Physiological adaptations Flashcards
(25 cards)
What is sub maximal exercise?
Exercise performed at a level that leaves the heart rate in a plateau below its max no. of beats per min
(PLATEAU = Consistent rate for an extended period of time)
What is maximal exercise?
Activity that leads to a heart rate that approaches its max level
What is Rest?
A state where no extra demands are placed on the body
What is a resting heart rate?
No. of beats per min
INCREASES
Amount of O2 required at rest is determined by BMR - basal metabolic rate
Reliable indicator of how hard heart working
Athlete = lower heart rate = efficiency of cardiovascular system and higher Stroke volume
What is the main reason for the fall in resting heart rate?
Increase in Stroke volume
Allows more blood to be pumped in the heart per min
What is Diastole?
Relaxation phase of cardiac contraction
What is stroke volume?
Amount of blood ejected by the left ventricle during a contraction (mL/BEAT)
DECREASES
Trained athletes = higher sv
More blood pumped = more oxygen to muscles → better, longer, faster performance.
SV determines amount of blood being circulated & how much o2 delivered to working muscles
Why is stroke volume notably higher at maximal exercise following an endurance program?
Because training causes left ventricle to fill more completely during diastole than an untrained heart
More blood in circulation following training as a consequence of an increase in blood plasma volume
(MORE BLOOD ABLE TO ENTER VENTRICLE)
When stroke volume occurs, what happens to ventricle?
Greater stretch in the ventricular wall increases elastic recoil, allowing more powerful contractions and less blood left after systole.
Increased O2 to working muscles = improved performance
What is cardiac output?
SV X HR
INCREASES
Amount of blood pumped out of heart each minute (L/Min)
Higher CO - Result from increase in SV
What is oxygen uptake?
INCREASE - Amount of oxygen the body uses in 1 minute (Litres)
Aerobic training increases persons max O2 uptake
Body consumes small amounts of O2 at rest. As we begin exercise, mitochondria in cells use more oxygen for energy
BEST INDICATOR OF CR ENDURANCE - max O2 muscles can absorb & use for work
What is lung capacity?
RELATIVELY UNCHANGED (REST & SUB MAX) BUT INCREASES AT MAX LEVELS OF EXERCISE
Volume of air in lungs as a result of max inspiration
NO. breaths taken during max exercise can increase
= as the muscles around the lungs become larger & stronger
Size of lungs increase slightly, allowing for greater volume of O2 to be inhaled
What is vital capacity?
Amount of air that can be expelled after max inspiration, this will increase slightly
What is residual volume?
Amount of air that cannot be moved out of the lungs, shows a slight decrease
What is tidal volume?
Amount of air breathed in and our during normal respiration
What is Haemoglobin level?
Compound of red blood cells that carries O2 around body for aerobic respiration
Low O₂ during training triggers more red blood cells and haemoglobin production.
Training increases haemoglobin, especially at high altitudes, boosting O₂ capacity.
Plasma volume also rises, thinning the blood, so endurance athletes have more blood but lower concentration than non-athletes.
What is Muscle hypertrophy?
Muscle growth together with an increase in size of muscle cells
- Length unchanged, size of muscle becomes larger = increase in mass & cross sectional area
Needs to address overload principle to encourage term & specificity
What is muscle hypertrophy induced by?
Training programs that stimulate activity in muscle fibres causing them to grow
What is Muscular atrophy?
Without stimulation - muscle fibres reduce in size
The growth and cross sectional size increase of muscle is a direct result of mass increases in:
- Actin and myosin filament
= thin protein filaments that produce muscle action - Myofibrils
= contractile elements of skeletal muscle - Connective tissue
= tissue that surrounds & supports muscle
What does the extent of hypertrophy depend on?
- Muscle type (fast & slow twitch, white & red muscle fibres
- Type of stimulus - progressive overload, resistance training, using low reps, high resistance
- Regularity of training
- Availability of body hormones
What is slow twitch muscle fibres?
- Greater capillaries which promotes greater O2 supply and contract slowly, long period of time, releasing energy gradually
- Increased mitochondria, more fuel for aerobic energy pathways
(JOGGING, CYCLING, ENDURANCE SWIMMING)
Adaptations for Slow twitch muscle fibres)
- Hypertrophy - endurance activity, some growth in fibres
- Increase in capillary supply boosts efficiency by enhancing gas exchange
- Mitochondrial function - increased which means more O2 is transported to cells, increase in size & efficiency in using O2 to produce ATP
- Oxidative enzymes - making production more efficient
- Myoglobin content - transporting O2 from cell membrane to mitochondria & storing for when necessary
Endurance training increases myoglobin levels
What is fast twitch muscle fibres?
Reach peak tension quickly, recruited for power & explosive movements
Fewer capillaries & mitochondria
Faster metabolism of ATP
Capable of faster & more powerful stimulation
(WEIGHTLIFTING, JAVELIN THROWING & SPRINTING)
