Hypertrophy, Mitochondria, Strength
Conditions
Brief summary
Blood flow restricted (BFR) exercise has been shown to improve skeletal muscle adaptations to resistance exercise. BFR uses blood pressure cuffs (i.e., tourniquets) to reduce skeletal muscle blood flow during resistance exercise. One benefit of BFR is that skeletal muscle adaptations to resistance exercise training including muscle hypertrophy and increases in strength can be achieved at lower-loads (e.g., 25-30% 1RM), that are often comparable to more traditional resistance training loads (70-85% 1RM). However, the impact that low-load BFR resistance exercise has on muscle quality and bioenergetics is unknown. The present study will examine the impact of 6 weeks of low-load, single-leg resistance exercise training with or without personalized BFR on measures of muscle mass, strength, quality, and mitochondrial bioenergetics. The investigators will recruit and study up to 30, previously sedentary, healthy, college-aged adults (18-40 years). The investigators will measure muscle mass using Dual Energy X-Ray Absorptiometry and muscle strength and endurance using isokinetic testing. The investigators will normalize knee extensor strength to lower limb lean mass to quantify muscle quality. The investigators will also use near infrared spectroscopy (NIRS) to measure mitochondrial oxidative capacity in the vastus lateralis. Finally, the investigators will measure markers of systemic inflammation and markers of muscle damage using commercially available ELISA assays.
Interventions
BEHAVIORALLow Load Resistance Exercise
Subjects allocated to Low Load Resistance Exercise will undergo 6 weeks of single-legged low load (25%) resistance exercise. Subjects will then perform 4 sets of 30, 15, 15 and 15 repetitions at 25% of their 1RM for the single-legged leg press and single-legged knee extensions. Their contralateral leg will serve as within subject control.
BEHAVIORALLow Load Resistance Exercise + BFR
Subjects allocated to Low Load Resistance Exercise + BFR will undergo 6 weeks of single-legged low load (25%) resistance exercise with blood flow restriction (60% occlusion pressure). Subjects will then perform 4 sets of 30, 15, 15 and 15 repetitions at 25% of their 1RM for the single-legged leg press and single-legged knee extensions. Their contralateral leg will serve as within subject control.
Sponsors
Delfi, Inc.
Louisiana State University and A&M College
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
. 1. Capable and willing to give written informed consent 2. Capable of understanding inclusion and
Exclusion criteria
3. 18-40 years of age inclusive 4. Body Mass Index (BMI) between 18.5-30 kg/m2 inclusive 5. No medical condition that would limit their participation in supervised exercise training based on the Physical Activity Readiness Questionnaire for Everyone (PARQ+) 6. No current prescription medications, with the exception of birth control 7. Willing to allow researchers to use data, biospecimens (e.g., blood) and images (e.g., Dual Energy x-Ray Absorptiometry) for research purposes after study participation is completed
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Mitochondrial Oxidative Capacity | Changes from baseline (pre-training) to follow-up (about 48-72 hours post-training). | Changes in mitochondrial oxidative capacity will be measured using near infrared spectroscopy (NIRS). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Changes in Muscle Mass measured by Dual Energy X-ray Absorptiometry | Changes from baseline (pre-training) to follow-up (about 48-72 hours post-training) | Changes in muscle mass will be measured by Dual Energy X-ray Absorptiometry |
| Changes in Muscle Strength measured using Isokinetic Dynamometry | Changes from baseline (pre-training) to follow-up (about 48-72 hours post-training) | Changes in muscle strength measured using isokinetic dynamometry |
| Changes in Muscle Endurance measured using Isokinetic Dynamometry | Changes from baseline (pre-training) to follow-up (about 48-72 hours post-training) | Changes in muscle endurance measured using isokinetic dynamometry |
Countries
United States
Outcome results
None listed