Prehabilitative Exercise Prior to Immobilization (PREHAB)

Prehabilitative Exercise - Can the Physiological Consequences of Immobilization be Prevented?

This is a 10-week human study involving 24 younger (20-35 y) and 24 older (65-85 y) healthy individuals. All participants will undergo unilateral immobilization of a knee for 7-10 days, followed by 4 weeks of heavy resistance exercise training (HReT). Half of the participants (12 younger and 12 older) will also undergo 4 weeks HReT prior to the immobilization. Prehabilitative exercise may confer protective effects on subsequent immobilization, and the various underlying mechanisms involved

Study Overview

• Status: Completed
• Conditions: Sarcopenia; Disuse Atrophy; Skeletal Muscle Atrophy
• Intervention / Treatment: Other: Prehabilitative exercise

• Study Type: Interventional
• Enrollment (Actual): 64
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Denmark
  • Capital Region
    • Copenhagen, Capital Region, Denmark, 2400
      • Institute of Sports Medicine Copenhagen

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age: Between 20-35 years old or between 65-85 years old.
• BMI: Between 18.5 and 35 kg/m2.
• Healthy and well, with normal dietary habits (not vegan).

Exclusion Criteria:

• More than one muscle biopsy previously taken from both vastus lateralis muscles.
• Smoking.
• Pregnancy.
• Past or present substance or alcohol abuse.
• Medical/surgical conditions that are assessed to affect protein synthesis or the participant's involvement in the trial.
• Knee pain that could affect the completion of the training intervention.
• High intake of supplements that increase the risk of bleeding during muscle biopsy (such as fish oil and ginger).
• Participation in regular strength training within the past year.
• Regular participation in structured sports.
• Current use of blood-thinning medication.
• Previous participation in trials involving oral intake of heavy water.
• Metal in the body preventing MRI scanning.
• For the older group, not having gone through menopause, and for the younger group, not having a regular menstrual cycle.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Prehab	Other: Prehabilitative exercise; 3-4 weeks of heavy resistance exercise
No Intervention: NoTrain

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quadriceps cross-sectional area	Quadriceps cross-sectional area measured by MRI	From pre (week 0) to post immobilization (week 5)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle fiber size	Muscle fiber size assessed by histochemical stainings	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Denervated muscle fibers	Assessment denervated fibers using histochemical stainings	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Muscle protein synthesis	Muscle protein synthesis assessed using deuterium (heavy water)	From pre immobilization (week 4) to post immobilization (week 5)
Muscle gene expression	Muscle gene expression assessed by RNA sequencing	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Brain structure	Brain structure measured by MRI	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Brain function	Brain function measured by MRI	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Tendon structure	Tendon structure measured by MRI	From pre (week 0) to post immobilization (week 5)
Tendon ultrastructure	Tendon tissue analysed by molecular analyses	From pre immobilization (week 4) to post immobilization (week 5)
Lean-body mass	Whole-body and thigh lean-body mass assessed using DEXA-scans	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Muscle strength	Muscle strength during knee extension assessed using isokinetic and isometric dynamometers	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Balance	One-legged balanced assessed using a force platform	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)
Force variability	Force variability during knee extension assessed using submaximal isometric contractions	From pre (week 0) to post immobilization (week 5) and post retraining (week 10)

Collaborators and Investigators

• Sponsor: Bispebjerg Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 6, 2024
• Primary Completion (Actual): June 1, 2025
• Study Completion (Actual): June 1, 2025

Study Registration Dates

• First Submitted: December 19, 2023
• First Submitted That Met QC Criteria: January 3, 2024
• First Posted (Actual): January 16, 2024

Study Record Updates

• Last Update Posted (Estimated): September 19, 2025
• Last Update Submitted That Met QC Criteria: September 15, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Musculoskeletal Diseases; Nervous System Diseases; Muscular Diseases; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Neuromuscular Diseases; Atrophy; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Sarcopenia; Muscular Atrophy; Muscular Disorders, Atrophic
• Other Study ID Numbers: BBH164

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
• product manufactured in and exported from the U.S.: No