Physiology for Coaches L2CCS&C

Skeleton

Skeletal Functions Support Protection Articulation through muscle attachment Be aware of differences between adults and children

Major Muscles

Muscle Action Muscle origin; where muscle attaches to bone via connective tissue (tendon) nearest centre of body Muscle insertion; where muscle attaches to bone via connective tissue (tendon) away from centre of body Agonist; prime mover of the movement action Antagonist; opposite of agonist, can slow down or stop the movement Synergist; assists n the movement or supports the body during the movement Give examples

Muscle Action

Circulatory system

Composition of the blood Plasma Red blood cells White blood cells Platelets

Functions of the blood Transport of oxygen Transport of energy in form of dissolved food molecules Transport of hormones Removal of carbon dioxide Removal of other waste products

Structure of cardiovascular system Heart –Right atrium –Right ventricle –Left atrium –Left ventricle Arteries Veins Capillaries Pathway RA>RV>Lungs>LA>LV>body>RA

Structure of the heart

The heart is a dual pump, circulating blood through two separate closed systems. Oxygen- carrying blood leaves the left ventricle through the aorta. It circulates through the body and returns, deoxygenated, to the right auricle via the superior and inferior vena cava. The right ventricle pumps this blood through the pulmonary artery to the lungs, where it exchanges carbon dioxide for oxygen. Oxygenated blood then returns to the left auricle of the heart, ready for arterial circulation, through the pulmonary veins.

Heart rate x stroke volume =cardiac output Blood pressure Systolic: pressure against the arterial walls during ventricular contraction ( x HR = heart work) Diastolic: During ventricular relaxation is the ease with which blood flows from the arterioles into the capillaries

Mechanism of breathing

The diaphragm contracts and moves downward, the pectoralis minor and intercostal muscles pull the rib cage outward. The chest cavity expands, and air rushes into the lungs through the trachea to fill the resulting vacuum. When the diaphragm relaxes to its normal, upwardly curving position, the lungs contract, and air is forced out.

Acute responses to exercise Aerobic –Increase in systolic pressure –Reduction in peripheral resistance Strength training -Increase in systolic pressure -Short term increase in diastolic pressure

Cardiovascular adaptations to training (primarily aerobic) Increased ventricular volume Increased stroke volume Decreased resting and sub maximal heart rates Increased muscle capilliarisation Increased plasma volume Reduction in resting blood pressure

More adaptations to training Increased maximal exercise ventilation Increased maximal oxygen consumption (VO 2 Max) Increased tidal volume ? Increased oxygen extraction Onset of OBLA shifted Increased vital capacity Decreased resting breathing rate Increased maximal breathing rate

Biochemical adaptations to aerobic training Increased myoglobin content (an intra cellular oxygen transporting protein) Increase in number and size of mitochondria Increase in activity of enzymes involved in Krebs’ Cycle and electron transport chain Increase in muscular glycogen stores Increased ability to oxidise fat

Biochemical daptations to anaerobic training Increased capacity of ATP-PC and glycolytic systems Increased muscular stores of ATP and activities of enzymes related to glycolysis and ATP/PC systems

Age and Gender Differences Gender differences: on average age for age women have aerobic power values that range from 73% to 85% of the values of men Women have lower Hb values, smaller hearts and blood volumes Physiological changes as children mature: Strength Power Endurance Reduction with aging of: Maximal oxygen uptake Maximum heart rate Strength performance Peak power Lean muscle tissue, especially fast twitch RPE changes

Energy sources: Fats (primary role) Carbohydrates (primary role) Proteins (secondary role) Carbohydrates are broken down into simple sugars such as glucose Fats are broken down into free fatty acids and acetyl co enzyme A which can enter Krebs Cycle Proteins can be broken down into amino acids which can be converted to glucose (gluconeogenesis), pyuvate and various Krebs cycle intermediates.

Energy Systems Energy is required to do physical work. Energy for the muscles to work is provided by a substance called ATP (adenosine triphosphate). Bioenergetics is the flow of energy within a biological system

Three energy systems provide ATP: Phoshagen system Glycolytic system Oxidative system

Phoshagen system: Provides energy at the start of exercise, in sporting terms is primarily used in short high intensity activities such as weight lifting and sprinting. In this system two reactions occur –ATP > ADP + P + energy –ADP + creatine phosphate > ATP + creatine

Oxidative system: With sufficient oxygen present in the muscles (i.e. when they are working at a lower intensity) the pyruvate from glycolysis enters Krebs cycle. See diagrams Substances produced during Krebs cycle enter the electron transport chain where further ATP is produced See diagrams Total yield of ATP from Oxidative (aerobic) system is 36 molecules per molecule of glucose. Energy is measured in Kilojoules. (USA still use kilocalories)

Cellular Respiration: Simple overview

Glycolysis: Net Energy Gain 2ATP

Citric Acid/TCA/Kreb’s Cycle:

NADH & FADH from glycolysis & Kreb’s Cycle enter Electron Transport Chain

Electron Transport Chain

Glycolytic system: Breakdown of glucose to produce 2 molecules of ATP With insufficient oxygen present pyruvate is converted to lactate in so called “fast glycolysis”. This produces ATP at a fast rate but only for a short period of time as the lactic acid built up causes muscle fatigue

Lactate formation during “fast glycolysis”

Nutritional Awareness Food groups; meat; vegetables; fruit; dairy; breads and cereals; fats and oils Nutrients: carbohydrates; fat; protein; vitamins; minerals; water Healthy eating: sources of nutrients from food groups; energy and nutrients; government and advisory body guidelines; eating patterns and habits Nutrition and exercise: fuels for exercise – carbohydrates, fats; fluids; sports drinks; dehydration; re-hydration Food labels: nutritional information; calculating nutrients Ergogenic aids and performance: research in ergogenic aids, categories of ergogenic aids – pharmacological agents, hormonal agents, physiological agents The reasons for supplement use by players/athletes

Food Pyramid

Physiological differences between adults and children The biochemical pathways of anaerobic respiration are not fully developed in children The circulatory system is not fully developed in children Sensitive periods in growth regarding aerobic development Girls enter the sensitive phase before boys