Impact Loading Effect on Bone Biomarkers in Female Runners
- Conditions
- Relative Energy Deficiency in Sport
- Interventions
- Behavioral: Impact Load ExercisesBehavioral: No Impact Load Exercises
- Registration Number
- NCT05341700
- Brief Summary
This study is a randomized, cross-over intervention study that will evaluate the effect of brief, high-impact loading exercises on biomarkers of bone metabolism in energy-restricted, eumenorrheic female runners. Volunteers will complete two, 5-day experimental conditions in a randomized order separated by one menstrual cycle (approximately 3 weeks). Experimental conditions will include a dietary intervention of energy intake equal to 30 kcal/kg of fat-free mass/d using controlled diets and an exercise intervention of daily treadmill running with or without an additional 50 impact loading exercises.
- Detailed Description
Many long-distance runners struggle to consume enough calories each day to match the number of calories they are burning during exercise and as part of daily living. Undereating for long periods of time is a serious concern because it can have negative effects on general health and sports performance. One of these long-term consequences is related to bone health. With undereating, bone can start to be broken down faster than it can be rebuilt. Even though it can take months, and even years, for bone to be seriously affected, this may lead to weak and brittle bones later in life, if it is left untreated. Typically, athletes are recommended to increase the number of calories they eat to prevent negative health concerns. However, not all athletes may be willing or able to increase their calories based on their performance goals, nutrition knowledge, or concerns with food security. This means that alternative strategies need to be investigated to counteract the negative effects of undereating on bone health. This study proposes to evaluate the effect of adding short bouts of high-impact jumping exercises to typical endurance training to promote healthy bone metabolism. This will specifically involve completing two phases of a supervised treadmill run and consuming a reduced-calorie diet (provided by the research team) on 5 consecutive days. In addition, one of the phases will include performing 5 sets of 10 jumping exercises on 5 consecutive days in addition to the treadmill run. Results of the study will serve as an important first step in helping exercise and medical professionals understand more about how to protect and manage the bone health of female long-distance runners.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 16
- Females runners with regular menstrual cycles, not using contraceptives
- Body Mass Index between 18.5-25.0 kg/m2
- Weight stable (+/- 2 kg) for 6 months
- Running volume of ≥30 miles per week, frequency of at least 5 days per week
- VO2max of ≥45 ml/kg/min
- Willing to consume provided meals and snacks
- Low Energy Availability in Females Questionnaire (LEAF-Q) score ≥8
- Menstrual disturbances measured by progesterone and self-report
- Using contraceptives (oral contraceptives, injections, intrauterine device, etc.)
- Low Bone Mineral Density (z-score < -1)
- Routine engagement in mechanical loading exercises
- History of fracture in the previous 6 months
- Recent recovery (within the last 12 months) or still in recovery after eating disorder diagnosis
- Medication use that could affect bone metabolism (e.g., corticosteroids, anticonvulsants, heparin, gonadotropin-releasing hormone agonists)
- Pregnancy or lactation
- Abnormal thyroid-stimulating hormone levels
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- CROSSOVER
- Arm && Interventions
Group Intervention Description Endurance and Jumping Exercises Impact Load Exercises 5 days of endurance treadmill running and 5 sets of 10 jumping exercises Endurance Exercise Only No Impact Load Exercises 5 days of endurance treadmill running
- Primary Outcome Measures
Name Time Method Change in Bone Remodeling Biomarker - C-terminal telopeptide of type 1 collagen 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6 Levels of C-terminal telopeptide of type 1 collagen will be measured from fasted blood samples drawn before and after each 5-day intervention. The enzyme-linked immunosorbent assays (ELISA) will be performed on all samples once the study is completed.
Change in Blood Metabolic Marker - Parathyroid hormone 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6 Levels of parathyroid hormone will be measured from fasted blood samples drawn before and after each 5-day intervention. These blood samples will be sent out to a local lab service at each timepoint.
Change in Blood Metabolic Marker - Insulin-like Growth Factor-1 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6 Levels of insulin-like growth factor-1 collagen will be measured from fasted blood samples drawn before and after each 5-day intervention. The ELISAs will be performed on all samples once the study is completed.
Change in Bone Remodeling Biomarker - N-terminal propeptide of type 1 procollagen 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6 Levels of N-terminal propeptide of type 1 procollagen will be measured from fasted blood samples drawn before and after each 5-day intervention. The radioimmunoassays (RIA) will be performed on all samples once the study is completed.
Change in 24-hour Glucose Patterns Continuous collection for 5 consecutive days during each intervention Blood glucose levels will be measured every 15 minutes during each 5-day intervention period using a continuous glucose monitor sensor secured to the arm. The results will provide a descriptive profile of daily glucose patterns while participants are in an energy-restricted state and exercising, either only running on a treadmill daily or running on a treadmill and completing 5 sets of 10 jumping exercises daily.
- Secondary Outcome Measures
Name Time Method Change in Body Weight 1-minute measurement in laboratory Body weight will be measured on a digital scale to the closest 0.1 kg. Body weight will be measured the day before, each of the 5 days during, and the day after each intervention.
Change in Running Economy 12-minute measurement in laboratory Running economy will be measured by collecting and analyzing inspired and expired air continuously during 3 4-minute progressive stages while running on a treadmill. The last two minutes of oxygen consumption and carbon dioxide production data will be used to determine metabolic economy (ml oxygen consumed per kg body weight per minute relative to the set work performed). Running economy will be evaluated in the laboratory at baseline and on the 5th day of each intervention period, three tests total.
Trial Locations
- Locations (1)
Virginia Polytechnic Institute and State University
🇺🇸Blacksburg, Virginia, United States