A Case Study on Resistance Training

A Case Study on Resistance Training

Question One

The interface between the nervous system and the musculoskeletal system that leads to body movement is the coordination of the muscular system and the nervous system. There are over two hundred bones in the human’s musculoskeletal systems that are attached to muscles. During resistance training, body movement is caused by the contractile tissues. Sensory electric signals are organized in the peripheral nerves, sent to the brain, then to the particular muscle causing contraction. Proteins in the muscles the actins and myosin slide over each other to cause contraction of the muscle fibers. The bone movement is guided by complementary pair muscles such as biceps and triceps.

Resistance training leads to the contraction of the muscular system. Muscles contraction pulls on both the origin and insertion in bones causing movement in the joints. During the reverse motion, the corresponding muscle contracts to allow joint movement. Contractions in the muscle are either concentric or eccentric. During a concentric contraction, muscles shorten while in eccentric contraction muscles shorten and lengthen. Eccentric contractions generate more force and strength compared to concentric contractions. Also, due to the higher force generated, eccentric contraction leads to sore muscles.

An increase in the volume of resistance training improves the ability of the nervous system to drive muscles. Increased repetitions and weights enhance how the electric signals are transmitted from the brain to the muscles. During training exercises, the release of chemical neurotransmitters at the neuromuscular junction is increased, causing increases coordination (Carroll et al., 2001). This explains the reason muscle strength increase without an increase in the size of the muscle structure.

Fatigue is a limitation of strength. The muscle is unable to maintain its functions temporarily. Increased resistance training causes excess accumulation of hydrogen ions. Also, intercellular lactate causes impaired performance of contractile proteins. Fatigue is also caused by sarcoplasmic reticulum and reduced reactive oxygen species.

The size principle dictates the order in which the motor units are recruited during training. The order of recruitment is from the smallest to the largest, depending on the intensity of the exercise. During training, the motor units become more adaptive to the training pattern. The efficiency of the neural system increases, allowing better coordination with other body systems. Eventually, the muscle system becomes more adaptive, allowing an increase in strength.

Question two

The two forces involved in push-ups are the gravitational force and the constructional force. Gravitational force is the force pulling one towards the center of the earth. The effect is dependent on her weight. The constructional effect is the force due to the movement of joints and muscles. The movement of the body causes contraction and relaxation of the body muscles.

During pull-ups, the target agonist muscle is the latissimus dorsi. This muscle is found at the back, and it is the broadest muscle of the upper body (Hewit, 2018). It helps to pull you up during exercise as the primary mover. However, there are other muscles targeted during this exercise; teres major works hand in hand with the lat’s to adduct the shoulders. As the arms extend at the shoulder and swing down from the front, rear deltoid muscles together with pectoralis major ate used to maintain that posture. Also, biceps branchia and brachialis are used in flexing the arms and keeping them stable. During the positive phase, the shoulder joints are adducted. There is the movement of the upper arms from the side plane in the overhead position and moves to the side of the body. The action involved the lower pectoralis major, the teres major, and the lattisssimus dorsi. The scapula experiences a downward location, and the muscle involved is the pectoralis minor and rhomboid.

An external moment arm is a moment caused by external forces acting to the arm. The role of the moment arm is to determine the quality of the torque. Internal forces causing moment across the joint axis on the arm are inner moment arm. The distance between the joint axis and the line the acting force is known as the moment arm. The forces from the joints are most significant when the distance between the joint and the load is the longest. Internal forces arm is the muscular forces caused by the muscles. Muscles are attached to bones through tendon entering larger forces in the body.

When a human body interacts with an external object like a dumbbell, torque is produced. The torque is dependent on the force acting on the joints during exercise (Hewit, 2018). To minimize torque, use the correct setup to help reduce the use of dangerous mechanics. Second, it is essential to use excellent mechanics concerning posture required by the exercise. Moreover, it is necessary to control the moment and speed during training. A counting system will help one keep the pace and momentum in check. Finally, shortening the moment arm will help reduce torque. This is done through reduced arm extension during exercise.

Question Three

If Felicia takes her training as described in the study question, there will be an acute increase in the concentration and the release of both protein and steroid hormones. An increase in growth hormones insulin and testosterone will help facilitate growth and recovery of muscle tissues. However, during resistance training, muscle degrading hormones are acutely elevated. Moderate to high-intensity training will release significant amounts of epinephrine, which has a long-term negative effect. One is, therefore, advised to increase the consumption of protein and carbohydrates before and after the resistance training. During the resistance, training muscles experience several acute effects. One such result is the depletion of metabolic substrates such as glycogen and creating phosphate. These two acts, like the fuel sources during training; hence, their consumption leads to decreases in power muscle. Also, resistance training causes intramuscular elevation of hydrogen. An increase in hydrogen ions in the muscles causes a reduction in intramuscular pH (Kraemer & Ratamess, 2005).

A chronic adaptation of muscles is an increase in the cross-sectional area of the flesh; this is also known as hypertrophy. It occurs in two types a slow switch and fast switch muscle response. The level of change in hypertrophy is dependent on the intensity and volume of the exercise. The effect is the increase in the strength of the muscles.

Overload of muscles causes a change in protein synthesis due to the distribution of extracellular matrix and myofibers. The difference in protein synthesis is through changes in binding of the ribosome to mRNA or by modifying the methylguanosine. Induced protein synthesis is essential to the growth process. Also, volumes of resistance training may contribute to muscle hypertrophy. This occurs due to induced calcium ions permeability in the fiber membrane leading to increased protein synthesis in the skeletal muscles (Kraemer & Ratamess, 2005). The rate of metabolic stress is increased through intense training. Resistance training leads to muscle ischemia leading to metabolic adaptation in muscles.

Adaptive training leads to an increase in the blood concentration of anabolic hormones. The membrane sensitivity and receptors to anabolic factors are stimulated by the forces produced in activated fibers during resistance training. This anabolic factor includes growth hormones that lead to muscle growth and changes in strength. The endocrine system then tends to increase the concentration of the hormone in the blood.

The mTORC1 positively regulates cell growth by promoting anabolic processes. Also, it inhibits catabolic processes. To perform these tasks, it integrates four signals, including energy status, growth factors, amino acids, and oxygen. Activation of Ras and insulin signaling pathway stimulates mTORC1 via growth factors. AMPK, which is an activated protein, signal the energy status of the cell to mTORC1. An amino acid is a primary signal that positively regulates mTORC1. The levels of energy in the cell affect mTORC1 in several ways. Reduction in ATP levels activates AMPK, which then promotes the activation of TSC1 and two, thus inhibiting mTORC1 (Laplante & Sabatini, 2009). An increase in energy levels will have the opposite effects. Endocrine adaptation leads to decreased change or no change in heart rate and blood pressure while training.

The mTOR plays a role during mechanical uploading in the protein synthesis, a muscle mass. The decrease in the concentration of mTOR causes a fall in protein synthesis and the weight of the muscle. Consequently, during denervation, the muscles experience increased protein synthesis. Moreover, it increases the degradation of proteins through negative feedbacks of the anti-catabolic pathway. mTOR signals such as amino acid have an enduring effect on the MPS and cross-sectional area. A sufficient amount of amino acids have a significant impact on muscle adaptation. Compared to carbohydrates, amino acids that are rich in protein increase the cross-sectional area. Intake of amino acids tends to increase muscle thickness in middle-aged women.

On the other hand, resistance training causes an increase in the cross-sectional size of the muscle fiber, which is a chronic adaptation. There are two types of hypertrophy, namely slow-switch and fast-switch muscle fibers. The level of hypertrophy is d0ependent on the volume and intensity of the resistance exercise. Hypertrophy leads to an increase in muscle strength and power.

Concurrent resistance training and aerobic running effect on anaerobic hypertrophy are dependent on the volume and intensity of the practice (Lundberg et al., 2013). A concurrent training combining low volume resistance training and high-intensity aerobic running leads to lower activation of AMPK. This leads to inferior anaerobic hypertrophy. Also, the order in which the training is done affects muscle hypertrophy—taking aerobic exercise before leads to an inhibition of performance during resistance training. Other studies suggest the aerobic-resistance order will increase adaption in resistance training all the studies are inconclusive in this regard. However, a recent peer review study indicated that concurrent training negatively affects resistance training adaptation. This is because the high intensity and volume training lead to inhibition pod AKT-mTOR pathway activation.

References

Carroll, T. J., Riek, S., & Carson, R. G. (2001). Neural adaptations to resistance training. Sports medicine, 31(12), 829-840.

Hewit, J. (2018). A Comparison of Muscle Activation during the Pull-up and Three Alternative Pulling Exercises. Journal Of Physical Fitness, Medicine & Treatment In Sports, 5(4). https://doi.org/10.19080/jpfmts.2018.05.555669

Kraemer, W., & Ratamess, N. (2005). Hormonal Responses and Adaptations to Resistance Exercise and Training. Sports Medicine, 35(4), 339-361. https://doi.org/10.2165/00007256-200535040-00004

Laplante, M., & Sabatini, D. (2009). mTOR signaling at a glance. Journal Of Cell Science, 122(20), 3589-3594. https://doi.org/10.1242/jcs.051011

Lundberg, T. R., Fernandez-Gonzalo, R., Gustafsson, T., & Tesch, P. A. (2013). Aerobic exercise does not compromise muscle hypertrophy response to short-term resistance training. Journal of applied physiology, 114(1), 81-89.

Petré, H., Löfving, P., & Psilander, N. (2018). The effect of two different concurrent training programs on strength and power gains in highly-trained individuals. Journal of sports science & medicine, 17(2), 167.

Zając, A., Chalimoniuk, M., Gołaś, A., Lngfort, J., & Maszczyk, A. (2015). Central and peripheral fatigue during resistance exercise–A critical review. Journal of human kinetics, 49(1), 159-169.