Blood Supply to the Muscles

The Physiology of Fitness Assignment 1 Helpsheet Step 1 You need to introduce your assignment, here I would define two key terms for the entire of this assignment these are chronic and acute. Example Answer There are many changes to the body during exercise; these can be classified as acute and chronic. Acute meaning they are short term and happen almost instantly with the onset of exercise. The other chronic is long term and allows the body to adapt its capabilities so therefore it can meet new demands in the future.

Examples of these will be discussed in time through each one of these bodily systems: musculoskeletal, energy, respiratory and cardiovascular system. Step 2 At this stage of the assignment you need to look at the first body system of musculoskeletal. Here you need to identify all of the acute changes that take place within this system and then relate this to a sporting example. Some of the changes you need to discuss are: Increased blood supply, increase in muscle pliability, increased range of movement and muscle fibre micro tears.

Example Answer Increases the range of movement – when we start to exercise the movements of our joints means that synovial fluid starts to secrete within the joints. The fluid becomes less viscous and therefore the range of movement within the joint increases. An example of this in sport is the need for a warm up for a butterfly swimmer. So they can get the full range of movement at the shoulder joint that area has to be warmed up prior to the race. Step 3

Keeping the musculoskeletal changes in mind you now need to discuss the chronic responses, these are: hypertrophy, increase in tendon strength, increase in myoglobin stores, increase in muscle strength, increase in tolerance to lactic acid, increase in bone calcium stores, increased stretch of ligaments, increased thickness of hyaline cartilage and increased production of synovial fluid. Example Answer Increased production of synovial fluid – as mentioned previously the movements stimulate the secretion of synovial fluid.

With regular exercise this fluid on initial release is less viscous and the range of movement at the joint increases as connective tissue improves its flexibility. An example in sport is a high jumper. Over a prolonged period of training their knee joint in particular will take a lot of strain, this repetitive strain will allow for the knee joint to increase synovial fluid production as the jump can not e performed without the knee joint. Step 4 You now need a new side heading of energy systems and at this stage we will talk about the acute responses of the energy system.

You need to discuss each of the three energy systems and how they initially respond to exercise. Example Answer Creatine Phosphate System – When exercise intensity is high, or energy needs are immediate, Creatine phosphate stored in the muscle is broken down to provide energy to make ATP. When the high energy bond in Phosphocreatine is broken, the energy it releases is used to resynthesise ATP. Explosive work can be achieved but for only short periods at maximum intensity.

An example of this would be triple jump, if the athlete needs immediate energy this system is used, as the sport will last up to 10 seconds on completion of each jump it can not wait for energy from the Lactic Acid system. Step 5 In this section you need to discuss the chronic changes which apply to the energy system, you need to discuss in particular the aerobic system but also make specific reference to an increase in aerobic and anaerobic enzymes and increased use of fats as an energy source. Example Answer

Increased use of fats as an energy source – Fat oxidation increases if exercise extends to long periods, as glycogen levels deplete. This is particularly prevalent to marathon runners. These athletes will burn of the glycogen in the carbohydrates digested and will need another source of energy to refer to this is where fats are then used. Step 6 Under the side heading of respiratory you need to discuss the acute changes in this system. You will need to mention the following changes: increased breathing rate and increased tidal volume as well as many others.

Example Answer Increased breathing rate – due to the fact the working muscles require energy during exercise the brain sends signals to increase the breathing rate. This increase in breathing rate allows for more oxygen to be taken in and then delivered to the working muscles. It also allows for the waste products to be exhaled much quicker. An example of this is a footballer will gradually increase their breathing rate the longer the game lasts and the more that the muscles demand oxygen to fulfil physical movements. Step 7

You now need to discuss the chronic changes to the respiratory system again relating them to sport to show understanding; you need to include the following: increased vital capacity, increase in minute ventilation, increased strength of respiratory muscles and increase in oxygen diffusion rate. Example Answer Increased strength of respiratory muscles – like any muscle the more that it is worked the greater it’s strength, therefore the same can be said of the intercostals muscles of the chest cavity, due to the increased work load in breathing they become more efficient allow for greater expansion of the chest.

An example of this would be a tour de France cyclist. Due to the intense nature of the event there chest capacity will have to increase to meet the constant demands. Step 8 Under the side heading of cardiovascular system you will now need to discuss the acute changes to this system giving sporting examples. The following changes will need to be discussed: Heart rate anticipatory response, activity response, increased blood pressure, vasodilation and vasoconstriction. Example Answer

Vasoconstriction – this is where the blood vessels decrease in diameter to restrict the flow of blood to an area of the body which does not need the blood supplies as much as another area. An example of this is a boxer, here due to the repetitive punching from the fighter the arms and upper body needs the blood to allow for regular movement, the legs receive less. This is why when a fighter is knocked down commentators sometimes say “his legs have gone” this is because of a lack of oxygen as it has all gone to the upper body and brain. Step 9 Finally you need to talk about the chronic change to the cardiovascular system.

This area is vast and needs a lot of detail. The changes you will need to discuss include: cardiac hypertrophy, increase in stroke volume, cardiac output, resting heart rate, capillarisation, blood volume, blood pressure, recovery time and aerobic fitness. Example Answer Decreased resting heart rate – this is a chronic change because the heart adapts and learns how to cope with the demands of extreme and intense workouts the more you exercise, this therefore means the normal everyday task do not apply as much strain to the body therefore not requiring the heart to increase blood supply to the areas of the body that are working.