Lower and Higher Load Resistance Exercise Protocols: Acute Muscle Activation and Skeletal Muscle Hypertrophy

NCT03991117 | Completed

• 1 other identifier: HIREB 0802
• Study Type: interventional
• Target: 10
• Locations: 0 countries
• Sites: N/A

Brief Summary

How much weight an individual lifts per workout does not dictate the relative increase in muscle size the individual gains following weeks of training, which is contrary to current strength training dogma. Specifically, researchers have concluded that so long as an individual performs resistance exercise with maximum effort, it is not necessary to lift with relatively heavy loads. However, other laboratories, on the basis of surface electromyography measurements, have challenged the thesis that lighter loads can result in the hypertrophy of larger, type II muscle fibres. Therefore, the purpose of this study was to combine surface electromyography measurements with direct measurements of muscle fibre activation to see if muscle fibre activation was truly dependent on load. The investigators hypothesized that all muscle fibres would be activated when the resistance exercise was performed with maximal effort.

Conditions

Muscle Hypertrophy; Muscle Fibre Activation

Keywords

muscle fibre activation; electromyography

Outcome Measures

Primary Outcomes (2)

• Concentration of glycogen in muscle fibres

  Histochemical assessment of muscle glycogen via muscle biopsies

  three weeks

• Amplitude of electrical activity above the quadriceps muscles

  Surface electromyography assessment via electrodes during the unilateral resistance exercise

  three weeks

Study Arms (4)

80 %1RM, Regular Tempo

EXPERIMENTAL

Participants performed three sets of unilateral knee extension with a load that was 80 % of their one-repetition maximum (1RM) at a tempo of three seconds per repetition.

Behavioral: resistance exercise

80 %1RM, Slow Tempo

EXPERIMENTAL

Participants performed three sets of unilateral knee extension with a load that was 80 % of their one-repetition maximum (1RM) at a tempo of seven seconds per repetition.

Behavioral: resistance exercise

30 %1RM, Regular Tempo

EXPERIMENTAL

Participants performed three sets of unilateral knee extension with a load that was 30 % of their one-repetition maximum (1RM) at a tempo of three seconds per repetition.

Behavioral: resistance exercise

30 %1RM, Slow Tempo

EXPERIMENTAL

Participants performed three sets of unilateral knee extension with a load that was 30 % of their one-repetition maximum (1RM) at a tempo of seven seconds per repetition.

Behavioral: resistance exercise

Interventions

resistance exercise BEHAVIORAL

unilateral knee extensions until fatigue with varying load and speeds of contraction

30 %1RM, Regular Tempo; 30 %1RM, Slow Tempo; 80 %1RM, Regular Tempo; 80 %1RM, Slow Tempo

Eligibility Criteria

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

You may qualify if:

• healthy
• male
• years of age

You may not qualify if:

• Have any acute or chronic illness such as cardiac, pulmonary, liver, or kidney abnormalities, uncontrolled hypertension, insulin- or non-insulin dependent diabetes or other metabolic disorders-all ascertained through a medical history screening questionnaire
• Experience arthritic conditions
• Smoke tobacco products
• Consume any analgesic or anti-inflammatory drug(s), prescription or non-prescription, chronically
• Have a history of neuromuscular complications
• Are on any medications known to affect protein metabolism (i.e. corticosteroids, non-steroidal anti-inflammatories, or prescription strength acne medications).
• Have an extensive history of RE training in the year prior to study entry.

Sponsors & Collaborators

• McMaster University: lead

MeSH Terms

Interventions

Resistance Training

Intervention Hierarchy (Ancestors)

Exercise Therapy; Rehabilitation; Aftercare; Continuity of Patient Care; Patient Care; Therapeutics; Physical Therapy Modalities; Physical Conditioning, Human; Exercise; Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Study Officials

• Stuart Phillips, PhD

  McMaster University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The study investigators that performed the histochemical analysis were masked to which participant and which condition they were assessing at the time of analysis.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Tier 1 Canada Research Chair and Professor

Model Details: Each individual performed four bouts of resistance exercise that varied in load and speed of contraction on two separate days (one condition each leg per visit).

Study Record Dates

• First Submitted: June 17, 2019
• First Posted: June 19, 2019
• Study Start: January 4, 2016
• Primary Completion: March 1, 2016
• Study Completion: March 1, 2016
• Last Updated: June 19, 2019

Record last verified: 2019-06

Data Sharing

• IPD Sharing: Will not share