Acute responses to exercise Flashcards
Systolic & Diastolic Blood Pressure
Systolic blood pressure is the maximum blood pressure during contraction of the ventricles whereas diastolic blood pressure is the minimum pressure recorded just before the next contraction. The blood pressure is usually written as the systolic pressure over the diastolic pressure
Blood flow distribution at rest and during exercise
Blood flow distribution at rest is 20% to muscles and 80% to the organs, but during exercise, it is 80% to the muscles and 20% to the organs
Arterio-venous oxygen difference (a-V02 diff)
Arterio-venous oxygen difference or a-V02 diff measures the amount of oxygen taken from the blood by the issues. So the greater the amount of oxygen extracted by the tissues, the greater the arteriovenous oxygen difference. Physical exercise leads to an increase in the arteriovenous oxygen difference in all individuals. As exercise intensity increases, the muscles increase the amount of oxygen they extract from the blood, resulting in further increases in a-V02 diff. So at rest, a-V02 diff is low
Ventilation (V), tidal volume (TV) and Respiratory rate (RR)
Respiratory rate + tidal volume = ventilation
RR - The number of breaths per minute.
TV - The amount of air inhaled and exhaled per breath.
VE - Amount of air moved into and out of the respiratory tract each minute
Stroke volume (SV), Cardiac Output (Q) and Heart Rate (HR)
Heart rate + stroke volume = cardiac output
HR - Number of times the heart beats in one minute
SV - How much blood is squeezed out of the heart into the aorta each time it beats
Q - The amount of blood pumped out of the heart per minute
Blood lactate, Hydrodren Ions (H+) and metabolites (metabolic Byproducts)
Blood lactate and hydrogen ions (the process of glycolysis) - glycogen breaks down to glucose, then breaks down into pyuvic acid, then breaks down into lactic acid then lactate and/or hydrogen ions
so blood lactate is a metabolite or metabolic byproduct of anaerobic metabolism primarily produced in muscles during intense exercise or when oxygen supply is limited. It can serve as an energy source or be converted back to glucose in the liver through the Cori cycle. Elevated blood lactate levels can indicate increased anaerobic metabolism and may be associated with fatigue or muscle soreness
Acute muscular responses to exercise and how they contribute to increased/decreased performance - Cardiovascular
Heart rate - increases, 60-80BPM at resting, moderate 120-150BPM & intense 180-200BPM during exercise. HR increases to meet the demands of exercise and deliver more O2 to working muscles (physiology). Allowing us to work at a higher aerobic intensity (performance)
Redistribution of blood flow - increases, muscles 20% and organs 80% during rest, muscles 80% and organs 20% during exercise, vasoconstriction occurs in arterioles supplying oxygen to the inactive areas and vasodilation occurs in the arterioles supplying oxygen to the working muscles (physiology). So the working muscles can receive more oxygen therefore increasing energy exerted by the body to better performance (performance)
Plasma volume - decreases, higher during rest, and lower during exercise, due to sweating and fluid loss during exercise, the plasma (fluid component of the blood) will decrease (physiology) and the athlete will experience fatigue (performance)
Acute muscular responses to exercise and how they contribute to increased/decreased performance - Respiratory
Respiratory rate - increases, 12-16BPM during rest, moderate 20-30 BPM & intense 40-50BPM during exercise, BR increases to meet the energy demands of exercise and deliver more O2 to working muscles. (physiology) Allowing us to work at a higher aerobic intensity
(performance)
Tidal volume - increases, 500ml/breath during rest, moderate 2.5L/breath & intense 3.0L/breath during exercise, TV increases to allow greater volumes of blood/O2 to be taken in per breath (physiology) Allowing us to work at a higher aerobic intensity (performance)
Ventilation - increases, 6L/min during rest, moderate 50-75L/min & intense 120L-150L/min during exercise, an increased rate and volume of our respiratory parameters leads to more O2-rich blood being distributed to the heart and through to the working muscles per minute. (physiology) Allowing us to work at a higher aerobic intensity (performance)
Acute muscular responses to exercise and how they contribute to increased/decreased performance - Muscular
Motor unit recruitment - increases, N/A at resting, N/A during exercise, by electrical impulse signals that are sent from the central nervous system to the motor neuron. This enables the correct number of muscle fibres to be recruited dependent on the intensity of activity (physiology). The higher the intensity the greater the motor unit recruitment (performance)
Enzyme activity, Increase, N/A at rest and during exercise. Enzyme activity speeds up chemical reactions, so the increased actions of enzymes such as Phosphofructokinase (PFK) will allow greater ATP production and resynthesis (physiology). We can therefore produce more energy at any given intensity (performance).
Energy substrates (FUEL) - decreases, triglycerides 1-2 days - glycogen 2 hrs - creatine phosphate 10secs during rest, the intensity of exercise will dictate which energy substrate will be contributing the most during exercise, Once ATP stores are depleted, PC, muscle glycogen and muscle triglycerides are all used to resynthesise ATP and so they are metabolized to create energy. All three energy systems work together to resynthesize ATP, so intensity will dictate which one we predominantly use, however we always use a mixture of all three fuels at any one time. (physiology) The higher the intensity and the longer the duration (I.D.) the greater amount of fuel we use (performance).
Vasoconstriction and Vasodilation
Vasoconstriction is the narrowing of blood vessels, and vasodilation is the widening of blood vessels
Normal resting HR values and how Aerobic fitness affects HR recovery
Resting HR values - 60-80BPM
Aerobic fitness affects HR recovery by improving our cardiac efficiency which means higher levels of aerobic fitness levels tend to have lower resting heart rates and means we can recover more quickly after exercise.
Improving our stroke volume which means having an higher aerobic fitness also mean the stroke volume is higher so more blood and O2 to getting delivered.
Decreased lactate accumulation which means athletes with higher aerobic fitness levels tend to produce less lactate during exercise because of improved metabolism and oxygen use.
This all means the an athletes heart rate will recovery and become steady quicker
Steady-state in relation to HR & RR and Lactate
Heart rate remains constant over time under stable physiological conditions
The respiratory rate remains constant over time under stable physiological conditions
Lactate levels stabilise under consistent exercise intensity in metabolic equilibrium
Calculating max HR
220 - your age
Relationship between HR and exercise intensity
As the exercise intensity increases, our heart rate also increases to keep up or equal the oxygen demand our body requires
Energy substrates within the muscles
Energy Substrates are another way of saying muscle fuels. This is the fuel we use to generate muscle contraction in order to move/run etc. The major fuel we need to know for now is Glycogen. In relation to glycogen, just know that it is the fuel we use to create energy and the byproduct of breaking it down is lactate. So, once we use glycogen to create energy and initiate muscle contraction we end up with lactate
Oxygen Deficit
every time we have an increase in intensity during the activity we experience an oxygen deficit, HR and BR need to increase as much as 2 or 3 fold. The greatest deficit occurs in the first minute of the activity. anaerobic pathways control exercise O2 deficit because of the increased amount of time it takes the aerobic energy system to charge and become the major contributor fully. Once the main contributor is an activity it remains so throughout the activity but increased anaerobic contractions mean we will still experience a 02 deficit. To decrease aerobic lag, we experience ‘anticipatory rise” which means our body is preparing the respiratory, cardiovascular and muscular systems for activity
deficit can occur whenever there is a change in intensity which may include simply working harder (increasing running speed), weather conditions (running to a headwind), or any geographical change (running up a hill or on sand)
Steady State
Steady-state is the period during exercise where oxygen supply is equal to oxygen demand
EPOC - Physiological changes
excess post-oxygen consumption - simply be referred to as the amount of oxygen consumed post-activity above that of resting levels. During EPOC, there are several things the body is trying to achieve: resynthesizing muscle fuels (CP, glycogen and triglycerides), restoring muscle electrolyte and nutrient balance and metabolising byproducts like hydrogen irons and lactate
Best EPOC recovery is an activity recovery because it will extend EPOC to allow greater oxidation of H+ ions and refuelling
If your exercise is very intense and of a long duration, you will experience a longer EPOC
VO2 Maximum
The maximum amount of oxygen the body can UPTAKE, DISTRIBUTE & UTILISE per minute.
UPTAKE - the body will respond by increasing respiratory acute responses such as breathing rate to increase O2 uptake
DISTRIBUTE - the body will respond to my increasing cardiovascular acute response such as heart rate to increase O2 distribution
UTILISE - the body will respond by increasing muscular acute responses such as AVO2diff to increase O2 utilization
A person’s VO2 max is a great indicator of aerobic fitness. Endurance athletes tend to have higher VO2 max readings, which means they are better at getting oxygen into the system and utilizing it to create energy
High VO2, high fitness, low VO2, low fitness
High VO2, lower resting heart rate, low VO2, higher resting heart rate
