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

Официальное название

Determining the Effect of Muscle Length At Peak Force on Resistance Training Induced Hypertrophy

Обзор

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: 1. Does applying peak force at a longer or shorter muscle length during resistance exercise training result in greater muscle growth? 2. Does applying peak force at a longer or shorter muscle length during resistance exercise training result in greater muscle growth? We hypothesize that: 1. LONG will induce greater hypertrophy compared to SHORT conditions 2. LONG will result in greater increases in 1RM strength compared to SHORT 3. LONG and SHORT training will result in angle specific increases in isokinetic strength 4. Muscle oxygenation will decline to a greater degree during LONG compared to SHORT exercise and this will be maintained between weeks 1 and 12 of training The investigators will compare the change in muscle volume and muscular strength between the LONG and SHORT training conditions, which each participant will have the left arm and leg as well as the right arm and leg randomly assigned to either exclusively LONG or SHORT conditions. Participants will: * 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

Подробное описание

Statistical Analysis:

Null Hypothesis Significance Testing (NHST) will be used to measure differences in hypertrophy, differences in 1RM strength, Isokinetic strength and muscle oxygenation between LONG and SHORT conditions.

It is anticipated that this study will require at least 20 participants to be screened and registered into the trial. Data will be analyzed on the basis that all participants will be included in the analysis. Participants who drop out (withdraw from treatment) will be followed up with to collect all available data and will not be replaced. Missing data will be assumed missing at random.

Sample Size Calculation:

Based on the effect size reported by Maeo et al. (2023) for difference in triceps brachia long head hypertrophy between training performed in the lengthened compared to shortened position using a within participant design, (d=0.61) a sample size of 20 participants was calculated to achieve an a priori power of 90%.

Вмешательства

• Другое LONG and SHORT Resistance Training
  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 lef
• Другое Maximal Isotonic Strength Testing (1RM)
  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 repet
• Другое Isokinetic Strength Testing
  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
• Другое Muscle Oxygenation
  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.

Первичные конечные точки

• Muscle Volume [Срок оценки: From enrolment to the end of the intervention at 12 weeks]

Вторичные конечные точки (3)

• Isotonic Strength testing [Срок оценки: Initial testing in week 1 and final testing in week 12]
• Isokinetic Strength Testing [Срок оценки: Initial testing in week 1 and final testing in week 12]
• Muscle Oxygenation [Срок оценки: Week 2 and week 11.]

Критерии участия

Критерии включения

• Any sex
• Able to understand and communicate in English
• 19-30 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)

Критерии исключения

• 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

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Да

Дизайн исследования

Распределение

Не применимо

Модель

Одна группа

Маскирование

Открытое

Основная цель

Другое

Центры проведения

Канада · 1 центр

• University of British Columbia — Vancouver

Публикации

• 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

Идентификаторы

NCT: NCT06666127 · H24-01989

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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