Reversing Muscle Loss With Exercise Training and Daily Consumption of Pomegranate Juice

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.

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