Influence of Low Energy Availability on Skeletal Muscle and Cardiovascular Health (LEA)

Influence of Low Energy Availability on Performance and Health in Trained and Recreationally Active Women

The project is designed as a randomized controlled intervention trial in which 60 young trained (n = 30) (Population A) and recreationally active (n = 30) women (Population B) with regular menstruation are divided into four groups. Population A will receive a low-calorie diet + exercise or an energy balanced diet + exercise over 10 days. Population B will receive a low-calorie diet without exercise, or an energy balanced diet over 10 days. The participants are matched in pairs based on training history and randomized. Before the diet period, the groups will undergo a 6-day control period, during which all participants must take an energy-balanced diet (± training). After the 10 days of the diet intervention period, the groups will receive an energy-balanced diet for 2 days. Before, during, and after the trial period, participants will perform performance tests. In addition, 3 muscle biopsies, 2 adipose biopsies, blood samples, urine samples will be taken during the period, as well as resting metabolic rate, electrocardiogram, flow-mediated vasodilation, and body composition over the trial period. Muscle protein synthesis rate will be measured over the period using stable isotope technique, which includes ingestion of heavy water (D2O) and collection of saliva samples daily (days 0 to 16). The primary measurement parameter is changes in muscle protein synthesis rate.

Study Overview

• Status: Recruiting
• Conditions: Diet; Deficiency; Exercise Intervention
• Intervention / Treatment: Other: Diet intervention - Energy balance; Other: Diet intervention - caloric restriction; Other: Exercise intervention

• Study Type: Interventional
• Enrollment (Anticipated): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Aarhus, Denmark, 8000
    • Recruiting
    • Aarhus University, Department for Public Health, Section for Sport Science

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• age 18-30
• BMI 18.5-30
• Regular training at least 4 times a week and a maximum of 10 times a week (≥1 times strength training, ≥1 times endurance training / interval training or interval-based sports

Exclusion Criteria:

• • Irregular menstruation within the last 6 months (shorter end 24 days or longer end 35 days cycle)

  • Used hormonal contraception within the last 3 months for the trial.
  • Injuries / pain in the lower body, which prevents participation in intense strength training
  • Medication consumption that may affect protein metabolism and inflammatory parameters.
  • Diabetes
  • Smoking
  • Unstable weight / major weight loss (weight fluctuations of more than 5 kg in the last six months)
  • Do not eat animal products
  • Eating disorder
  • Pregnancy
  • Blood donor within the last month
  • Cannot read or understand Danish

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: TRIPLE

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Energy balance	Other: Diet intervention - Energy balance; Energy balance is set to 50 kcal / kg fat-free mass
EXPERIMENTAL: Energy restriction	Other: Diet intervention - caloric restriction; Energy restriction is set to 25 kcal / kg fat-free mass
ACTIVE_COMPARATOR: Energy balance + exercise	Other: Diet intervention - Energy balance; Energy balance is set to 50 kcal / kg fat-free mass; Other: Exercise intervention; Exercise will consist of supervised resistance training, interval training and moderate intensity cycling
EXPERIMENTAL: Energy restriction + exercise	Other: Diet intervention - caloric restriction; Energy restriction is set to 25 kcal / kg fat-free mass; Other: Exercise intervention; Exercise will consist of supervised resistance training, interval training and moderate intensity cycling

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Changes in muscle protein synthesis	10 days of diet+exercise intervention

Secondary Outcome Measures

Outcome Measure	Time Frame
Markers of muscle protein synthesis and breakdown	before and after 10 days of diet+exercise intervention
Muscle glycogen and lipid levels	before and after 10 days of diet+exercise intervention
Sarcoplasmic reticulum function	before and after 10 days of diet+exercise intervention
Macrophage content in adipose tissue	before and after 10 days of diet+exercise intervention
Adipocyte area and cell size in adipose tissue	before and after 10 days of diet+exercise intervention
Expression of fat oxidative proteins in adipose tissue	before and after 10 days of diet+exercise intervention
Maximal isometric and dynamic muscle strength	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Maximal vertical jump height	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Repeated sprint ability	before and after 10 days of diet+exercise intervention and 2 days of energybalance
4-minute time trial performance	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Sex hormone levels	During the course of the whole intervention period (18 days)
Cortisol Levels	During the course of the whole intervention period (18 days)
Inflammatory levels	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Bone turnover levels	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Electrocardiogram - Qt interval	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Flow mediated vasodilation	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Resting metabolic rate	before and after 10 days of diet+exercise intervention and 2 days of energybalance
Body composition	before and after 10 days of diet+exercise intervention and 2 days of energybalance

Collaborators and Investigators

• Sponsor: University of Aarhus
• Collaborators: University of Copenhagen; University of Southern Denmark

Study record dates

Study Major Dates

• Study Start (ACTUAL): March 1, 2021
• Primary Completion (ACTUAL): July 1, 2022
• Study Completion (ANTICIPATED): December 1, 2024

Study Registration Dates

• First Submitted: March 24, 2021
• First Submitted That Met QC Criteria: March 26, 2021
• First Posted (ACTUAL): March 29, 2021

Study Record Updates

• Last Update Posted (ACTUAL): November 17, 2022
• Last Update Submitted That Met QC Criteria: November 16, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nutrition Disorders; Malnutrition
• Other Study ID Numbers: LEA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No