Velocity-Based Exercise for Muscle Weakness

Overseen By Lance Bollinger, PhD

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: Lance Bollinger

Must not be taking: Sleep aids, Oral contraceptives

Disqualifiers: Blood clotting disorder, Heart arrhythmia, Cardiovascular disease, others

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

Compensation: Varies

Number of Visits: 16

16 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how flywheel-based inertial training (FIT) affects muscle weakness and fitness loss from limb disuse. It examines how this exercise can enhance muscle strength, aerobic fitness, and balance. Individuals who regularly work out and hold a bachelor's degree in any field might be suitable candidates. Participants will either refrain from exercise or engage in this specific exercise while one leg is temporarily suspended. As an unphased trial, this study provides a unique opportunity to contribute to innovative exercise research that could enhance rehabilitation techniques.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but you cannot participate if you are currently taking medication to assist with sleep.

What prior data suggests that this exercise protocol is safe?

Studies have shown that flywheel-based inertial training (FIT) is generally safe and easy to handle. Research indicates that rehabilitation programs use this type of exercise, particularly for individuals recovering from knee injuries. This suggests that FIT can aid muscle recovery without causing harm. Another study found that FIT helped older adults enhance their physical and muscle function. These studies reported no major safety concerns. Overall, the evidence suggests that FIT is a safe exercise option for improving strength and other physical abilities. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about velocity-based FIT (VBFIT) exercise because it offers a unique approach to tackling muscle weakness. Unlike traditional exercise routines that often focus on intensity or volume, VBFIT emphasizes the speed of movement, potentially leading to faster and more efficient muscle adaptations. This method could be particularly beneficial during periods of muscle disuse, such as with Unilateral Lower Limb Suspension (ULLS), by maintaining muscle strength and function more effectively than current methods. Additionally, the VBFIT approach could redefine rehabilitation by providing a more dynamic and engaging exercise protocol, which may enhance compliance and outcomes for patients experiencing muscle weakness.

What evidence suggests that velocity-based FIT exercise is effective for muscle weakness?

Studies have shown that flywheel-based inertial training (FIT) can enhance muscle strength, power, and speed. Research on well-trained male college athletes found that this type of training significantly increased lower-body strength. A review of various studies also found that flywheel training led to physical and functional improvements in older adults. This trial will compare two groups: one group will undergo a 30-day Unilateral Lower Limb Suspension (ULLS) with velocity-based FIT (VBFIT) exercise, while the other group will undergo ULLS without exercise. This suggests that FIT could help reduce muscle weakness and improve balance and endurance. Overall, the evidence supports the potential effectiveness of FIT for addressing muscle issues caused by inactivity. ^{1 5 6 7 8}

Who Is on the Research Team?

Lance Bollinger, PhD

Principal Investigator

University of Kentucky

Are You a Good Fit for This Trial?

This trial is for individuals who regularly exercise, both aerobically (>150 minutes per week) and with resistance training (>1 time per week), for the past year and have at least a bachelor's degree. It does not specify who cannot join.

Inclusion Criteria

Regularly engaging in aerobic exercise (> 150min/wk) and resistance exercise (>1 time per week) for the past 12 months

Education greater than or equal to bachelor's degree (any field)

Exclusion Criteria

Oral contraceptive use (within previous three months)

I have an irregular heartbeat.

My waist is either less than or more than the required size for my gender.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Unilateral Lower Limb Suspension (ULLS)

Participants undergo 30 days of unilateral lower limb suspension to simulate muscle disuse, with or without Flywheel-based Inertial Training (FIT)

4 weeks

3 visits per week for exercise group

Testing and Assessment

Participants complete a series of tests including body composition, balance assessment, aerobic capacity test, muscle imaging, and muscle strength testing

Throughout the intervention period

Baseline, day 13, and day 30 assessments

Follow-up

Participants are monitored for safety and effectiveness after the intervention

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• FIT Exercise

Trial Overview

The study tests how velocity-based flywheel inertial training (VBFIT), which combines principles of high-intensity interval training (HIIT) and velocity-based exercises, affects muscle strength, aerobic capacity, and balance during periods without regular use of muscles.

How Is the Trial Designed?

Group I: velocity-based FIT (VBFIT) Experimental Treatment 1 Intervention

Participants will undergo a 30d Unilateral Lower Limb Suspension (ULLS) with exercise

Group II: No Exercise Active Control 1 Intervention

Participants will undergo a 30d Unilateral Lower Limb Suspension (ULLS) without exercise

Who Is Running the Clinical Trial?

Lance Bollinger

Lead Sponsor

Trials

2

Recruited

30+

National Aeronautics and Space Administration (NASA)

Collaborator

Trials

32

Recruited

1,900+

University of Louisville

Collaborator

Trials

353

Recruited

76,400+

Published Research Related to This Trial

In a study involving 15 healthy males, increasing flywheel inertia during half-squats led to a decrease in both peak and mean velocities, indicating that heavier inertia may slow down movement performance.

The study suggests that velocity is a more important measure than power for prescribing and monitoring flywheel squat intensities, and that individualized inertia-velocity relationships can help optimize training.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Concentric and eccentric inertia-velocity and inertia-power relationships in the flywheel squat. McErlain-Naylor, SA., Beato, M.[2021]

The study validated a low-cost friction encoder for measuring velocity, force, and power in flywheel exercises, showing it provides reliable results compared to a more expensive strain gauge system, with nearly perfect correlations across all measures.

While the friction encoder is effective, some moderate biases were noted, suggesting that consistent testing protocols are essential for tracking changes over time or comparing different individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validity of a low-cost friction encoder for measuring velocity, force and power in flywheel exercise devices. Illera-Domínguez, V., Fernández-Valdés, B., Gisbert-Orozco, J., et al.[2023]

A 12-week low-load blood-flow restricted (BFR) resistance training program improved knee extensor strength in the stronger leg of patients with sporadic inclusion body myositis (sIBM), while non-exercising patients experienced a decline in strength.

BFR training may help slow down the decline in muscle function associated with sIBM, highlighting its potential clinical importance in preserving physical function for these patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of blood-flow restricted resistance training on mechanical muscle function and thigh lean mass in sIBM patients. Jørgensen, AN., Jensen, KY., Nielsen, JL., et al.[2022]

This study identified key physical activity measures using 3D accelerometry that could serve as sensitive endpoints in clinical trials for children with mitochondrial disease, based on data from 17 patients and 16 controls.

Children with mitochondrial disorders exhibited significantly lower peak activity levels and spent more time resting compared to their peers, highlighting the need for user-friendly devices to accurately measure these activity domains in future research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Domains of Daily Physical Activity in Children with Mitochondrial Disease: A 3D Accelerometry Approach. Koene, S., Dirks, I., van Mierlo, E., et al.[2020]

A 12-week low-load resistance exercise program with blood flow restriction (BFR) significantly improved mechanical muscle function and gait speed in a patient with sporadic inclusion body myositis (sIBM).

The patient experienced a 19% increase in maximal horizontal gait speed and 38-92% improvements in various measures of muscle function, indicating that BFR training is a well-tolerated and effective intervention for enhancing physical capabilities in sIBM.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of blood-flow-restricted resistance training on muscle function in a 74-year-old male with sporadic inclusion body myositis: a case report. Jørgensen, AN., Aagaard, P., Nielsen, JL., et al.[2022]

In a multicenter trial involving 30 participants with neuromuscular diseases, a strong correlation (over 0.70) was found between heart rate and perceived exertion during maximal exercise testing, indicating that heart rate can be a reliable measure of exertion in these individuals.

However, during home-based aerobic training, many participants reported different levels of perceived exertion for the same heart rates compared to testing, suggesting that healthcare professionals need to consider these differences to avoid under- or over-training.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Relationship Between Heart Rate and Perceived Exertion in Neuromuscular Diseases: How do Laboratory-Based Exercise Testing Results Translate to Home-Based Aerobic Training Sessions? Voorn, EL., Oorschot, S., Veneman, T., et al.[2023]

The Inertial Measurement System (IMS) demonstrated high validity and reliability for measuring linear velocity during flywheel squat exercises in a study with 31 experienced male participants.

The IMS showed excellent agreement with a validated linear encoder, indicating it can be a trustworthy tool for assessing movement velocity in resistance training.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validity and Reliability of Inertial Measurement System for Linear Movement Velocity in Flywheel Squat Exercise. Maroto-Izquierdo, S., Nosaka, K., Alarcón-Gómez, J., et al.[2023]

The study involving 25 physically active men demonstrated a strong correlation between inertial load and mean concentric linear velocity (MCLV) during flywheel squat exercises, suggesting that MCLV can effectively quantify training load and personalize flywheel training prescriptions.

The research also found that the subjective rating of perceived exertion (RPE) is a reliable measure, correlating significantly with both load and MCLV, indicating that RPE can be used as an alternative method to monitor and control flywheel training intensity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Use of concentric linear velocity to monitor flywheel exercise load. Martín-Rivera, F., Beato, M., Alepuz-Moner, V., et al.[2022]

A study involving 24 high-level handball players found that at least 3 sessions are necessary for familiarization with flywheel quarter-squat exercises to stabilize performance outcomes.

Using a lower inertial load of 0.025 kg·m2 resulted in higher concentric peak power, while medium to high loads (0.050 to 0.100 kg·m2) were better for achieving greater eccentric power, indicating that different loads can optimize specific aspects of strength training.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of Different Inertial Loads on Basic Training Variables During the Flywheel Squat Exercise. Sabido, R., Hernández-Davó, JL., Pereyra-Gerber, GT.[2018]

In a study involving 16 patients with neuromuscular disorders, high-resistance weight training led to significant improvements in muscle performance, with maximum force increasing by an average of 80% and work done (force-time integral) increasing by 132%.

Patients with initial muscle strength greater than 15% of normal showed notable benefits, while those with severely weak muscles (less than 10% normal strength) did not experience improvements, indicating that the effectiveness of weight training is dependent on the initial strength level and disease progression.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Muscle strengthening through high-resistance weight training in patients with neuromuscular disorders. Milner-Brown, HS., Miller, RG.[2006]

In a study involving 36 healthy older adults, 6 weeks of flywheel resistance training significantly improved muscle strength and power, particularly in knee flexion, compared to a control group.

Participants in the flywheel training group also showed enhanced physical function, as evidenced by better performance in the 30-second Chair Sit-Stand Test, indicating that this training method is effective for increasing functional capacity in older adults.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Improved Muscle Strength, Muscle Power, and Physical Function After Flywheel Resistance Training in Healthy Older Adults: A Randomized Controlled Trial. Sañudo, B., de Hoyo, M., McVeigh, JG.[2023]

The Elite Form Training System® (EFTS) demonstrated excellent validity and reliability for measuring peak and average velocity, as well as peak and average power during various resistance exercises, with correlation coefficients ranging from 0.868 to 0.998 across six different exercises.

The test-retest reliability of the EFTS showed minimal variation between sessions, indicating that it consistently provides accurate measurements, making it a reliable tool for velocity-based training in resistance exercises.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validity and reliability assessment of 3-D camera-based capture barbell velocity tracking device. Tomasevicz, CL., Hasenkamp, RM., Ridenour, DT., et al.[2020]

Perceived velocity loss (PVL) can be a reliable method for monitoring resistance training, showing an average error of only 1 repetition when compared to actual velocity loss measurements in a study of 26 resistance-trained men.

PVL accuracy is highest when using moderate loads (around 50-60% of 1-repetition maximum), making it a practical alternative for training prescription when velocity-tracking devices are not available.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perception of Bar Velocity Loss in Resistance Exercises: Accuracy Across Loads and Velocity Loss Thresholds in the Bench Press. Dello Iacono, A., Watson, K., Marinkovic, M., et al.[2023]

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frontiersin.org/journals/public-health/articles/10.3389/fpubh.2025.1579291/full

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This study investigates optimal FRT loading for specific training goals (maximal strength, power, muscular endurance) by analyzing concentric velocity at ...

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New Perspectives for the Resistance Training of Runners

Flywheel-based inertial training (FIT) has been used as a countermeasure to preserve muscle strength and size. The objective of this study ...