Hypertrophy Case Studies

INTRODUCTION

In elderly individuals loss of muscle strength and mass and its associated outcomes is a common problem. With ageing the bone tends to shrink in size and the density of the bones reduces. Such osteoporotic bones are more susceptible to fracture. With all this underlying causes there is lack of coordination and trouble in balancing which leads to increase in fall risk in such elderly individuals. So it becomes crucial to address the issue of muscle growth in elderly individuals. Another common and degenerative disorder with aging is osteoarthritis of knee which is a leading cause of disabilities among older adults. Osteoarthritis occurs due to degeneration of knee joint cartilage and the underlying bone which occurs commonly in people of and above 50 years of age. The classic clinical symptoms associated with it are joint pain, stiffness and loss of muscular strength of knee musculature of which loss of quadriceps muscle mass and strength is the most common. The activities of daily living is also affected in older patients with knee osteoarthritis. Increasing strength of quadriceps muscle has a lot of benefits like protecting the joint and delaying the progression of disease.

Creatine

supplementation as well as resistance training has been shown to increase muscle strength and mass. Creatine is an organic acid which naturally produced in human body and is found in high amounts in meat. Due to this levels of creatine are significantly lower in non-vegetarian individuals. Primarily creatine helps in supplying energy to cell in body and specifically in muscles, this is achieved by formation of adenosine triphosphate (ATP) through phosphocreatine system. When there is demand of energy, as a part of phosphocreatine system phosphocreatine gives its phosphate group to adenosine diphosphate (ADP) and forms ATP which is used as energy whereas when there is ample off energy available the phosphate group from the adenosine triphosphate (ATP) combines with creatine to form phosphocreatine which serves as an energy reserve for later use.
Creatine has shown to increase muscle mass and strength. There are various mechanisms associated with it. Creatine can increase training volume by increasing energy provision by mitochondria hence provides ability to complete more repetitions. Creatine also has its effect on water retention as it has the ability to draw water into the muscle from blood and surrounding interstitial fluid. Activation of satellite cells is another such mechanism with creatine ingestion. Muscle cells are multinucleated and the size of muscle is determined by the number of nuclei it has. This nuclei sprouts from the satellite cells which are activated by creatine. It has also been shown to activate specific muscle growth factors. Research shows that creatine supplementation along with resistance training increases muscle mass and strength in older women and it also reduces the incidence of sarcopenia [1]. Another study proves that creatine can induce muscle hypertrophy and can enhance rehabilitation of the muscle after disuse atrophy. The study also showed that wit exercise training there is alteration in response of myogenin and MRF 4 protein expression also. [2]
Resistance training induces change in neural adaptations which shows changes in muscular strength and ultimately size of the muscle. With resistance exercise there is increase in the tension of the muscle which has its correlation with processes like mTOR activation or activation of satellite cells. Such pro-growth stimulus are responsible for muscle growth. With resistance exercise there is production of Insulin like growth factor (IGF) which activates PI3 kinase which in turn activates protein kinase B. This AKT or PKB inhibits TSC2. Normally TSC2 inhibits Rheb but since with training TSC2 is inhibited there is more availability of free Rheb. This free Rheb through GTP activate mTOR which promotes the growth. One other cause of muscle growth is release of inflammatory substances following muscle damage which are thought to be activating the satellite cells. Metabolic stress is also one of the determinant of muscle growth following resistance training. Several studies have shown to increase muscle strength with resistance training and also in specific with older women [3]
With strength training mainly two types of hypertrophy are produced, 1.

Myofibrillated hypertrophy and 2. Sarcoplasmic hypertrophy. Both of the categories are dependent on the load of the stimulus. With the training there is increase in neural drive which stimulates the muscle contraction. One of the main factor with hypertrophy is progressive overload, in which increasing the weight in a progressive manner can stimulate growth. So designing the protocol for training plays an important role in muscle growth in terms of hypertrophy. Resistance training with older individuals plays an important role in maintaining the muscle mass thereby preventing sarcopenia. The external resistance in strength training can be in any form like dumbbells, tubing, own body weight

etc.
With knee osteoarthritis there is specific loss of the muscle strength of quadriceps muscle which occurs due to arthrogenic muscle inhibition which affects the function of the muscle and worsens the progression of the disease. Resistance training combined with creatine supplementation could increase quadriceps muscle strength and mass in older individuals with knee osteoarthritis which could limit the progression of the disease and can alleviate joint pain and stiffness.
In the research study done by Bruno Gualano et al, the role of creatine supplementation specifically combined with resistance training in older women was examined. Along with examining the effects on muscle mass and strength, the study also focused its effects on development and differentiation of bone cells. The need of the study that the article stated that previously no studies had been carried to see the effects of creatine supplementation and resistance training in particular with older vulnerable women. The study was a 24 week double blind, randomized placebo control trial. The study was performed in the time period of July 2010 to November 2011 in Sao Paulo in brazil. The subjects were divided into four groups. The first group was just given the placebo supplementation, second group was provided with creatine supplementation and in the remaining two groups resistance training was incorporated with placebo supplementation in one and creatine supplementation in other group. The subjects were evaluated prior to the intervention and post intervention to look at the results. The primary outcome measured was muscle strength whereas the secondary outcome measured was physical function test , appendicular lean mass and biochemical bone markers.