Cardiovascular Risk Factor, Sarcopenia
Conditions
Keywords
Pomegranate Juice, Functional Tasks of Living
Brief summary
A research study regarding the body's response to several weeks of training using short sprints and pomegranate juice supplementation
Detailed description
The investigators have shown that chronic pomegranate juice consumption in both young untrained and weight-trained men partially protects muscles against the damage done from performing high intensity eccentric contractions and that it accelerates recovery of function. Clearly, skeletal muscle is a target for some of the healthful molecules in pomegranate juice. However, the most widespread and serious ailment to strike skeletal muscle is sarcopenia (e.g.; loss of muscle mass and becoming 'frail') with age due predominantly to a loss of 'fast-twitch' muscle fibers. Since adults rarely sprint or exert maximal force or power, they rarely use their fast-twitch muscle fibers, which thus degenerate greatly with age. Usually, about one-half of a person's muscle fibers are fast-twitch. It is the investigators' hypothesis that the combination of power exercise training and pomegranate juice supplementation (POM) over 10 weeks, will elicit greater improvements in maximal muscular power and functional physical abilities compared to power training with a placebo. The investigators also will identify changes in size and composition of leg muscles (MRI) and of the whole body (DEXA). The investigators simple logic is that muscles deteriorate with age because they are 'turned-off' and that exercise training can turn them 'back-on', but in order for the muscle fibers to fully repair when turned 'back-on' with exercise, they might benefit from agents known to foster repair, such as the natural polyphenols in pomegranate juice. It has recently been found that polyphenols are metabolized into urolithins which improve muscle cell function due to increased mitophagy. The investigators aim to determine if power training and pomegranate juice have additive effects in promoting improvements of muscle function and mass in men and women age 50-70 y. A second purpose is to include a cardio-metabolic exercise training stimulus into the workout without compromising the efficacy of the power training. One feature of cardio-metabolic training is an increase in muscle mitochondria and oxygen utilization which might improve muscle fiber repair. The 'power training' will consist of maximal effort 4 sec sprints on a cycle ergometer with no added resistance with the only load being that of the inertia of the flywheel as the subject accelerates from 0 to their maximal RPM's while cycling (100-150 RPM)('inertial load ergometer'; ILE). The power training will be accomplished by having the subject complete 15-30 sprints in a 15 min period. During the training bouts, initially the subjects will rest 56 s between sprints (week 1- complete 15 sprints in each15 min bout), and then 41 s between sprints (weeks 2-5 and complete 20 sprints) and finally 26 s between sprints (weeks 6-10 and complete 30 sprints). The shorter rest periods (41 s and 26 s) will result in incomplete recovery of the cardio-respiratory system and thus the oxygen consumption and heart rate will average 50-70% of maximal values, which is a similar intensity as jogging, but without the jarring of foot strike.
Interventions
OTHERInertial Load Cycling Training
Each session of training will require a total of 15 min with the total time actually exercising of only 60-120 sec. The first week will consist of performing 15 'sprints' on the ILE, beginning each sprint with 56 sec of rest. During week 2-5, subjects will rest 41 sec between sprints, completing 20 bouts. Finally, during weeks 6-10, subjects will take 26 s rest between sprints and complete 30 bouts).
DIETARY_SUPPLEMENTPomegranate Juice
Subjects will consume 8oz of pomegranate juice daily for duration of study.
DIETARY_SUPPLEMENTPlacebo
Subjects will consume 8oz of pomegranate juice daily, that has had the polyphenols removed.
Sponsors
POM Wonderful LLC
University of Texas at Austin
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Masking description
Pomegranate juice will be administered in double blind placebo controlled method. Coding will be established by POM Wonderful, LLC.
Eligibility
Sex/Gender
ALL
Age
50 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* 50-70 year old male and females
Exclusion criteria
* not currently exercising regularly * meets criteria for MRI scanning at Imaging Research Center at UT Austin * history of heart disease * knee/hip joint problems * determination by the physician monitoring pre inclusion stress test
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in maximal power production | Baseline to 11 weeks | The ability to produce power as determined on the cycle ergometer and measured in watts |
| Change in muscle volume | Baseline to 11 weeks | Volume of the thigh musculature as determined by MRI analysis. |
| Change in sarcopenia obesity | Baseline to 11 weeks | Intermuscular adipose tissue infiltration as measured by MRI |
| Change in aerobic capacity | Baseline to 11 weeks | VO2 Max on a cycle ergometer |
| Change in anaerobic capacity | Baseline to 11 weeks | The percent of maximal aerobic capacity that a subject can exercise at while not building up blood lactate |
| Change in muscle fatigue | Baseline to 11 weeks | Muscle aerobic stress as measured by near infrared spectroscopy |
| Change in body composition | Baseline to 11 weeks | Fat and fat free regional and total mass as measured by dual x-ray absorptiometry |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in urolithins | Baseline, 2 hrs after consuming first pomegranate or placebo supplement | The ability to breakdown the beneficial components of pomegranate juice into urolithins is different among individuals |
| Change in Microbiome | Baseline, week 10 and week 15 | The change in the gut microbiota as a result of supplementation with pomegranate juice. |
| Change in maximal isometric strength | Baseline to 11 weeks | The maximal ability to push against a immovable object as measured in the thigh musculature |
| Change in functional tests of living | Baseline to 11 weeks | Movement tasks specific to the daily life of the elderly |
| Change in isokinetic torque | Baseline to 11 weeks | The subject will exert maximal leg extension at two speeds and the maximal torque generated will be quantified |
| Change in cardiovascular risk factors | Baseline to 11 weeks | Flow mediated dilation and pulse wave velocity |
Countries
United States
Outcome results
None listed