Resistance Exercise for Muscle Growth

Overseen By Andrew McKiel, MSc

Age: < 65

Sex: Any

Trial Phase: Academic

Sponsor: Brock University

Must not be taking: Muscle function drugs

Disqualifiers: Diabetes, Heart, Breathing, Seizures, others

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

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 4

60 Participants Needed

Trial Summary

Will I have to stop taking my current medications?

The trial requires that participants have not taken any medications in the past year that may affect muscle function, so you may need to stop taking certain medications to participate.

What data supports the effectiveness of the treatment Resistance Exercise Training for muscle growth?

Research shows that resistance training can improve muscle strength and size in various groups, including those with chronic conditions like COPD and cancer. Studies indicate that resistance exercise helps maintain muscle mass and strength, which are crucial for overall health and quality of life. ^{1 2 3 4 5}

Is resistance exercise generally safe for humans?

Resistance exercise is generally safe for humans, with serious adverse events being uncommon. It is effective and safe for improving muscle strength and health outcomes, especially when properly supervised and tailored to individual needs. ^{6 7 8 9 10}

How does resistance exercise training differ from other treatments for muscle growth?

Resistance exercise training is unique because it stimulates muscle growth by activating specific pathways in the body that increase protein synthesis, especially when combined with protein intake after exercise. Unlike other treatments, it can be tailored to different intensity levels, such as high-load or low-load with blood flow restriction, to effectively increase muscle size and strength. ^{8 10 11 12 13}

What is the purpose of this trial?

Resistance exercise training (RET) in children and adolescents has become a popular area of research, with a growing body of evidence supporting its use. Position and consensus statements about RET for children indicate that it is safe and effective at increasing muscular strength, improving sport performance, and mitigating injury risk. Neural and muscular mechanisms can improve muscle strength following RET. Neural factors include improved recruitment and firing of an individual's motor units, and muscular factors primarily include an increase in the size of the muscle (hypertrophy). In children, little is known about how these mechanisms relate to muscle strength. There is very little evidence of morphological changes following RET in children. Therefore, conventional wisdom is that children rely only on neural factors to improve strength following RET. Nevertheless, some studies have suggested RET-induced muscle hypertrophy in children and adolescents, indicating that with certain training protocols, children may achieve muscle growth. Hypertrophy of muscle fibres occurs when the rate of muscle protein synthesis (MPS) is greater than the rate of protein breakdown, and is enhanced with the ingestion of dietary amino acids. Due to ethical concerns with obtaining muscle samples (i.e., from muscle biopsies) in pediatric populations, MPS rates have not been previously assessed following RET in children. Recent advancements in stable-isotope methodology (specifically, leucine) allow for the estimation of MPS in a non-invasive breath test. The objective of the proposed research is to examine the effects of an acute bout of RET on leucine retention (a proxy for MPS) in children, adolescents, and adults using a non-invasive breath test.

Research Team

Bareket Falk, PhD

Principal Investigator

Brock University

Eligibility Criteria

This trial is for healthy children, adolescents, and adults who can safely perform resistance exercise without any injury that would prevent them from doing so. It's not suitable for those with injuries affecting their ability to engage in such physical activity.

Inclusion Criteria

I am in good health.

I have no injuries that stop me from doing strength training.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

1 visit (in-person)

Familiarization and Baseline Testing

Participants and guardians are informed about the study, consent is obtained, and baseline measurements and familiarization with exercises are conducted.

1 day

1 visit (in-person)

Experimental Sessions

Participants undergo resistance exercise training (RET) and rest sessions in a counterbalanced order, with breath samples collected to measure leucine retention.

2 days

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the experimental sessions.

2-4 weeks

Treatment Details

Interventions

• Resistance Exercise Training

Trial Overview The study investigates the effects of a single session of resistance exercise on muscle protein synthesis (MPS) in different age groups. It uses a non-invasive breath test to measure leucine retention as an indicator of MPS.

Participant Groups

Group I: Protein supplementation Experimental Treatment 1 Intervention

Protein supplementation

Who Is Running the Clinical Trial?

Brock University

Lead Sponsor

Trials

41

Recruited

6,500+

University of Toronto

Collaborator

Trials

739

Recruited

1,125,000+

Findings from Research

A 16-week upper-body resistance training program combined with a self-efficacy intervention led to a 46% increase in muscle strength in COPD patients, compared to a 36% increase with health education alone, highlighting the efficacy of targeted resistance training.

Participants in the resistance training groups maintained 21-24% of their strength gains over 12 months of home maintenance, while those doing gentle chair exercises lost strength, indicating that resistance training is effective for long-term strength retention in COPD.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Upper-Body Resistance Training and Self-Efficacy Enhancement in COPD. Covey, MK., McAuley, E., Kapella, MC., et al.[2021]

Whole-body resistance training during hospitalization significantly improved lower-limb muscle strength and the 6-minute walking distance (6MWD) in patients with chronic obstructive pulmonary disease, with benefits observed both during and 30 days post-hospitalization.

Patients who participated in the training also reported better health-related quality of life (HRQOL) after hospitalization, while no changes in systemic inflammation levels were noted, indicating that resistance training can enhance recovery without increasing inflammation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of resistance training in chronic obstructive pulmonary disease patients during periods of acute exacerbation. Borges, RC., Carvalho, CR.[2022]

Elastic band resistance exercise training (EB-RET) significantly increased integrated myofibrillar protein synthesis (iMyoPS) in young males but did not produce the same effect in older males, suggesting age-related differences in muscle adaptive responses.

Despite the lack of increase in iMyoPS in older males, EB-RET activated similar anabolic signaling pathways in both young and older participants, indicating that while the muscle's response may be impaired with age, the signaling mechanisms are still engaged.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Myofibrillar Protein Synthesis and Acute Intracellular Signaling with Elastic Band Resistance Exercise in Young and Older Men. Marshall, RN., Morgan, PT., Smeuninx, B., et al.[2023]

Resistance training (RT) significantly improves muscular strength in elderly cancer patients, with a strong effect size of 0.87 based on a review of 13 studies involving 717 participants.

However, RT does not significantly increase muscle hypertrophy, indicating that while strength gains are achievable, increases in muscle size may not occur in this population.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of resistance training on muscular strength and hypertrophy in elderly cancer patients: A systematic review and meta-analysis. Lee, J.[2022]

Resistance exercise (RE) significantly improves lower-limb muscular strength in cancer patients undergoing neoadjuvant or adjuvant therapy, with an average increase of 26.22 kg compared to controls.

RE also leads to increases in lean body mass (0.8 kg) and decreases in body fat (-1.3 kg), making it an effective strategy to combat muscle loss and improve overall health during cancer treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of resistance training to improve muscular strength and body composition in cancer patients undergoing neoadjuvant and adjuvant therapy: a meta-analysis. Padilha, CS., Marinello, PC., Galvão, DA., et al.[2022]

Resistance training (RT) significantly reduces all-cause mortality and the incidence of cardiovascular disease while improving physical functioning in adults, based on an analysis of 11 systematic reviews involving over 382,000 participants.

Although adverse events were not consistently reported, serious adverse events related to RT were uncommon, suggesting that the benefits of resistance training outweigh the potential harms.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Resistance training and health in adults: an overview of systematic reviews. El-Kotob, R., Ponzano, M., Chaput, JP., et al.[2021]

Resistance training is a safe and effective method for improving muscle strength and aerobic endurance, particularly beneficial for healthy adults, the elderly, and patients with cardiac and pulmonary conditions.

Proper assessment and tailored exercise programs enhance the safety and long-term effectiveness of resistance training, contributing to better health outcomes and reduced risk factors for cardiovascular and metabolic diseases.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

[Resistance (strength) training in health promotion and rehabilitation]. Kostka, T.[2006]

Ten weeks of resistance training can lead to significant health benefits, including an increase in lean muscle mass by 1.4 kg, a 7% boost in resting metabolic rate, and a reduction in fat weight by 1.8 kg.

Resistance training not only improves physical performance and cognitive abilities but also helps in managing type 2 diabetes and enhancing cardiovascular health by reducing visceral fat and improving cholesterol levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Resistance training is medicine: effects of strength training on health. Westcott, WL.[2022]

Regular weight-training can lead to positive adaptations in cardiovascular health, including decreased heart rate during maximal work and improved myocardial structure, which may help reduce the risk of cardiovascular disease.

Resistance training can also enhance aerobic capacity and improve metabolic health markers like glucose tolerance and insulin sensitivity, although caution is advised for individuals with existing cardiovascular conditions due to potential blood pressure responses.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Health- and performance-related potential of resistance training. Stone, MH., Fleck, SJ., Triplett, NT., et al.[2022]

High intensity resistance training can effectively increase strength in preadolescents, with children showing similar percentage improvements in strength as adolescents, but with smaller absolute gains.

When properly supervised, resistance training poses a low risk of injury for preadolescents and does not negatively impact growth, body composition, or cardiorespiratory fitness.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Resistance training during preadolescence. Issues and controversies. Blimkie, CJ.[2018]

Progressive high-resistance exercise, especially with 8-12 repetitions to near failure, can significantly boost muscle protein synthesis for up to 72 hours, particularly when combined with approximately 20 grams of protein intake immediately after exercise.

Muscle growth is primarily regulated by the mTOR signaling pathway, which responds to various factors like IGF-1, mechanical signals, and amino acids, while its action is countered by myostatin signaling that inhibits growth.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Signal transduction pathways that regulate muscle growth. Wackerhage, H., Ratkevicius, A.[2021]

After 6 weeks of training, both moderate load (ML) and low-load blood flow restricted (BFR) resistance exercises improved strength and muscle size in young adults, with ML showing greater effectiveness.

Isometric peak torque and neuromuscular function did not significantly change in any group, suggesting that while strength and hypertrophy were achieved, further research is needed to understand the underlying neuromuscular adaptations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Neuromuscular Adaptations to Low-Load Blood Flow Restricted Resistance Training. Cook, SB., Scott, BR., Hayes, KL., et al.[2019]

In a study involving 64 young resistance-trained men over 8 weeks, resistance training with higher velocity loss thresholds (20% and 40%) led to significant increases in muscle hypertrophy, indicating that these thresholds can enhance muscle growth.

However, the highest threshold (40%) also resulted in negative neuromuscular adaptations, such as a slower rate of force development, suggesting that moderate velocity loss thresholds are preferable for maximizing strength gains while minimizing adverse effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Velocity Loss as a Critical Variable Determining the Adaptations to Strength Training. Pareja-Blanco, F., Alcazar, J., Sánchez-Valdepeñas, J., et al.[2021]

References

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

Upper-Body Resistance Training and Self-Efficacy Enhancement in COPD. [2021]

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

Impact of resistance training in chronic obstructive pulmonary disease patients during periods of acute exacerbation. [2022]

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

Myofibrillar Protein Synthesis and Acute Intracellular Signaling with Elastic Band Resistance Exercise in Young and Older Men. [2023]

4. China pubmed.ncbi.nlm.nih.gov

The effects of resistance training on muscular strength and hypertrophy in elderly cancer patients: A systematic review and meta-analysis. [2022]

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

Evaluation of resistance training to improve muscular strength and body composition in cancer patients undergoing neoadjuvant and adjuvant therapy: a meta-analysis. [2022]

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

Resistance training and health in adults: an overview of systematic reviews. [2021]

7. Poland pubmed.ncbi.nlm.nih.gov

[Resistance (strength) training in health promotion and rehabilitation]. [2006]

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

Resistance training is medicine: effects of strength training on health. [2022]

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

Health- and performance-related potential of resistance training. [2022]

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

Resistance training during preadolescence. Issues and controversies. [2018]

11. England pubmed.ncbi.nlm.nih.gov

Signal transduction pathways that regulate muscle growth. [2021]

12. Turkey pubmed.ncbi.nlm.nih.gov

Neuromuscular Adaptations to Low-Load Blood Flow Restricted Resistance Training. [2019]

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

Velocity Loss as a Critical Variable Determining the Adaptations to Strength Training. [2021]