Physiology of Exercise Flashcards
Cardiac Output
Product of heart rate and stroke volume (quantity of blood pumped per heartbeat)
Angina
Pressure or tightness in chest (or arm, jaw, or shoulder)
Collagen
Most abundant protein in the body: inflexible
structures containing large amount of collagen tend to limit motion and resist stretch; main constituents of tendons and ligaments that are subjected to pulling force
Positive Risk Factor: Dyslipidemia
LDL ≥ 130 mg/dL
HDL < 40 mg/dL
Steady State
When the energy and physiological demands of the exercise bout are met by the physiological systems in the body
Positive Risk Factor: Sedentary
Less than 30 m 3x/week of exercise in last three months
First Ventilatory Threshold (VT1)
aka Anaerobic or Lactate Threshold
When lactate begins to accumulate in blood faster than it can be cleared, which causes a person to breathe faster in an effort to blow off the extra CO₂ produced by the buffering of acid metabolites
When fats are primary fuel (below VT1), the demand for O₂ is met by increasing tidal volume (taking deeper breaths).
Positive Risk Factor: Cigarettes
Current smoker or quick within six months
Autogenic Inhibition
Relaxation of muscle due to contraction in antagonist muscle group due to GTO activation
—–> prevents tearing of muscle
Systolic Blood Pressure
Represents pressure created by the heart as it pumps blood into circulation
= one cardiac cycle’s greatest pressure
= higher number in blood pressure measurement
Minute Ventilation (VE)
A measure of the amount of air that passes through the lungs in one minute; tidal volume multiplied by ventilatory rate
Elastin
Made up of amino acids, elastin (elastic muscle fibers) determines possible range of extensibility of muscle cells and succumbs readily to stretching
–> Almost always found with collagen fibers, which work together to support and facilitate joint movement
Negative Risk Factor: HDL Cholestorol
≥ 60 mg/dL
Diastolic Blood Pressure
Represents pressure exerted on the artery walls as blood remains in arteries during filling stage of cardiac cycle (between beats)
= minimum pressure during one cardiac cycle
= lower number in blood pressure measurement
Positive Risk Factor: Obesity
BMI ≥ 30
Hypertension HR
SBP: 140 or above; DBP 90 or above
Two main areas to measure heart rate
Wrist (radial artery) and neck (carotid artery)
Golgi Tendon Organ (GTO)
Senses increased tension within its associated muscle when the muscle contracts or is stretched
- ->When muscle tension is reduced due to fatigue, GTO output is reduced, allowing muscle to increase its contractile ability
- ->GTO activation results in an enhanced contraction of the antagonist muscle group
Ratings of Perceived Exertion
Category Ratio Scale 0–10
Positive Risk Factor: Prediabetes
Fasting plasma glucose ≥ 100 mg/dL
Active Isolated Stretching
Hold stretch for 2 seconds, then back to starting point
Several repetitions, increasing stretch by a few degrees each time
Vagal Withdrawal
When exercise begins and the sympathetic nervous system (fight or flight) takes over
Positive Risk Factor: Hypertension
SBP ≥ 140 mmHg
DBP ≥ 90 mmHg
Differences between Type IIa and Type IIx Muscle Fibers
Type IIx: cannot sustain effort for more than a few seconds; high anaerobic capacity; largest and fastest and create most force; less efficient
Type IIa: used in strength and power activities but can sustain effort longer than IIx (three minutes in highly trained athletes)