The Effect of Peak Force At Long and Short Muscle Lengths and the Impact on Muscle Growth and Strength

NCT06666127 | Enrolling By Invitation

• 1 other identifier: H24-01989
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to learn the effect of applying peak force/resistance to skeletal muscles during resistance exercise training in young and healthy adults. Participants will undergo two types of resistance training conditions that are randomly assigned to the left arm and leg and the right arm and leg. The LONG condition refers to Prime Fitness machines set to setting number '3' which applies peak force at a long muscle length. The SHORT condition refers to Prime Fitness machines set to setting number '2' which applies peak force at a short muscle length. The main questions the trial aims to answer are:

• Resistance train the left and right arm and leg with two separate conditions; LONG and SHORT for 12 weeks, with the first and last weeks dedicated to only strength testing (Isotonic and Isokinetic) and measuring muscle volume via magnetic resonance imaging (MRI)
• Visit the gym for resistance training 2 times per week
• Visit the UBC MRI Research Facility in weeks 1 and 12 for MRI of muscle volume

Conditions

Muscle Hypertrophy; Muscular Strength

Keywords

Muscle Hypertrophy; Muscular Strength; Long Muscle Lengths; Peak Force; Length-Tension Relationship; Range of Motion; Neuromechanical Matching; Resistance Training; Muscle Oxygenation

Outcome Measures

Primary Outcomes (1)

• Muscle Volume

  Muscle volume of the pectoralis major, deltoid and gluteus maximus muscle will be measured by cross sectional area (CSA) via Magnetic Resonance Imaging (MRI). The entire muscle length will be imaged and images at 25%, 50% and 75% of the entire muscle length will be analyzed to calculate CSA and any regional differences in hypertrophy.

  From enrolment to the end of the intervention at 12 weeks

Secondary Outcomes (3)

• Isotonic Strength testing

  Initial testing in week 1 and final testing in week 12

• Isokinetic Strength Testing

  Initial testing in week 1 and final testing in week 12

• Muscle Oxygenation

  Week 2 and week 11.

Other Outcomes (1)

• Visual Analog Scale of Perceived Rating of Muscular Discomfort

  From week 2 to week 4 and week 11 only.

Study Arms (1)

SHORT and LONG Training Protocol

EXPERIMENTAL

Using a within subject design, participants will have the arms and legs from both left and right side of the body (divided by sagittal plane) randomly assigned to either LONG or SHORT conditions. Participants will then engage in maximal strength testing on Prime Fitness machines (1RM) as well as isokinetic strength testing (Biodex) in weeks 1 and 12. Participants will engage in the LONG and SHORT training sessions for 10 weeks in duration from week 2 until week 11.

Other: LONG and SHORT Resistance Training; Other: Maximal Isotonic Strength Testing (1RM); Other: Isokinetic Strength Testing; Other: Muscle Oxygenation

Interventions

LONG and SHORT Resistance Training OTHER

One side of the body will be randomly assigned to perform exercises in position 3 (LONG) with the other randomly assigned to position 2 (SHORT) of Prime Fitness horizontal shoulder adduction, horizontal shoulder abduction, shoulder abduction and hip extension. Each exercise will include 1 warm up set at 50% 1RM followed by 4-5 sets of 8-12 repetitions per limb. 2 minutes of rest between sets on the same side of body will be administered as the participant will alternate between the right and left limb. The left and right side limbs will alternate each session in which one starts each exercise, resulting in 10 training sessions each where the left and right limbs starts first on each exercise. All sets will be performed to momentary failure. A Dynamic Double Progression will be employed to ensure intensity is maintained.

SHORT and LONG Training Protocol

Maximal Isotonic Strength Testing (1RM) OTHER

Each limb will perform a 1RM strength test with each Prime Fitness machine training horizontal shoulder adduction, horizontal shoulder abduction, shoulder abduction and hip extension respectively. Each machine will be set to position 1 (maximal load in mid-range). Testing will occur in weeks 1 and 12 of the study with the non-dominant arm and leg tested before the dominant arm and leg in each exercise. Participants self-selects first warm up set with a weight that is performed between 6-10 repetitions on both limbs. Rest for 1 minute between limbs and subsequent set. A weight is then selected by research staff to perform 3 repetitions with based on previous set. Load is now increased until 1RM is achieved. Rest periods should remain at least 1 minute alternating between limbs, with 1RM being complete within 3-5 attempts. Participant will rest 2-5 minutes before starting testing on the next exercise. Repeat for all exercises. Use pre testing data to inform 1RM attempts for post testing.

SHORT and LONG Training Protocol

Isokinetic Strength Testing OTHER

Participants will engage in isokinetic strength testing on the isokinetic dynamometer (Biodex) in weeks 1 and 12 for each of the four movements: Horizontal shoulder adduction, horizontal shoulder abduction, shoulder abduction and hip extension. Participants will perform each movement unilaterally. Participants will start with the non-dominant arm and leg for each movement. Each movement will be tested through A maximal active range of motion. Participants will complete 10 sub-maximal repetitions to allow familiarization each movement. After a 2-minute rest, participants will complete 3 maximal concentric and eccentric repetitions with 30 seconds rest at 30 degrees per second before the Biodex is reset for the next movement.

SHORT and LONG Training Protocol

Muscle Oxygenation OTHER

During the first and last LONG and SHORT training session (visit 5 and visit 24), A near infrared spectroscopy sensor (NIRS device) (Trainred) will be affixed to the muscle belly of the deltoid during the lateral raise exercise to measure muscle oxygenation.

SHORT and LONG Training Protocol

Eligibility Criteria

• Age: 19 Years - 30 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Any sex
• Able to understand and communicate in English
• years of age
• All "No" answers on the CSEP Get Active questionnaire or doctors' approval to participate
• Untrained participants: no structured resistance training over the past 12-months (i.e. \> 2 hours per week of structured/periodized training)

You may not qualify if:

• BMI lower than 18 or greater than 30
• Difficulty to understand and communicate in English
• Current use of cigarettes or other nicotine devices
• Any major uncontrolled cardiovascular, muscular, metabolic, and/or neurological disorders
• Any medical condition impacting the ability to participate in maximal exercise
• Type one or type two diabetes
• Diagnosis of cancer or undergoing cancer treatment in the past 12 months
• Drug therapy with any drugs that alter skeletal muscle metabolism (i.e., Metformin, Benzodiazepines)
• Omega-3 (EPA, DHA, fish oil) supplementation within the previous 6 weeks
• Implants containing ferrous metal
• Surgery or tattoos (including tattooed eyeliner) in the last 6 weeks
• Pregnancy

Sponsors & Collaborators

• University of British Columbia: lead

Study Sites (1)

University of British Columbia

Vancouver, British Columbia, V6T 1Z4, Canada

Location

Related Publications (1)

• Maeo S, Wu Y, Huang M, Sakurai H, Kusagawa Y, Sugiyama T, Kanehisa H, Isaka T. Triceps brachii hypertrophy is substantially greater after elbow extension training performed in the overhead versus neutral arm position. Eur J Sport Sci. 2023 Jul;23(7):1240-1250. doi: 10.1080/17461391.2022.2100279. Epub 2022 Aug 11.

  PMID: 35819335 BACKGROUND

Study Officials

• Dr. Cameron Mitchell

  University of British Columbia, School of Kinesiology

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: OTHER
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Within-Subject Design: Each participant will have the left arm and leg as well as the right arm and leg randomly assigned to the LONG or SHORT condition. Each participant will perform both conditions, exclusively for the left or right sided limbs. This helps to control for genetics, nutrition, recovery, stress management and training history as each participant acts as a self-control group as well as both experimental conditions.

Study Record Dates

• First Submitted: October 22, 2024
• First Posted: October 30, 2024
• Study Start: December 1, 2024
• Primary Completion: May 1, 2025
• Study Completion: May 30, 2025
• Last Updated: November 8, 2024

Record last verified: 2024-10

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)