Muscle Adaptations in Children and Adults Following Twelve Weeks of Flywheel or Weight Stack Resistance Exercise

Summary

The goal of this trial is to compare resistance exercise using traditional techniques and flywheel training to controls in healthy children ages nine to 13 and adults ages 18 to 50. The main questions it aims to answer are:

* The degree of response to resistance exercise in children compared to adults regarding muscle hypertrophy and strength?
* Is there a negative impact on the physis of children due to resistance exercise?

Participants will be randomized to one of three groups, control, traditional resistance exercise, or flywheel. Following a baseline battery of tests, they will enter a 12-week training period, using leg press and leg extension. Additionally, post-training tests are conducted, and an eight-week detraining period commences followed by new tests. Researchers will compare children and adults and each intervention arm to see if children can achieve muscle hypertrophy, the degree and rate of changes in strength, and the potential impact on the physis.

Conditions

• Resistance Exercise
• Muscle Hypertrophy
• Skeletal Muscle
• EMG
• Magnetic Resonance Imaging
• Growth Plate Early Closing
• Children, Adult

Interventions

OTHER

Flywheel Resistance Exercise

FW is conducted in a leg extension machine (LegExx, Exxentric, Stockholm, Sweden) and leg press machine (YoYo™ Leg Press, nHANCE, Sweden).

OTHER

Weight Stack Resistance Exercise

WS is conducted in a leg extension machine (Seated leg press, Nordic Gym, Bollnäs, Sweden) and a leg press machine (Seated leg extension, Nordic Gym, Bollnäs, Sweden)

Sponsors & Collaborators

• Karolinska Institutet

  collaborator OTHER

• Umeå University

  collaborator OTHER

• Medical Research Council of Southeast Sweden

  collaborator OTHER_GOV

• Swedish Research Council for Sport Science

  collaborator OTHER

• Linkoeping University

  collaborator OTHER_GOV

• The Swedish Research Council

  collaborator OTHER_GOV

• Björn Alkner

  lead OTHER_GOV

Principal Investigators

• Björn A Alkner, MD, PhD · Department of Orthopaedic Surgery, Eksjö, Region Jönköping County and Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

9 Years

Max Age

50 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-08-28

Primary Completion

2025-02-02

Completion

2025-02-12

Countries

• Sweden

Study Locations