Eccentric Resistance Exercise for Skeletal Muscle Response

Overseen By Stephen M Cornish, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: University of Manitoba

Disqualifiers: Health conditions affecting exercise

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 3

12 Participants Needed

Trial Summary

What is the purpose of this trial?

The purpose of this study is to evaluate the acute local skeletal muscle inflammatory response to thigh muscle (quadriceps) eccentric muscle actions. Eccentric muscle actions occur when the muscle is lengthening as it contracts. This is a pilot project to assess the degree of inflammatory biomarkers, called myokines, that are released locally in skeletal muscle tissue after an acute bout of resistance-exercise using a resistance-exercise machine called an isokinetic dynamometer.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the treatment Eccentric Resistance Exercise for Skeletal Muscle Response?

Research shows that eccentric resistance exercise can increase muscle strength and function, as seen in studies with stroke patients and other training programs. This type of exercise has been found to improve both eccentric and concentric muscle strength, which can help with daily activities and rehabilitation. ^{1 2 3 4 5}

Is eccentric resistance exercise generally safe for humans?

Eccentric resistance exercise is generally safe, but it can cause muscle soreness and muscle damage, especially if not done properly. Some studies suggest that using isokinetic dynamometers may result in less muscle soreness compared to other exercise types. ^{1 5 6 7 8}

How is eccentric resistance exercise different from other treatments for muscle response?

Eccentric resistance exercise, performed using an isokinetic dynamometer, is unique because it focuses on lengthening the muscle under tension, which can lead to greater strength improvements compared to traditional concentric exercises (where the muscle shortens). This type of exercise may also result in less muscle soreness compared to other exercise modalities, making it potentially beneficial for rehabilitation and injury prevention. ^{5 8 9 10 11}

Research Team

Stephen M Cornish, PhD

Principal Investigator

University of Manitoba

Eligibility Criteria

This trial is for individuals who are interested in participating in a study to understand how their thigh muscles respond after doing specific resistance exercises that involve muscle lengthening during contraction. The details about who can join or reasons why someone might not be able to participate are not provided.

Inclusion Criteria

Healthy

Recreationally active (≥ 150 minutes of moderate to vigorous physical activity per week for at least the past three months)

Exclusion Criteria

Answered 'yes' to the Get Active Questionnaire which screens for health conditions that may affect exercise ability

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1 week

Pre-Exercise Rest

Participants rest for 30 minutes before exercise and provide a baseline muscle biopsy

30 minutes

1 visit (in-person)

Exercise

Participants perform 300 repetitions of maximal isokinetic eccentric knee extensions

1 session

1 visit (in-person)

Post-Exercise Rest

Participants rest for 3 hours post-exercise before a second muscle biopsy is taken

3 hours

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the exercise intervention

1 week

Treatment Details

Interventions

• Eccentric resistance-exercise

Trial Overview The study is testing the body's response, specifically looking at inflammation markers called myokines, released by thigh muscles after a session of eccentric resistance-exercise using specialized gym equipment known as an isokinetic dynamometer.

Participant Groups

Group I: Eccentric Exercise Experimental Treatment 1 Intervention

300 repetitions of isokinetic dynamometer eccentric knee extensions.

Who Is Running the Clinical Trial?

University of Manitoba

Lead Sponsor

Trials

628

Recruited

209,000+

Findings from Research

A study involving 22 institutionalized elders showed that high-intensity resistance training (80% of 1-repetition maximum) significantly improved knee extensor strength, endurance, and functional performance compared to low-moderate intensity training (40%) and a placebo group.

High-intensity training not only led to greater strength gains but also resulted in significant improvements in functional activities like stair climbing and walking distance, indicating that higher intensity training is both safe and more effective for enhancing physical function in frail older adults.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Physiological and functional responses to low-moderate versus high-intensity progressive resistance training in frail elders. Seynnes, O., Fiatarone Singh, MA., Hue, O., et al.[2022]

The Cybex 6000 isokinetic dynamometer demonstrated high reliability in measuring knee muscle performance, particularly showing peak torque with an interclass correlation coefficient (ICC) ranging from 0.82 to 0.91 across 30 subjects with no prior knee injuries.

Testing at a speed of 120 degrees s-1 yielded better reliability scores for all measured variables, indicating that this dynamometer is effective for both concentric and eccentric muscle performance assessments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Eccentric and concentric isokinetic knee flexion and extension: a reliability study using the Cybex 6000 dynamometer. Li, RC., Wu, Y., Maffulli, N., et al.[2022]

Unilateral eccentric-only training significantly increased eccentric strength in both the trained limb (29% increase) and the untrained limb (17% increase) after eight weeks of training, indicating a cross-training effect.

The gains in eccentric strength were maintained even after eight weeks of detraining, suggesting that this type of training can lead to lasting improvements in muscle strength.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of eccentric-only resistance training and detraining. Housh, TJ., Housh, DJ., Weir, JP., et al.[2004]

A novel eccentric (ECC) overload flywheel resistance exercise program significantly improved muscle power and function in chronic stroke patients, with peak power increasing by 34% in the affected leg after 8 weeks of training.

Participants also showed improvements in balance, gait, and overall functional performance, as evidenced by better scores on tests like the Berg Balance Scale and Timed-Up-and-Go, indicating that this exercise method is both effective and safe for stroke rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Chronic stroke patients show early and robust improvements in muscle and functional performance in response to eccentric-overload flywheel resistance training: a pilot study. Fernandez-Gonzalo, R., Nissemark, C., Åslund, B., et al.[2018]

Eccentric exercise, which involves lengthening muscles under tension, has been shown to improve both concentric (shortening) and eccentric strength, although the effects can vary and are not always velocity-specific.

Isokinetic dynamometers, which measure muscle strength during eccentric actions, may lead to less muscle soreness compared to other exercise types, suggesting potential benefits for rehabilitation and injury prevention, but more research is needed in clinical applications.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Isokinetic eccentric exercise. Kellis, E., Baltzopoulos, V.[2018]

Researchers in resistance training studies often lack clear guidance and motivation for thorough adverse event (AE) reporting, which can lead to inconsistent practices.

There is a need for exercise-specific guidelines for AE reporting, as current standards are perceived as not applicable to exercise trials, highlighting the importance of tailored strategies to improve reporting consistency.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Researchers' perspectives on adverse event reporting in resistance training trials: a qualitative study. El-Kotob, R., Pagcanlungan, JR., Craven, BC., et al.[2022]

In a study involving 15 resistance-trained men, both concentric (CON) and eccentric (ECC) exercises led to similar losses in isometric strength, indicating that both types of exercise can impact muscle strength.

However, ECC exercise resulted in a greater loss of force steadiness compared to CON, suggesting that ECC exercises may impair the ability to maintain a steady force output even in trained individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute effects of concentric vs. eccentric exercise on force steadiness and electromyographic responses of the forearm flexors. Ye, X., Beck, TW., Wages, NP.[2018]

In a 9-week study involving 31 healthy subjects, isoload (IL) eccentric resistance training significantly improved quadriceps strength and muscle structure compared to isokinetic (IK) training, with increases in eccentric strength at short muscle lengths by 20% and muscle thickness by 10%.

The study suggests that the greater torque and angular velocities achieved during IL training are key factors driving these neuromuscular adaptations, highlighting the potential of IL training for optimizing resistance training and rehabilitation programs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuromuscular adaptations to isoload versus isokinetic eccentric resistance training. Guilhem, G., Cornu, C., Maffiuletti, NA., et al.[2016]

The study demonstrated that the Exerbotics eSQ provides moderate-to-high reliability for measuring peak and mean force during maximal concentric and eccentric squats in 17 resistance-trained men, indicating it is a dependable tool for performance assessment.

Test-retest reliability statistics showed no significant differences between trials, with intraclass correlation coefficients ranging from 0.696 to 0.804, suggesting consistent results across multiple testing sessions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Consistency of peak and mean concentric and eccentric force using a novel squat testing device. Stock, MS., Luera, MJ.[2022]

Isokinetic dynamometers, like the Biodex, can effectively measure increased muscle stiffness after eccentric exercises, as shown by a 52% increase in passive resistive torque (PRT) in a study of nine young women.

This method provides a promising way to assess group changes in muscle stiffness due to eccentric exercise, but further research is needed to confirm its reliability for individual assessments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Passive resistive torque of the plantar flexors following eccentric loading as assessed by isokinetic dynamometry. Porter, MM., Andersson, M., Hellström, U., et al.[2013]

In a study involving 22 young men, both isoload (IL) and isokinetic (IK) eccentric exercises resulted in similar levels of muscle damage and neuromuscular function changes, indicating that the type of resistance exercise may not significantly affect acute muscle responses.

Both exercise modalities led to comparable decreases in voluntary isometric peak torque, muscle soreness, and creatine kinase activity, suggesting that either method can be effectively used without major differences in immediate muscle recovery outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuromuscular Changes and Damage after Isoload versus Isokinetic Eccentric Exercise. Doguet, V., Nosaka, K., Plautard, M., et al.[2018]

References

1. United States pubmed.ncbi.nlm.nih.gov

Physiological and functional responses to low-moderate versus high-intensity progressive resistance training in frail elders. [2022]

2. England pubmed.ncbi.nlm.nih.gov

Eccentric and concentric isokinetic knee flexion and extension: a reliability study using the Cybex 6000 dynamometer. [2022]

3. Germany pubmed.ncbi.nlm.nih.gov

Effects of eccentric-only resistance training and detraining. [2004]

4. England pubmed.ncbi.nlm.nih.gov

Chronic stroke patients show early and robust improvements in muscle and functional performance in response to eccentric-overload flywheel resistance training: a pilot study. [2018]

5. New Zealand pubmed.ncbi.nlm.nih.gov

Isokinetic eccentric exercise. [2018]

6. Canada pubmed.ncbi.nlm.nih.gov

Researchers' perspectives on adverse event reporting in resistance training trials: a qualitative study. [2022]

7. United States pubmed.ncbi.nlm.nih.gov

Acute effects of concentric vs. eccentric exercise on force steadiness and electromyographic responses of the forearm flexors. [2018]

8. United States pubmed.ncbi.nlm.nih.gov

Neuromuscular adaptations to isoload versus isokinetic eccentric resistance training. [2016]

9. United States pubmed.ncbi.nlm.nih.gov

Consistency of peak and mean concentric and eccentric force using a novel squat testing device. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Passive resistive torque of the plantar flexors following eccentric loading as assessed by isokinetic dynamometry. [2013]

11. United States pubmed.ncbi.nlm.nih.gov

Neuromuscular Changes and Damage after Isoload versus Isokinetic Eccentric Exercise. [2018]