Impact Loading Effect on Bone Biomarkers in Female Runners

Not Applicable

Completed

Conditions: Relative Energy Deficiency in Sport

Registration Number: NCT05341700

Lead Sponsor: Virginia Polytechnic Institute and State University

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 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: 14

Inclusion Criteria

Females runners with regular menstrual cycles, not using contraceptives
Body Mass Index between 18.5-30.0 kg/m2
Weight stable (+/- 2 kg) for 6 months
VO2max of ≥35 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

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
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	Plasma N-terminal propeptide of type 1 procollagen (PINP) was collected from fasted blood samples drawn before and after each 5-day intervention. The enzyme-linked immunosorbent assays (ELISA) were performed on all samples upon study completion.
Change in Bone Remodeling Biomarker - C-terminal Telopeptide of Type 1 Collagen (CTX)	10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6	Serum C-terminal telopeptide of type 1 collagen (CTX) was collected from fasted blood samples drawn before and after each 5-day intervention. The enzyme-linked immunosorbent assays (ELISA) were performed on all samples upon study completion.
Change in Blood Metabolic Marker - Parathyroid Hormone	10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6	Parathyroid hormone levels were measured from fasted blood samples collected before and after each 5-day intervention. The enzyme-linked immunosorbent assays (ELISA) were performed on all samples upon study completion.
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	Insulin-like growth factor-1 (IGF1) concentration was measured from fasted blood samples collected before and after each 5-day intervention. The enzyme-linked immunosorbent assays (ELISA) were performed on all samples upon study completion.

Secondary Outcome Measures

Name	Time	Method
Change in Ferritin	10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6	Fasted serum ferritin was measured before and after each 5-day intervention period.

Trial Locations

Locations (1): Virginia Polytechnic Institute and State University
🇺🇸
Blacksburg, Virginia, United States
Virginia Polytechnic Institute and State University
🇺🇸Blacksburg, Virginia, United States