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The Effects of Lifting Light or Heavy Weights on Muscle Growth and Strength in Trained Young Men

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ClinicalTrials.gov Identifier: NCT02139865
Recruitment Status : Completed
First Posted : May 15, 2014
Last Update Posted : March 19, 2018
Information provided by (Responsible Party):
McMaster University

Brief Summary:

When practicing weightlifting regularly the body makes new proteins within the muscle.

These new proteins can increase the size of the cells within the muscle to make them larger, a process called hypertrophy. The common convention surrounding gains in skeletal muscle size and strength is that heavy weights are needed. In contrast, lifting lighter weights are thought to be required to induce muscular endurance and not to promote growth. However, it has previously been shown in untrained men that lifting lighter weights results in similar gains in muscle mass and strength as lifting heavier weights. The purpose of this study is to examine how performing resistance training of different intensities (light or heavy weights) affects the degree of muscle growth and strength gain in individuals who are already resistance training.

This information will be valuable when designing exercise protocols for increasing muscle size and strength at all ages, or in individuals returning from injury, as a way to stimulate muscle growth and promote strength gains without the need to lift heavy weights.

Condition or disease Intervention/treatment Phase
Skeletal Muscle Hypertrophy Muscle Weakness Behavioral: 30% 1RM Behavioral: 80% 1RM Not Applicable

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 50 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Other
Official Title: The Effects of Resistance Training Intensity on Muscular Hypertrophy and Strength in Young, Resistance Trained Men
Study Start Date : May 2014
Actual Primary Completion Date : December 2015
Actual Study Completion Date : March 2016

Arm Intervention/treatment
Experimental: 30%
Training at 30% 1RM
Behavioral: 30% 1RM
Participant exercises using a protocol tailored at 30% of their 1RM

Experimental: 80%
Training at 80% 1RM
Behavioral: 80% 1RM
Participant exercises using a protocol tailored at 80% of their 1RM

Primary Outcome Measures :
  1. Muscle Volume [ Time Frame: 0 weeks (baseline) and 12 weeks ]
    Change from baseline at 12 weeks Measured via 4 compartment model

Secondary Outcome Measures :
  1. Gene expression [ Time Frame: 0 weeks (baseline) and 12 weeks ]
    Change from baseline at 12 weeks . Gene expression for proteins involved in muscle protein synthesis measured from muscle biopsy.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 30 Years   (Adult)
Sexes Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Male
  • Aged 18-30 years old
  • Non-obese (Body mass index less than 30 kg/m2)
  • Non-smoker
  • Healthy based on questionnaire responses (see exclusion criteria)
  • Resistance trained (Resistance training > 2 times per week for 2 years, minimum 1 lower body exercise session per week)

Exclusion Criteria:

  • Allergies to milk proteins (whey or casein)
  • Any acute or chronic illness, cardiac, pulmonary, liver, or kidney abnormalities, uncontrolled hypertension, insulin- or non-insulin dependent diabetes or other metabolic disorders-all ascertained through medical history screening questionnaires
  • Arthritic conditions
  • Individuals who consume any analgesic or anti-inflammatory drug(s), prescription or non- prescription, chronically will be excluded
  • A history of neuromuscular problems
  • Individuals on any medications known to affect protein metabolism (i.e. corticosteroids, non-steroidal anti-inflammatories, or prescription strength acne medications).

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02139865

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Canada, Ontario
Exercise Metabolism Research Laboratory, McMaster Univeristy
Hamilton, Ontario, Canada, L8S 4K1
McMaster University
Hamilton, Ontario, Canada, L8S 4L8
Sponsors and Collaborators
McMaster University
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Principal Investigator: Stuart Phillips, Ph.D. McMaster University
Publications of Results:
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Responsible Party: McMaster University
ClinicalTrials.gov Identifier: NCT02139865    
Other Study ID Numbers: REB 14-333
First Posted: May 15, 2014    Key Record Dates
Last Update Posted: March 19, 2018
Last Verified: March 2016
Additional relevant MeSH terms:
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Muscle Weakness
Pathological Conditions, Anatomical
Muscular Diseases
Musculoskeletal Diseases
Neuromuscular Manifestations
Neurologic Manifestations
Nervous System Diseases
Pathologic Processes