Exercise Physiology

Exercise physiologists oversee the analysis, improvement, and maintenance of health and fitness, rehabilitation of heart disease and other chronic diseases and disabilities, and the professional guidance and counsel of athletes and others interested in sports training. In addition, many exercise physiologists study the effect of exercise on pathology, and the mechanisms by which exercise can reduce or reverse disease progression. There is no license to become an exercise physiologist. Therefore, the range of exercise physiology is extensive. An exercise physiologist's area of study may include but is not limited to biochemistry, bioenergetics, cardiopulmonary function, hematology, biomechanics, skeletal muscle physiology, neuroendocrine function, and central and peripheral nervous system function. Exercise physiologists can be basic scientists, clinical researchers  and even sports trainers.

Key Terms –

VO2 max: (also called maximal oxygen consumption, maximal oxygen uptake, peak oxygen uptake or aerobic capacity) it is the maximum capacity of an individual's body to transport and use oxygen during incremental exercise, which reflects the physical fitness of the individual.

Lactic acid: it is a chemical compound that plays a role in several biochemical processes. Specifically regarding to exercise, when the rate of demand for energy is high, lactic acid is produced faster than the ability of the tissues to remove it, so lactate concentration begins to rise. This is a beneficial process, since the regeneration of NAD+ ensures that energy production is maintained and exercise can continue.

Aerobic respiration: requires oxygen in order to generate energy. Although carbohydrates, fats, and proteins can all be processed and consumed as reactant, it is the preferred method of pyruvate breakdown in glycolysis and requires that pyruvate enter the mitochondrion in order to be fully oxidized by the Krebs cycle. The product of this process is energy in the form of ATP (Adenosine triphosphate).

Anaerobic respiration: it is a form of respiration using electron acceptors and instruments other than oxygen. It is respiration without oxygen.

ATP: Adenosine triphosphate is a multifunctional nucleotide used in cells as a coenzyme. ATP transports chemical energy within cells for metabolism. It is produced by photophosphorylation and cellular respiration and used by enzymes and structural proteins in many cellular processes, including cell division.

CP: Phosphocreatine, also known as creatine phosphate, is a phosphorylated creatine molecule that serves as a rapidly moveable reserve of high-energy phosphates in skeletal muscle and brain.

Glycolysis: it is the metabolic pathway that converts glucose into pyruvate. The free energy released in this process is used to form the high-energy compound ATP.

Carbohydrates: an organic compound that consists only of carbon, hydrogen, and oxygen, with a hydrogen to oxygen atom ratio of 2:1 (as in water).

Fats: consist of a wide group of compounds that are generally soluble in organic solvents and largely insoluble in water. Chemically, fats are generally tri-esters of glycerol and fatty acids.

Proteins: they are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form in a biologically efficient way.

Energy Pathways –

1.       ATP-CP splitting for explosive movements and short sprints

2.      Anaerobic glycolysis for longer sprints

3.      Aerobic metabolism for endurance events

Heart Surgeries

Heart Patient X Case Study

Patient: Mr. X

Age: 47

Height: 6’1”

Weight: 235 lbs

History: Mr. X was recently laid off from his stressful job as a real estate agent due to the failing economy. Now his stress level has skyrocketed as he is searching for a job. (He has two teenage children that he must send to college in the next few years and without a job, he won’t have the money to support them.) With no income, he can only afford to eat highly processed fast foods that contain little nourishment. Mr. X was feeling tightness, aching and discomfort in his chest. He initially thought it was heartburn or indigestion and took an over-the-counter drug, Pepto Bismol in hopes that it would go away. His chest pain, called angina, has since worsened and now he is also feeling shortness of breath.

Family History: His mother’s side of the family has a history of obesity and heart attacks.

Tests: Mr. X’s physical examination depicted that he has high blood pressure (hypertension). The EKG test checked for problems with the electrical activity of Mr. X’s heart. These showed that Mr. X had an abnormal heart beat and that there was an underlying problem. An electron-beam computed tomography (EBCT) was performed on Mr. X, which illustrated how severely the calcium build-up in the lining of his arteries had become. The final test, an angiocardiography, was able to show us a radiographic examination of the heart chambers and thoracic vessels by the injection of radiopaque dye. This heart x-ray determined the extent of Mr. X’s coronary artery disease.

Pulmonary Arterial Hypertension and calcium build up in Mr. X’s heart

Diagnosis: Mr. X has coronary heart disease, which is a disease that develops when a combination of fatty material, calcium and scar tissue (plaque) builds up in the arteries that supply the heart with blood. The build up narrows the arteries so that the heart does not get enough blood, causing chest pain (angina) and ultimately if left untreated, a heart attack (myocardial infarction) or a fatal rhythmic disturbance (cardiac arrest).

Treatment: Mr. X should get a coronary bypass to relieve his pain.  This is an invasive surgical procedure performed to improve blood supply to the heart by creating new routes for blood flow since the old routes have been obstructed by plaque build up. The surgery requires the removal of a healthy blood vessel from another part of the body, such as the arm or leg, so that it can be grafted onto the heart to circumvent the blocked artery. Mr. X should also make lifestyle changes, such as reducing his stress level and eating healthier so that he can reduce the risk of worsening his disease. If he does not make these lifestyle changes, Mr. X will likely end up having a heart attack and would need a heart transplant. This would entail removing the diseased heart and replacing it with a new, healthy heart. Transplants can be risky and are not always successful. It would be best if Mr. X made lifestyle changes now and did not go down the path of heart failure before it is too late.

Artificial Organs

The organ in the image above is a bio-artificial ear. It was grown from the patient’s own stem cells.

Scientists are calling regenerative medicine the "Holy Grail" of stem-cell research because tissue regeneration could make invasive surgeries a thing of the past. For instance, a patient with a bladder disease can be grown a new bladder. The whole process takes six to eight weeks, but the results are life-changing and well worth the wait. In order for cell regeneration to work, you must take healthy cells from a patient's diseased bladder, cause them to multiply greatly in petri dishes, then apply them to a balloon-shaped scaffold (structure) made partly of collagen, which is the protein found in cartilage. Muscle cells are put on the outside, while urothelial cells (which line the urinary tract) are put on the inside. The next step is that the structure must then be incubated at body temperature until the cells form functioning tissue.

Artificial Organs
Pros:	Cons:
Engineering tissues can potentially help people conquer illnesses and diseases	If the body tissue used to reconstruct particular tissue had latent or hidden diseases or illnesses, they could carry over to the new tissue
Has the capability of prolonging life/makes the general quality of life better	Many people have ethical issues with using stem cells
Will make organ transplant lists and waiting for donors unnecessary
Stem cells are readily available