Chapter 17 (Metabolism and Exercise) Flashcards
Short term changes to circulatory and respiratory system when exercising?
Respiratory system:
Heart rate increases
Vasodilation of arterioles in skeletal muscles
Increased blood flow to active muscles
Increased stroke volume
Reduced blood flow to digestive system
Vasodilation to arterioles supplying surface of skin
Circulatory system:
Increased breathing rate
Increased depth of breathing
Increased stroke volume
What are short term consequences of exercise - Definition
Changes which occur during the period of activity.
What are long term consequences of exercise?
Changes which occur as a result of the body adapting as a result of regular training?
Government recommendations for exercise?
16-64 year old should be active every day.
150 minutes moderate intensity activity in 10 minutes or more bouts.
eg, 30mins exercise 5 times week
or 75 minutes vigorous activity across wee.
Strength training on at least 2 days per week.
Why does heart rate increase during exercise?
caused by incr. in adrenaline secretion
incr. in stimulation of the sympathetic NS
incr. anticipatory response –> release of NT (e.g. adrenaline and noradrenaline)
HR increases proportional to exercise until plateau/max h.r. reached
Why does vasodilation of arterioles in skeletal muscles occur during exercise?
secretion of nitric oxide by arteriolar endothelium
in response to fall in O(2) levels
Ways of enhancing athletic performance?
Carbohydrate loading
RhEPO
Blood doping
Steroid enhancement
Why does stroke volume increase with exercise?
more blood returns to left atrium
∴ larger volume of blood filling ventricle in diastole
∴ greater volume of blood pumped out in systole
Why does breathing rate and tidal volume increase with exercise?
more air into alveoli –> incr. in concentration gradient ∴ O(2) can diffuse into the blood more easily
∴ incr. rate of aerobic respiration ∴ more CO(2) produced ∴ more H(2)CO(3) produced
incr. in blood acidity detected by chemoreceptors - sends impulses to respiratory centre in medulla
incr. in rate and extent of contractions of diaphragm and intercostal muscles
Why does blood flow to the
Finish the short term changes
What are the long term effects of exercise?
Circulatory:
Respiratory:
Skeletal:
Definition of aerobic respiration?
A measure of the ability of the heart and lungs to respond to the demands of aerobic exercise.
What are the three indicators of aerobic respiration?
efficiency of GES/CVS
extent of aerobic respiration without fatigue
efficiency of respiration
How is aerobic fitness achieved?
20 mins of exercise
3 x per week
increasing in intensity to 50-55% of VO2 max
or 70% of MAX HR (220-age)
Factors which affect aerobic respiration?
age
gender
smoking
malnutrition
motivation
programme
alcohol consumption
stimulants
depression
give four health benefits of regular aerobic exercise
strengthened skeletal muscle
improved circulatory efficiency
reduced blood pressure
improved mental health
reduced risk of diabetes
stimulate bone growth
How can aerobic exercise be improved?
(FITT) increase: - Frequency - Intensity - Type - Time (i.e. duration)
how is aerobic fitness measured?
decr. resting h.r.
decr. recovery time
incr. VO2 max
how does a successful training programme bring improved aerobic fitness?
successful training will act as a stressor
body adapts by undergoing physiological and biochemical changes.
progressive overload –> prevents plateau
Definition of VO2 Max?
Maximum rate at which oxygen can be taken in, absorbed, transported and used as measured during incremental exercise.
safety consideration!!!
Prior to any investigation, consent needs to be given.
Check participants for:
asthma
heart conditions
pregnancy
high blood pressure
Participants also need to have had appropriate equipment training.
How to measure success of a training programme?
Changes in HR (decrease)
Changes in recovery time (shorter)
Changes in VO2 mac (larger)
What are physiological changes that could occur?
Normal cells
hypertrophy (cells have enlarged)
hyperplasia (more cells)
Biochemical changes that could occur?
Inc. in myoglobin
Inc. in actin
Inc. in myosin.
(all intracellular proteins)
