A2 PE - Chapter 2

Why Do We Warm Up?

·         Physiological and physical benefits

·         Reduce risk of injury

·         Increase heart rate to get blood moving to working muscles

·         Improves muscle elasticity

Stage 1: Initial Preparation, Gross Motor Skills and Pulse Raiser (Purpose is to introduce stress to the body in a gradual, controlled manner Raises temperature of the body’s core and specific muscles)

Stage 2: Injury Prevention (Some mobility exercises can now be performed, Most common types of activity in this stage are stretches, Static stretching lacks specificity)

Stage 3: Skill Practice (Should involve a skill related component, Neuromuscular mechanisms related to the activity are worked (e.g. tennis serve)

Stage 4: Sport Specific (Practising specific skills and exertions similar to how they will be experienced in a game situation (e.g. rugby attack vs defence drills)

Static - Lack of movement, muscle taken to its current elastic limit and held in position for up to 30 seconds, Very safe as you maintain control of movement

Active Static - This is when you assume a position and then hold it, with no assistance

Passive Static - Assume a position and hold it with some other part of your body, or with the assistance of a partner or some other apparatus

Dynamic - Involves moving parts of your body and gradually increasing reach, speed of movement, or both, It consists of controlled/slow leg and arm swings that take you gently to the limits of your ROM, This type of stretching improves dynamic flexibility

Ballistic - Uses the momentum of a moving body or a limb in an attempt to force it beyond its normal ROM, This is stretching by bouncing into or out of a stretched position using the stretched muscles as a spring that pulls you out of the stretched position.

PNF - a muscle is passively stretched, then contracts isometrically against resistance while in the stretched position and then is passively stretched again

“An organised approach to training that involves progressive cycling of various aspects of a training programme over a specific period”

Macrocycle – The entire period of the training programme

Mesocycle – Macrocycle is split into blocks called mesocycles

Microcycle – individual sessions which are in a mesocycle.

The athlete will set clear and specific objectives in the MACROCYCLE

Objectives in a MESOCYCLE will be different but will fit into the overall macrocycle,

The athlete will then also have objectives for each MICROCYCLE, which will fit into the mesocycle objectives that they are training in

·         A chemical compound that is the energy source for all muscular efforts

·         Sources of ATP are: Carbohydrates, Fats and Proteins

·         Created in the Mitochondria

      ATP ----> ADP + P + Energy

Carbohydrates

·         When digested, they are broken down to glucose and stored as glycogen in the muscles and liver

·         Glycogen can provide the energy for ATP production under both anaerobic and aerobic conditions

Fat

·         Major source of energy for long term activity

·         Is used to meet sub-maximal energy demands

·         During rest conditions, fat produces the majority of the required ATP

Protein

·         Only minimally contributes to ATP production,  Is only used in severe circumstances (marathon or starvation) when the body has severely depleted

Energy From ATP

·         ATP is stored in limited quantities in the muscle, so each muscle fibre must be able to create its own

·         For release of energy, one phosphate molecule breaks off, releasing energy and creating ADP

·         As long as there are sufficient energy substrate, this process can be reversed with the use of food fuels and ATP is rebuilt with the addition of another phosphate

Alactic (ATP-PC) – Anaerobic

·         Provides the bulk of ATP during explosive efforts

·         May be one off (jumping) or ongoing (100m sprint)

·         Lasts for about 10 seconds of maximal efforts

Lactic Acid – Anaerobic

·         Provides energy in high intensity, sub maximal efforts

·         Muscle stores of glycogen are broken down to resynthesize ADP, Lasts from around 10 seconds up to 1 minute of exercise

Aerobic

·         Provides the bulk of energy for sub maximal efforts and recovery, contributes to all activities from 1 minute onwards, Fat becomes a significant contributor to ATP production, can operate for an unlimited work period

Recovery – Fast Component

·         Aim of the recovery process is to replace ATP and glycogen stores as soon as possible

·         The fast component lasts up to 4 minutes after exercise

Recovery – Slow Component

·         Heat dissipation, energy replenishment, rehydration and removal of waste products are the main aims

·         This can take up to 48 hours after a performance

Muscle Fatigue

·         A reduction of muscular performance, An inability to maintain expected power output caused by: Depletion of energy stores (depletion of ATP) and accumulation of metabolites (co2, Lactic) – stops muscle contractions happening, Other causes include anticipated fatigue (CNS perceiving fatigue) and body fluid balance (keeping hydrated with right amounts of fluids)

Water Loss

·         Loss as little as 2 to 3% of water can reduce performance by up to 10%

·         Isotonic sports drinks including glucose and electrolytes can prevent dehydration

·         Heart rate can increase if fluid isn’t sufficient during prolonged exercise

Restoration of ATP, PC, Glycogen

·         Window of opportunity after exercise to replenish stores of all three, Complex carbohydrates are digested as soon as possible after exercise to aid a quicker recovery in the window of opportunity

Summary

·         The excess O2 consumed following exercise needed to provide the energy needed to resynthesize ATP used and to remove lactic acid created during previous exercise

·         EPOC has two components: Fast (Alactic) and Slow (Lactic)

·         Reduced heart rate

·         Increased onset of sweat production

·         Increased sweat rate

·         Expanded plasma volume

·         Improved control of cardiovascular function

·         Body reduces the amount of sodium chloride (essential electrolytes) lost during sweating. They decrease during days 3-9 of acclimatisation

·         These responses together can significantly reduce central body temperature. Response is maximised 5-8 days after heat acclimatisation. Acclimatisation in hot, humid conditions stimulates a higher sweat rate than in a dry hot environment

Heat Syncope

·         Occurs most commonly during the first 3-5 days of heat exposure

·         This is due to the vascular shunting of blood to the skin in order to cool down, and the consequent reduction in venous return and drop in cardiac output, in turn leading to a drop in blood pressure

Heat Exhaustion

·         The most commonly diagnosed form of heat illness among athletes, despite the fact its symptoms are often vague.

·         Clinical descriptions include headache, dizziness and fatigue among others

·         Defined as the inability to continue exercise in a hot environment

·         Since 1995, 33 NFL players have died from heat stroke, with 3 this year

·         VO2 max is defined as the maximum capacity of an individuals body to take in, transport and utilise oxygen, per minute, per kg of bodyweight

Adaptation To Dry Heat

·         In a drier heat, the body is better able to lose heat through sweating as the atmosphere will absorb the moisture better.

·         The danger then becomes one of dehydration, as the athlete may not realise how much they are sweating as the sweat evaporates quickly from the skin

Heat Cramps

·         Cramps usually occur in the muscles of the legs, arms and abdomen after several hours of strenuous exercise in individuals who have lost a large volume of sweat, have drank a large volume of hypotonic fluid and who have secreted a small volume of urine

·         Sodium depletion probably causes heat cramps

·         Increase in stroke volume (lowers heart rate)

·         Increase in cardiac output

·         Increase in number of capillaries (more blood and oxygen sent to working muscles)

·         Increase in number and density of mitochondria (more ATP production)

·         Reduction in body fat (increase ability to use fat as energy)

·         Increase in lean body mass (better muscle:fat ratio)

·         Increased lactate threshold (utilise, tolerate and transport more lactate)

·         Increased VO2 max (more oxygen intake)

·         Increase in myoglobin (more oxygen can be carried)

·         Increase in end-systolic volume + decrease in end-diastolic volume

·  

Anaerobic training is when you exercise at an intensity that is too high for the body to satisfy aerobically

Both ATP-PC system and Lactic acid system are trained

Anaerobic Threshold – The intensity at which the anaerobic energy systems become the dominant energy providers

Lactate Threshold – the exercise intensity at which lactic acid starts to accumulate in the bloodstream because it is produced more quickly than it can be removed

Untrained athletes will have a low anaerobic/lactate threshold, elite athletes will have a high anaerobic/lactate threshold

Lactic Acid

·         All exercise produces lactic acid, it is broken down and removed by oxygen present

·         Greater intensity = more lactic acid

·         Eventually the body cant remove it and it builds up in the bloodstream

·         4mmol OBLA (Onset of Blood Lactate Accumulation) – anaerobic/lactate threshold

Fuels For Energy

·         Glucose from muscle glycogen stores and PC

·         Instant energy from PC to resynthesize ATP from ADP

·         Limited supply of PC (8-10 seconds)

·         If intensity of activity drops slightly, the body can regenerate ATP through Glycolysis

·         Increase in PC stores (more to resynthesize ATP from ADP)

·         More anaerobic enzymes (to convert lactic acid into pyruvic acid)

·         Greater lactic acid tolerance (body utilises it better, body can buffer it more, increase bodys ability to tolerate more)

·         Increased thickness of Ventricular Myocardium

·         Increased strength of ventricular contractions

·         Decreased end-systolic volume

·         Increased stroke volume

·         Myofibrillar Hypertrophy (more muscular contractions)

·         Increased muscle  mass