Influence of Low Energy Availability on Skeletal Muscle and Cardiovascular Health

University of Aarhus30 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Enrollment

Conditions

Diet; Deficiency

Eligibility

Sex: FEMALEMin age: 18 YearsMax age: 30 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Changes in muscle protein synthesis

Time frame: 10 days of diet+exercise intervention

Secondary Outcomes

Markers of muscle protein synthesis and breakdown

Time frame: before and after 10 days of diet+exercise intervention

Muscle glycogen and lipid levels

Time frame: before and after 10 days of diet+exercise intervention

Sarcoplasmic reticulum function

Time frame: before and after 10 days of diet+exercise intervention

Macrophage content in adipose tissue

Time frame: before and after 10 days of diet+exercise intervention

Adipocyte area and cell size in adipose tissue

Time frame: before and after 10 days of diet+exercise intervention

Expression of fat oxidative proteins in adipose tissue

Time frame: before and after 10 days of diet+exercise intervention

Maximal isometric and dynamic muscle strength