during past 2 years
  * any condition with osteoporosis, osteoporotic fractures
  * current smoker
  * alcohol 3 or more units per day.