Clinical trial NCT05341700: Impact Loading Effect on Bone Biomarkers in Female Runners
Official title: The Effect of Impact Loading on Bone Biomarkers in Energy-Restricted Female Runners
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Relative Energy Deficiency in Sport
Keywords: Bone metabolism
Endurance exercise
Low energy availability
Jump training
Lead sponsor: Virginia Polytechnic Institute and State University
Sponsor class: OTHER
First posted: 2022-04-22
Enrollment: 16
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Randomized crossover study design
Primary purpose: PREVENTION

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.

Eligibility criteria: Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Primary outcomes:
measure: Change in Bone Remodeling Biomarker - N-terminal propeptide of type 1 procollagen
timeFrame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
measure: Change in Bone Remodeling Biomarker - C-terminal telopeptide of type 1 collagen
timeFrame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
measure: Change in Blood Metabolic Marker - Parathyroid hormone
timeFrame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
measure: Change in Blood Metabolic Marker - Insulin-like Growth Factor-1
timeFrame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
measure: Change in 24-hour Glucose Patterns
timeFrame: Continuous collection for 5 consecutive days during each intervention
Secondary outcomes:
measure: Change in Running Economy
timeFrame: 12-minute measurement in laboratory
measure: Change in Body Weight
timeFrame: 1-minute measurement in laboratory
Other outcomes:
Locations:
city: Blacksburg
country: United States
facility: Virginia Polytechnic Institute and State University
state: Virginia
Study officials:
affiliation: Virginia Polytechnic Institute and State University (Virginia Tech)
name: Enette Larson-Meyer, PhD
role: PRINCIPAL_INVESTIGATOR
References: