Resistance Exercise for Metabolism

(TIMER Trial)

Overseen By John McCarthy, Ph.D.

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: Yuan Wen

Must not be taking: Aspirin, NSAIDs, Anticoagulants

Disqualifiers: Cardiovascular disease, Metabolic syndrome, Neurological, others

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

Compensation: Varies

Number of Visits: 1

Duration: 1 day

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to understand how resistance exercises affect the release of a specific molecule, miR-1, from muscles and whether it travels to fat tissue. Participants will perform high-intensity exercises like squats and leg presses. The trial seeks young adults with a BMI under 25 or over 30, who do not exercise regularly and are non-smokers. This research could reveal how exercise impacts metabolism, especially in less active individuals. As an unphased trial, participants can contribute to groundbreaking research on exercise and metabolism.

Will I have to stop taking my current medications?

The trial requires that you stop taking chronic aspirin or NSAIDs (pain relievers) unless it can be safely stopped before the biopsies. If you are on any anticoagulants (blood thinners) or have a history of bleeding disorders, you may not be eligible to participate.

What prior data suggests that this exercise protocol is safe?

Research shows that resistance exercise is generally safe for most people. Studies have found that resistance training can improve heart health in individuals with and without heart issues. It also helps reduce body fat, particularly around the abdomen, and can assist in weight management.

Previous studies discovered that short sessions of resistance exercise, like those in this trial, increase energy expenditure and raise blood lactate levels, indicating significant physical exertion. Most people can perform these exercises without serious issues.

Overall, resistance exercise is a well-supported method to enhance health and is considered safe for many. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the Acute Resistance Exercise trial because it focuses on using targeted resistance exercises to enhance metabolism, a strategy that stands apart from traditional metabolic treatments like medication or dietary changes. This approach leverages exercises such as squats, knee extensions, leg presses, and lat pulldowns at a specific intensity (80% of one-repetition maximum) to potentially optimize metabolic function. Unlike other methods that may rely on chemical interventions, this exercise-based technique aims to harness the body's natural physical capabilities to improve metabolic health, offering a non-invasive, active alternative that could be more sustainable and engaging for participants.

What evidence suggests that acute resistance exercise is effective for metabolism?

Research shows that resistance exercise, such as the acute resistance exercise studied in this trial, can improve overall health. Studies have found that it helps build muscle and manage blood sugar levels by enhancing the body's use of sugar. After exercise, the body can continue to burn more calories for up to 38 hours, increasing overall energy expenditure. Resistance training also reduces the risk of heart disease and can extend lifespan. This type of exercise improves body shape and can be an important part of a health program. ^{2 3 6 7 8}

Who Is on the Research Team?

John McCarthy, Ph.D.

Principal Investigator

University of Kentucky

Yuan Wen, Ph.D.

Principal Investigator

University of Kentucky

Are You a Good Fit for This Trial?

This trial is for young adults aged 18-30 who are healthy or obese (BMI <25 or >30), non-smokers, and haven't been exercising regularly. It's not for those taking certain blood thinners, with bleeding disorders, metabolic syndromes like diabetes, heart issues, pregnant women, or anyone with a lidocaine allergy.

Inclusion Criteria

Non-smoker

Your body mass index (BMI) is either below 25 or above 30.

You have not been regularly exercising (at least one day per week) for the past 3 months and are mostly inactive.

Exclusion Criteria

Chronic aspirin or NSAID use (unless it can be safely stopped prior to the biopsies), and any other use of an anticoagulant (e.g., Coumadin) or history of bleeding including history of hypo- or hyper-coagulation disorders

Any other medical condition that would interfere with testing or increase one's risk of complications during exercise, as judged by the study physician

Any other condition or events considered exclusionary by the PI and/or physician, such as non-compliance

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants perform acute resistance exercise including squat, knee extension, leg press, and lat pulldown at 80% of 1-RM

1 day

1 visit (in-person)

Follow-up

Participants are monitored for miR-1 abundance in exosomal, muscle, and adipose tissue following exercise

90 minutes

What Are the Treatments Tested in This Trial?

Interventions

• Acute Resistance Exercise

Trial Overview The study looks at how muscle releases tiny vesicles containing miR-1 into the fat tissue after one session of resistance exercise. The focus is on comparing this process between healthy and obese participants.

How Is the Trial Designed?

Group I: Acute Resistance Exercise Experimental Treatment 1 Intervention

Participants will perform four exercises: squat, knee extension, leg press, and lat pulldown at 80% of 1-RM determined during a previous visit.

Who Is Running the Clinical Trial?

Yuan Wen

Lead Sponsor

Trials

1

Recruited

40+

John McCarthy

Lead Sponsor

Trials

1

Recruited

40+

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Collaborator

Trials

2,513

Recruited

4,366,000+

Published Research Related to This Trial

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]

A systematic review of 12 studies indicates that while there is some evidence suggesting children and adolescents can gain metabolic health benefits from supervised resistance training, the evidence is limited and not definitive.

The current research has methodological limitations, highlighting the need for better-designed randomized controlled trials to accurately assess the effects of resistance training on metabolic health in young populations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of resistance training on metabolic fitness in children and adolescents: a systematic review. Benson, AC., Torode, ME., Fiatarone Singh, MA.[2018]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11966053/

The effectiveness of metabolic resistance training versus ... When properly structured, MRT can elevate post-exercise oxygen consumption for up to 38 h after training, substantially increasing total energy ...

2. nature.com nature.com/articles/s41598-025-11076-w

Effects of resistance training and aerobic ... Studies indicate that resistance training improves muscle mass, enhances glucose metabolism, and reduces risk factors for metabolic syndrome, ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9142957/

Effects of Acute and Chronic Resistance Exercise on the ... Comparison of post-exercise metabolite levels between trained and untrained state revealed alterations of 46 metabolites, including decreased N-acetylated ...

4. ahajournals.org ahajournals.org/doi/10.1161/CIR.0000000000001189

Resistance Exercise Training in Individuals With and ... Adults who participate in RT have ≈15% lower risk of all-cause mortality and 17% lower risk of CVD, compared with adults who report no RT.

5. onlinelibrary.wiley.com onlinelibrary.wiley.com/doi/10.1111/obr.13428

Resistance training effectiveness on body composition and ... This study provides evidence that resistance-based exercise programs are effective and should be considered within any multicomponent therapy program.

6. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC3168930/

Resistance Training Is an Effective Tool against Metabolic and ... Resistance training has favourable effect on metabolic syndrome since it decreases fat mass including abdominal fat. It also enhances insulin sensitivity.

7. frontiersin.org frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2025.1551624/full

Acute effects of resistance exercise intensity and repetition ... These findings highlight that acute RE, regardless of intensity, enhances IC and raises blood lactate when exercise volume is controlled.

8. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC9716768/

Resistance exercise training-induced skeletal muscle ... Resistance exercise-trained mice had a lean phenotype and counteracted diet-induced obesity and glucose tolerance, even after exercise cessation.