Relative Energy Deficiency in Sport
Conditions
Keywords
Bone metabolism, Endurance exercise, Low energy availability, Jump training
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.
Interventions
BEHAVIORALImpact Load Exercises
Participants will complete 50-65 min running protocol on treadmill and 5 sets of 10 jumping exercises for 5 consecutive days. Participants will also be provided all meals and snacks to induce a energy-restricted state for the 5-day period.
BEHAVIORALNo Impact Load Exercises
Participants will complete only a 50-65 min running protocol on treadmill for 5 consecutive days. Participants will also be provided all meals and snacks to induce a energy-restricted state for the 5-day period.
Sponsors
Virginia Polytechnic Institute and State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
NONE
Intervention model description
Randomized crossover study design
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
Countries
United States
Participant flow
Recruitment details
38 individuals were screened for eligibility between August 2, 2022 and October 13, 2023 in Southwest Virginia.
Pre-assignment details
14 of 38 participants were randomized. Of those not randomized, 17 did not meet inclusion criteria and 7 declined to participate.
Participants by arm
| Arm | Count |
|---|---|
| RUN, Then RUN+J Participants first completed a 5-day period of energy restriction while running on the treadmill every day (RUN). After a washout period of at least one menstrual cycle, they then completed another 5-day period of energy restriction while running on the treadmill daily in addition to completing 5 sets of 10 jumping exercises each day (RUN+J). | 6 |
| RUN+J, Then RUN Participants first completed a 5-day period of energy restriction while running on the treadmill and completing 5 sets of 10 jumping exercises each day (RUN+J). After a washout period of at least one menstrual cycle, they then completed another 5-day period of energy restriction while only running on the treadmill each day (RUN). | 7 |
| Total | 13 |
Baseline characteristics
| Characteristic | RUN+J, Then RUN | Total | RUN, Then RUN+J |
|---|---|---|---|
| Age, Continuous | 26.9 Years STANDARD_DEVIATION 3.6 | 26.2 Years STANDARD_DEVIATION 3.8 | 25.3 Years STANDARD_DEVIATION 4.2 |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 1 Participants | 2 Participants | 1 Participants |
| Race (NIH/OMB) More than one race | 1 Participants | 1 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 5 Participants | 10 Participants | 5 Participants |
| Sex: Female, Male Female | 7 Participants | 13 Participants | 6 Participants |
| Sex: Female, Male Male | 0 Participants | 0 Participants | 0 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 12 | 0 / 10 |
| other Total, other adverse events | 0 / 12 | 0 / 10 |
| serious Total, serious adverse events | 0 / 12 | 0 / 10 |
Outcome results
Primary
Change in Blood Metabolic Marker - Insulin-like Growth Factor-1
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.
Time frame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
Population: Only participants who completed the entire intervention period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Endurance and Jumping Exercises (RUN+J) | Change in Blood Metabolic Marker - Insulin-like Growth Factor-1 | -11.4 ng/mL | Standard Deviation 10.3 |
| Endurance Exercise Only (RUN) | Change in Blood Metabolic Marker - Insulin-like Growth Factor-1 | -8.0 ng/mL | Standard Deviation 6.3 |
Comparison: Null hypothesis is that there was no difference in change of IGF1 between RUN and RUN+J.p-value: 0.308Mixed Models Analysis
Primary
Change in Blood Metabolic Marker - Parathyroid Hormone
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.
Time frame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
Population: Only participants who completed the entire intervention period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Endurance and Jumping Exercises (RUN+J) | Change in Blood Metabolic Marker - Parathyroid Hormone | 3.3 pg/mL | Standard Deviation 6.1 |
| Endurance Exercise Only (RUN) | Change in Blood Metabolic Marker - Parathyroid Hormone | -1.0 pg/mL | Standard Deviation 11.8 |
p-value: 0.309Mixed Models Analysis
Primary
Change in Bone Remodeling Biomarker - C-terminal Telopeptide of Type 1 Collagen (CTX)
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.
Time frame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
Population: Only participants who completed the entire intervention period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Endurance and Jumping Exercises (RUN+J) | Change in Bone Remodeling Biomarker - C-terminal Telopeptide of Type 1 Collagen (CTX) | 0.04 ng/mL | Standard Deviation 0.09 |
| Endurance Exercise Only (RUN) | Change in Bone Remodeling Biomarker - C-terminal Telopeptide of Type 1 Collagen (CTX) | 0.04 ng/mL | Standard Deviation 0.12 |
Comparison: Null hypothesis is that there was no difference in change of CTX between RUN and RUN+J.p-value: 0.714Mixed Models Analysis
Primary
Change in Bone Remodeling Biomarker - N-terminal Propeptide of Type 1 Procollagen
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.
Time frame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
Population: Only participants who completed the entire intervention period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Endurance and Jumping Exercises (RUN+J) | Change in Bone Remodeling Biomarker - N-terminal Propeptide of Type 1 Procollagen | -3.1 ng/mL | Standard Deviation 5.7 |
| Endurance Exercise Only (RUN) | Change in Bone Remodeling Biomarker - N-terminal Propeptide of Type 1 Procollagen | 1.1 ng/mL | Standard Deviation 7.2 |
Comparison: Null hypothesis is that there was no difference in change of PINP between RUN and RUN+J.p-value: 0.246Mixed Models Analysis
Secondary
Change in Ferritin
Fasted serum ferritin was measured before and after each 5-day intervention period.
Time frame: 10-minute blood draw in laboratory; samples assessed on intervention day 0 and day 6
Population: Only participants who completed the entire intervention period were included in the analysis.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Endurance and Jumping Exercises (RUN+J) | Change in Ferritin | 4.1 ng/mL | Standard Deviation 11.3 |
| Endurance Exercise Only (RUN) | Change in Ferritin | 11.4 ng/mL | Standard Deviation 11.5 |
Comparison: Null hypothesis is that there was no difference in change of ferritin between RUN and RUN+J.p-value: 0.207Mixed Models Analysis