O2 capacity, strength & flexibility Flashcards
what is O2 capacity ?
the ability to take in, transport and use O2 to sustain prolonged periods of aerobic maximal work
what is VO2 max ?
the maximum volume of O2 transported and used per minute during maximal exhaustive exercise
what is VO2 max measured in ?
ml/kg/min
the higher % VO2 max, the higher potential what ?
O2 capacity
which sports is O2 capacity a key component for ?
- marathon runner
- centre/wa netball
- midfielder in football
- tour de France
- 2000 m rowing
- rugby forwards
what is strength ?
the ability of the neuromuscular system to apply a force - against a resistance
what are the 3 types of strength ?
static
dynamic - explosive, maximum, endurance
what is static strength ?
ability of NMS to exert and apply a force while the :
muscle length remains static
isometric contraction
no movement occurs
give an example of static strength ?
any held balance
crucifix on rings
scrum in rugby
what is dynamic strength ?
ability of NMS to overcome a resistance where :
muscle length changes
isotonic contraction
movement does occur
power moves = speed + strength
give an example of dynamic strength ?
most sports
long jump
400 m sprint
what is explosive /elastic strength ?
ability of NMS to expand a maximal force in one or a series of rapid muscle contractions
what does explosive strength include ?
-stretch reflex mechanism (elastic recoil)
involves eccentric contraction
- lasts 10 seconds or less
give an example of explosive strength ?
- triple jump
- volleyball spike
- somersault
what is maximum strength ?
ability of NMS to exert a maximal force in a single voluntary contraction
what does maximum strength include ?
-maximum weight lifted once
- 1 rep max
give an example of maximum strength ?
olympic dead lift
what is endurance strength ?
ability of NMS to sustain / withstand repeated muscle contractions ( or single isometric contraction ) over time )
what does endurance strength include ?
repetitive actions / force applied
increased resistance to fatigue
give an example of endurance strength ?
rowing
swimming
tour de France
pistol shooting (static)
what is flexibility ?
range of motion ( ROM ) around a joint or a series of joints
what is static flexibility ?
the static ROM around a joint or series of joints ( no joint motion )
what is static active ?
when a performer actively contracts an agonist muscle to move a joint just beyond its point of resistance
give an example of static active stretching ?
leg lift / arabesque
what is static passive stretching ?
when a joint is moved just beyond its point of resistance with assistance, e.g partner, gravity, other body part, object
give an example of static passive stretching ?
block for oversplits
give an example of static stretching ?
arabesque
what is dynamic flexibility ?
resistance of a joint to a movement
ROM while a joint is moving at speed
give an example of dynamic flexibility ?
leg swings
what can a good static ROM be a good prerequisite for ?
increased dynamic ROM
what factors affect VO2 max / aerobic capacity ?
individual physiological makeup
age
aerobic training
gender
what are the affects of individual physiological makeup affect VO2 max ?
- the greater the efficiency of
body systems to transport and utilise O2 = higher VO2 MAX can be determined by genetics - fibre types
why does physiological makeup affect VO2 max ?
- stronger respiratory muscles = take in /consume O2
- larger heart - pump blood around body
- higher stroke volume
- Higher number of capillaries, RBCS , SO fibres - transport O2
how can age affect VO2 max ?
VO2 max peaks in early 20s
VO2 max declines by 1% a year once physiological peak is reached
why does age affect VO2 max ?
- decreased O2 transport to muscles
- decreased efficiency of body systems
- Max HR/SV/Q to tissues decreases due to decreased left ventricle elasticity and contractility
- decreased elasticity in lungs/ chest walls
what affect does training / aerobic training have on VO2 max ?
- aerobic training increases VO2 max up to 20%
why does training affect VO2 max ?
- increased long term O2 adaptations, e.g hypertrophy, capillarisation, muscle mitochondria
- adaptations to heart, lungs, blood = higher VO2 max
what affect does gender have on VO2 max ?
females have up to 30% lower VO2 max than males
why does gender have an affect on VO2 max ?
- females have smaller body size
- have smaller lung volumes and O2 intake
- smaller heart volumes and lower haemoglobin levels - lower VO2 max
- increased female body fat
what factors affect strength ?
- cross sectional area of muscle
- fibre type
- gender
- age
- training
how does cross sectional muscle area affect strength ?
greater CSA = greater strength/ force of muscle contraction generated
why does muscle CSA affect strength ?
strength increases per cm of muscles which increases the force and speed of muscle contraction
how does fibre type affect strength ?
greater % of fast twitch fibres the greater the speed/force generated over a short period
greater % of slow twitch fibres higher the fatigue resistance
why does fibre type affect strength ?
- fast twitch fibres have :
- larger, thicker, myelin sheath, larger motor neurones/ units which stimulate more muscle fibres which increase the speed/force contraction
- slow twitch fibres are smaller, have increased capillarisation, increased mitochondria density, increased myoglobin
this lowers speed/force, but has higher fatigue resistance
how does gender affect strength ?
males have a higher strength than females
why does gender affect strength ?
- males have increased hormone testosterone levels
- this gives them higher muscle mass and CSA
what affect does age have on strength ?
- strength decreases from age after peak strength reached:
- females : 16-25 yrs
- males : 18 -30 yrs
why does age affect strength ?
- decrease in muscle mass/CSA
- decreased testosterone, elasticity of CT’s and efficiency of NMS
what affect does strength training have on strength ?
applying a force against a resistance increases strength
why does strength training affect muscle mass ?
- overload increases muscle hypertrophy
- reversibility: if training stops, adaptations reverse
which factors affect flexibility ?
joint type
length and elasticity of surrounding connective tissue
gender
age temperature
training
obesity/muscle mass
what affect does joint type have on flexibility ?
- ball and socket joint has greater ROM than condyloid joint
- hinge = 1 plane
- pivot = 1 plane
- B&S = 3 planes
greater ROMis determined by joint shape of articulating bones
why does joint type have an affect on flexibility ?
size and shape of joint and their articulating bones can aid and limit ROM
- hip joint = deep socket = less flexibility more stability
- shoulder joint = shallow socket = more flexibility less stability
what affect does the length and elasticity of connective tissues have on flexibility ?
- greater length and flexibility of surrounding, muscles, tendons and ligaments, greater ROM
- greater ROM before stretch reflex is initiated
why does the length and elasticity of CT’s affect flexibility ?
- greater length, greater the distance before stretch reflex is reached
- stretch reflex inhibits further ROM
what affect does gender have on flexibility ?
females are generally more flexible than males
why does gender affect flexibility ?
females have increased levels of relaxin and oestrogen
this increases elasticity of CT’s
what affect does age have on flexibility ?
flexibility decreases with increasing age, greatest in childhood
why does age affect flexibility ?
age decreases due to loss of elasticity and increased calcification of CT’s
what affect does temperature have on flexibility ?
increased temperature increases joint and muscle ROm
after a warm up
what affect does obesity/muscle mass have on flexibility ?
decreases ROM
what affect does stretch training & reversibility have on flexibility ?
- elasticity/ROM decreases without stretching
