Ex Phys Lab Flash Cards
John is 20 years old and has a RHR of 60 BPM. Find THR for 80% MAS effort.
For a 80% MAS effort THR = [(200-60) X 80%] + 60 THR = (140 X 80%) + 60 THR = 112 + 60 THR = 172
Reciprocal Inhibition
-A reflex phenomenon that prevents muscles from working against each other by inhibiting antagonists. -The simultaneous relaxation of one muscle and the contraction of its antagonist to allow movement to take place.
Autogenic Inhibition
-The process by which neural impulses that sense tension are greater than the impulses that cause muscles to contract, providing an inhibitory effect to the muscle spindles. -Reflex inhibition of a motor unit in response to excessive tension in the muscle fibres it supplies. Muscle tension is monitored by the Golgi tendon organs. Autogenic inhibition is a protective mechanism, preventing muscles from exerting more force than the bones and tendons can tolerate
Four Factors that Help Formulate the Interval Training Program
1) Intensity of exercise interval 2) Duration of exercise interval 3) Number of exercises 4) Duration of recovery
RPE difference in Squats vs Overhead Press
2 Reasons: First, when a person performs squats, they are using many different regions of muscle. From the primary engaged muscles (such as the gluteus maximus, quadriceps and hamstrings) to the secondary muscles (erector spinae, transverse abdominus, abductors, adductors, soleus, gastrocnemius) there are many more areas of the body in use when performing a squat vs. an overhead press exercise. Therefore, the RPE will be higher, simply because the person has to use more muscles of the body to generate more force which will cause more peripheral fatigue around the entire body. Also, doing squats causes central fatigue, which is the reduction of neural drive towards working muscles. Therefore, when you do squats, not only do your muscles become tired, you also become mentally tired. Therefore, this combination of physical and mental fatigue causes your RPE to be higher for squats. When you do overhead press, you fatigue due to peripheral fatigue. Unlike squats, which cause your whole body to be tired, overhead press will fatigue the muscles in your arms, but your body as a whole will not feel fatigued. Therefore, the RPE will not be a high for this exercise due to the minimal overall fatigue of your system as compared to when you perform squats.
Why does heart rate decrease with training?
As you train, two primary things happen that increase your stroke volume and therefore allow you to have a decreased heart rate with the same cardiac output. One of the adaptations is that your heart rate simply becomes a stronger muscle. A stronger muscle can contract more forcefully and force out more blood with each contraction. Another adaptation that leads to increased stroke volume is that when you train, the volume of your blood increases. This increase in blood volume actually allows more blood to be returned to the heart. As more blood is returned to the heart, the heart chambers actually stretch before they contract and push out all of the blood.* This leads to an even stronger contraction that again increases stroke volume, and therefore increases cardiac output.
Drift in Heart Rate
Cardiovascular drift is the phenomenon where some cardiovascular responses begin a time dependent change, or "drift" after around 10 minutes of exercise in a warm or neutral environment. It is characterised by decreases in mean arterial pressure and stroke volume and a parallel increase in heart rate. It is influenced by many factors, most notably the ambient temperature, hydration and the amount of muscle tissue activated during exercise, Glycogen depletion also causes a heart rate drift. To promote cooling, blood flow to the skin is increased, resulting in a shift in fluids from blood plasma to the skin tissue. This results in a decrease in pulmonary arterial pressure and reduced stroke volume in the heart. To maintain cardiac output at reduced pressure, the heart rate must be increased.
Steady State Training Definition
Definition: constant submaximal exercise below lactate threshold where oxygen consumption is meeting energy requirements of the activity.
John is 20 years old and has a RHR of 60 BPM. Find THR for 60% MAS effort.
For a 60% MAS effort THR = [(200-60) X 60%] + 60 THR = (140 X60%) + 60 THR = 84 + 60 THR = 144
What is the relationship between heart rate and blood pressure during anaerobic work?
During anaerobic exercise, your heart rate speeds up, putting you closer to your maximum heart rate. Anaerobic exercise differs from aerobic activity in other ways, too. Working out within this training zone isn't associated with prolonged physical activity required during aerobic exercise. Rather, anaerobic exercise is associated with activities that require short, intense bursts of energy. Working out in the aerobic zone has your heart pumping at between 70 percent and 80 percent of its maximum. Your anaerobic zone is somewhere between 80 percent and 90 percent of your MHR. Anaerobic exercise causes a brief increase in blood pressure, however it helps lower overall blood pressure over time.
Steady State Training
During the initial minutes of steady state exercise, oxygen uptake rises exponentially and will reach a plateau between the 3rd and 4th minutes. Once a plateau is reached, it remains stable for the duration of the exercise. This steady rate reflects the balance between energy required by the working muscle and ATP production during aerobic metabolism. In theory, once steady state is reached a low to moderate exercise can continue indefinitely if the individual possessed the will to continue. However, in real life this is not the case. To maintain a steady state activity indefinitely it is assumed that aerobic metabolism solely determines the capacity to sustain submaximal exercise. In reality, fluid loss and electrolyte depletion as well as the availability of energy substrates such as muscle glycogen may limit the performance during a prolonged submaximal exercise.
Electromyography
EMG; a diagnostic test that measures the electrical activity within muscle fibers in response to nerve stimulation.
Peripheral Fatigue
Electrical activity remains the same but biochemical changes in muscle prevent contraction. These include failure of action potential to be conducted along fibre, lactic acid build up which affects muscle proteins, inhibition of cross-bridge cycling (due to build up of ADP and Pi) and ATP hydrolysis producing H+ ions.
Central Fatigue
Failure of appropriate regions of the cerebral cortex to send excitatory signals to motor neurons. Athletes performance depends not only on physical state of muscles but also on "will to win".
Fatigue
Fatigue represents the decline in muscle tension or force capacity with repeated stimulation or during a given time period. All voluntary muscle actions have four main components that occur in the following order: Central Nervous System, Peripheral Nervous System, Neuromuscular Junction and the Muscle Fibre. Fatigue occurs from interrupting this chain no matter the reason. Some examples: 1. Reduced glycogen in the active muscle 2. When the action potential fails to cross from the motor neuron to the muscle fiber 3. Lack of oxygen in the muscle and increased level of muscle lactate relate to muscle fatigue 4. Alterations in the levels of CNS neurotransmitters
Glycolysis
Glycolysis is the predominant energy system used for all-out exercise lasting from 30 seconds to about 2 minutes and is the second-fastest way to resynthesize ATP. Fuel: Blood Glucose, Muscle and Live Gycogen
Golgi Tendon Organ- How it works as a reflex
How it works as a reflex: 1) Golgi tendon organ is stimulated by excessive tension 2) An afferent nerve fiber rapidly sends sensory information to the spinal cord 3) This elicits autogenic inhibition (relaxes) of the agonist muscles under tension and elicits reciprocal activation of the antagonist muscle. Example: A) Arm Wrestler
Muscle Spindles- How it works as a reflex
How it works as a reflex: 1) Muscle spindle senses a change in length (stretch) in the muscle 2) An afferent (sensory) nerve fiber carries the sensory impulse from the spindle to the spinal cord 3) Then the efferent (motor) spinal cord motor neuron activates the muscle being stretched causing it to contract (concentric) and signals to inhibit (relax) the antagonist muscle (reciprocal inhibition - reflex relaxation in response to the contraction of the agonist) Examples: A) Knee Jerk Reflex B) Standing/Stature
MET (Metabolic Equivalent of Task)
Rate of energy expenditure at rest; 1 MET is the equivalent of a VO2 of 3.5 mL/kg/min. , A MET is the unit of measurement for the amount of oxygen used by the body during physical activity.
"Hitting the Wall"
In the cases of high intensity exercise sustained for a prolonged amount of time (such as a marathon) availability of liver glycogen becomes increasingly important for central nervous system function. In severe cases, a depletion of liver glycogen can result in what we call "hitting the wall" where one will lose the ability to maintain proper bodily functions and become disoriented.
Short Interval Training
Interval training, as other forms of physiological stressor overloads the specific energy system(s). Short interval training (30 sec reps) mostly affects the phosphagen cycle, myoglobin content, glycogen catabolism.
Contract-Relax-Antagonist-Contract (CRAC)
Involves static stretching + a combination of CR and AC. 1) Move the joint until the point of muscular restriction in the target muscle through contraction of antagonist muscle 2) Instruct the subject to perform a brief isometric contraction of the target muscle against a fixed resistance. 3) Relaxation and further passive elongation by active dynamic concentric contraction of antagonist Mechanism: Golgi tendon organ, autogenic inhibition (inverse myotatic reflex) and reciprocal inhibition.
Antagonist-Contract (AC)
Involves static stretching + contraction of the antagonist muscle 1) Move the joint until the point of muscular restriction in the target muscle 2) Instruct the subject to perform a brief isometric contraction of the antagonist muscle against a fixed resistance. 3) Relaxation and joint is moved to a greater range of motion (ROM) by a force applied to the limb by another person. Mechanism: Golgi tendon organ and reciprocal inhibition.
Contract-Relax (CR)
Involves static stretching + contraction of the muscle being stretched. 1) Move the joint until the point of muscular restriction in the target muscle 2) Instruct the subject to perform a brief isometric contraction of the target muscle against a fixed resistance. 3) Relaxation and joint is moved to a greater range of motion (ROM) by a force applied to the limb by another person. Mechanism: Golgi tendon organ, autogenic inhibition, (inverse myotatic reflex).
Reactive Hyperemia; Isometric Contractions then Relax
Isometric Exercise. post-occlusion hyperemia; increased blood flow to tissue after period of decreased blood flow; O2 debt during the decreased blood flow period needs to be "repaid"
Long interval Training
Long interval training (>5 min) has an impact on the oxidative pathway.
Maximum Aerobic Speed
Maximum aerobic speed (MAS) relates to aerobic performance (VO2max) and forms part of the process for developing aerobic capacity and is expressed in meters/second (m/sec).
Proprioreceptors
Muscles and tendons contain specialized sensory receptors sensitive to stretch, tension and pressure. These sensory receptors are called proprioceptors and they rapidly relay information about muscular dynamics and limb movement to conscious and subconscious portions of the CNS. There are two main proprioceptors located in the muscles and tendons, the muscle spindles and the golgi tendon organ.
Valsalva Manoeuvre
Occurs when the individual attempts to exhale while the mouth, nose and glottis are closed. Slows heart rate and AV conduction. Common on lifting heavy objects, pressure on carotid sinus, and distension of bladder. Increased venous return, preload and therefore cardiac output results in an increased aortic pressure with compensatory 'overshoot' of blood pressure.
Proprioceptive Neuromuscular Facilitation (PNF) Stretching
PNF- partner technique involves contracting, relaxing, and stretching the opposite muscle group to achieve greater range of motion. During PNF stretches, three techniques are used to increase the range of motion. The three PNF stretching techniques are: (1) hold-relax, (2) hold-relax with agonist muscle contraction, and (3) contract-relax. The stretching techniques differ based on the muscle contractions used in the second and third phases (1,2). Both isometric and concentric muscle contractions of the antagonist are used before applying a passive stretch of the antagonist to bring about autogenic inhibition. The isometric muscle contraction is termed "hold" and the concentric muscle contraction is termed "contract." A concentric muscle contraction of the agonist is used during passive stretching of the antagonist muscle group to cause reciprocal inhibition.
Phosphagen System
Provides ATP primarily for short-term, high-intensity activites (resistance training and sprinting) and is active at the start of all exercise regardless of intensity. (Anaerobic exercise uses this) Fuel: Creatine Phosphate and stored ATP
Perceived Exertion
RPE determines exercise intensity levels. A method to estimate your level of exercise by how you feel such as changes in breathing, heart rate, sweating, and fatigue.
Why do some muscle groups fatigue more rapidly than others when using the same relative resistance?
Some muscle groups consist of more slow twitch muscle fibres than fast twitch muscle fibres. Slow twitch muscle fibres are more resistant to fatigue. Also some muscle groups simply contain more muscle fibres all together, so fatigue will take longer to set in. Quadriceps are much larger and contain more slow twitch fibres than the biceps therefore will take longer to fatigue. Also, the quads are used more often than the biceps so they may be trained to resist more fatigue.
Target Heart Rate Equation (Karvonen) (Male)
THR= [(MHR - RHR) X % intensity] + RHR THR=Target Heart Rate MHR=Maximum Heart Rate (220-age) RHR=Resting Heart Rate (bpm when at rest) BPM=Beats Per Minute HRR=Heart Rate Reserve (Difference between MHR and RHR) % Intensity=Usually 60 and 80 percent
Diastolic Blood Pressure
The amount of force (pressure) that blood exerts on the walls of the blood vessels as it passes through them while the heart is at rest. The lower, bottom, number of the two measurements.
Interpolated Twitch Technique
The application of a strong, brief pulse applied during a maximal voluntary isometric contraction. Any augment in force is a result of the pulse activating portion of motor unit pool that was not fully activated by CNS.
Systolic Blood Pressure
The blood pressure exerted on the walls of the arteries, measured during the period of ventricular contraction; in blood pressure readings, it is the higher, upper number of the two measurements
What are the 3 types of metabolic systems?
The three metabolic energy pathways are the phosphagen system, glycolysis and the aerobic system.
Aerobic System
The slowest energy production system in the body. It is fueled by carbohydrates, or fats and proteins, and requires oxygen, it can last from 1.5-3 hours, as long as there is enough glucose, fluids, and oxygen in the body. Fuel: Blood Glucose, Muscle and Liver Glycogen, Adipose and Intramuscular fat.
Determining Aerobic Speed
To determine aerobic speed for an activity one would use the maximum aerobic speed (determined from a MAS test) and multiply it by the intensity one wishes to maintain. For example, if an individuals' maximal aerobic speed (MAS) was 18 Km/hr and needs to sustain 70% of MAS during exercising; then he simply multiplies 18 Km/hr by 0.70 resulting in a desired speed of 12.6km/hr. However, in a field test one generally does not have the means to monitor an individual's speed on a regular basis. Knowing that heart rate is related to aerobic speed (effort) one can use the Karvonen equation to determine target heart rate for a desired activity.
Some examples of how you may voluntarily raise or lower your heart rate. How could this benefit you in some sport situations?
Valsalva Manoeuver. Breathing Techniques. Mental Imagery. Relaxation. Etc. This could benefit you if you need to prepare for the next shift or next play in a sport. Example: Mark Messier was able to efficiently lower his heart rate in between shifts, and could perform at max level more efficiently throughout the game. Healthy lifestyle and Exercise is a factor in the ability to achieve this however.
Golgi Tendon Organ Function
What it does: Detects differences in the tension generated by active muscle rather than muscle length. They respond to: 1) tension created in the muscle when it shortens and (2) tension when the muscle stretches passively.
Muscle Spindles Function
What it does: Provides sensory information about changes in muscle fiber length and tension. They detect, respond to, and modulate changes in the length of extrafusal muscle fibers. Through reflex response, they initiate a stronger muscle action to counteract the stretch.
Active Hyperemia
You get active hyperemia in metabolically active tissues. If you start running, your muscles will start consuming oxygen and producing CO2 more quickly than the circulatory system can respond. So CO increases, pH decreases in the muscle. The muscle will also eventually produce nitric acid because they don't have adequate blood supply. Increases in metabolites by actively exercising tissues causes vasodilation which causes an increase in blood supply.
Difference between Central and Peripheral Fatigue
peripheral fatigue originates in the exercising muscles; central fatigue begins in those various areas of the brain working in concert, and which sent efferent signals to the working muscles to ease strength of contraction in order to preserve homeostasis.
