Week 4 - Speed Training

Question 1

According to Gaitanos et al., (1993) what is the percentage contribution of glycolysis to total ATP resynthesis during a 6-second all-out effort?

Answer 1

44.1%

Question 2

There’s evidence to suggest that speed training leads to an ⬆️ in activity of glycolytic enzymes.

List 3 of these

Answer 2

PK (Pyruvate kinase)

Enolase

TPI (Triose P Isomerase)

Question 3

Function of PK

Answer 3

Phosphoenolpyruvate + ADP + H+ –> pyruvate + ATP

in glycolysis.

Question 4

Function of enolase

Answer 4

2-phosphoglycerate –> phosphoenolpyruvate + H20

Question 5

Function of TPI (Triosephosphate isomerase)

Answer 5

Dihydroxyacetone P – triose P isomerase –> glyceraldehyde 3-P

Question 6

According to Gaitanos et al., (1993) what is the percentage contribution of the PCr system to total ATP resynthesis during a 6-second all-out effort?

Answer 6

57%

Question 7

PCr stores deplete during an all out sprint.

– Replenished during recovery period.

Which energy system provides ATP for this recovery?

Answer 7

Myokinase pathway

Question 8

What is the name of the enzyme involved in the myokinase pathway

Answer 8

Myokinase / ADK - Adyenlate kinase

Question 9

Equation for myokinase reaction

Answer 9

ATP + AMP <=> 2ADP

Question 10

Dawson et al., (1998) + Thorstensson et al., (1975) found a significant increase in the activity of the myokinase / ADK. What percentage increase did they report?

Answer 10

19%

Question 11

During an all-out sprint we activate our Fast Fatigable (FF) motor units.

Do they have a low, moderate or high innervation ratio?

Answer 11

High innervation ratio

Question 12

What does the innervation ratio refer to?

Answer 12

Defines the no. of muscle fibres innervated by a single motor neurone.

Question 13

What motor neuron does the action potential travel down after leaving the spinal cord?

Answer 13

Somatic motor neurons (alpha motor neuron)

Question 14

Define speed

Answer 14

Ability to move the body as quickly as possible over a set distance. Associate it w/ max-intensity exercise lasting 2-10s.

Question 15

How to calculate speed

Answer 15

Distance / time

Question 16

How to assess speed in the field

Answer 16

Stopwatch

Timing gates (more accurate)

Question 17

In what way can speed be improved

Answer 17

By enhancing the tension + length-impulse response involved in the rapid exchange between eccentric + concentric muscle action during sprint activity.

Question 18

Why is use of plyometric or explosive strength training an adv. to speed development?

Answer 18

Due to improvements seen in the stretch-shortening cycle (SSC).

Question 19

Main adaptations over prolonged speed training

Answer 19

⬇️ muscle stiffness

Enhanced NM activation

Question 20

At which point can olympic-caliber athletes accelerate through in a 100m sprint

Answer 20

70m mark

Question 21

Define 1 stride

Answer 21

2 steps/foot strikes

Question 22

Define stride rate

Answer 22

No. of steps taken w/ each leg during distance of run.

Question 23

What stride rate do elite sprinters have

Answer 23

Approx 5/sec

Question 24

What happens as stride rate increases

Answer 24

Time spend on ground ⬇️ = flight phase ⬆️.

Question 25

Constant stride length + ⬆️ stride rate = ?

Answer 25

⬆️ speed

Question 26

Constant stride rate + ⬆️ stride length = ?

Answer 26

⬆️ speed

Question 27

Which is more important when determining runners Max velocity

Answer 27

Stride rate

Question 28

In regards to running, what does improved power allow

Answer 28

Athlete can ⬆️ acceleration ability by ⬇️ ground contact time of each stride + ⬆️ impulse production on takeoff.

Question 29

MUSCLE FIBRE-TYPE COMPOSITION What is speed influenced by?

Answer 29

Structural architecture of skeletal tissue: - Muscle thickness - Length of fascicle - Pennation angle of fascicles

Question 30

What does a large pennation angle allow?

Answer 30

Ability to generate greater force - associated w/ greater speed of contraction.

Question 31

Typical speed training programme

Answer 31

3-4 sessions/week 4-20 reps per session Less than 10secs of exercise per rep 90-100% max. Speed Work:Rest > 1:6

Question 32

Benefits to resisted speed training

Answer 32

Enhanced neural function ⬆️ reflex potentiation ⬆️ type II muscle fibre cross-sectional area

Question 33

Cautions to resisted speed training

Answer 33

Greater resistance may damage running technique, negating any pot. benefit from resisted running.

Question 34

Recommendations for resisted running drills

Answer 34

18-37m 3-4 sets of 4-8 reps Recovery - 90-120s

Question 35

Assisted speed or overspeed training

Answer 35

Uses downhill sprint or implements to help athletes run faster than they normally do. — Can ⬆️ stride freq. + length more than possible w/ traditional sprint exercises.

Question 36

-ive outcome to assisted speed or overspeed training

Answer 36

Risk of changing running technique = slower sprint times. — Been recommended that athletes don’t exceed 100% of their max. Running speed.

Question 37

Metabolic adaptations to speed training

Answer 37

⬆️ activity of creatine kinase, myokinase + glycolytic enzymes. ⬆️ proportion of type II muscle fibres. ⬆️ muscle fibre cross-sectional area.

Question 38

What pathways majorly contribute to ATP resynthesis during all out sprints

Answer 38

PCr + glycolytic

Question 39

Influence of speed training on motor unit recruitment / neural adaptations

Answer 39

⬆️ motor neurone firing freq. ⬆️ conduction velocity ⬆️ proportion + activation of type 2 motor units/fibres Enhancement of SR Ca2+ release

Question 40

What causes Ca2+ release from SR? What happens after?

Answer 40

AP travelling down T-tubule Ca2+ Binds to troponin = Allowing binding of actin + myosin == Contraction.

Question 41

Pathway of AP from start to muscle fibres

Answer 41

Down spinal cord Branches into somatic motor neurones (alpha motor neurone) Transmits AP towards skeletal muscle. Each alpha motor neurone attaches to multiple muscle fibres.

Question 42

What does an AP travelling down a motor neurone cause?

Answer 42

Contraction in all fibres innervated by that neurone.

Question 43

What happens with regards to a single AP?

Answer 43

Contraction of the fibres - a twitch.

Question 44

What is req. for sustained + forceful muscle contraction in association with AP?

Answer 44

Successive motor neurone APs

Question 45

What is the force + speed of contraction affected by?

Answer 45

Freq. of AP from motor neurones No. of motor neurones transmitting AP.

Question 46

What are the 3 motor unit types

Answer 46

Fast Fatigable (FF) Fast fatigue-resistant (FR) Slow (S)

Question 47

What is the histochemical profile of fibres of the 3 motor unit types

Answer 47

FF -- FAST GLYCOLYTIC (FG) FR -- FAST OXIDATIVE GLYCOLYTIC (FOG) S -- SLOW OXIDATIVE (SO)

Question 48

Order motor unit size from FF to S motor unit types

Answer 48

FF -Large FR - Medium S - Small

Question 49

Order INNERVATION RATIO from FF to S motor unit types

Answer 49

FF - High innervation ratio SO - Low innervation ratio

Question 50

Advice for ind. aiming to ⬆️ speed

Answer 50

Speed training Resistance training (Traditional, High velocity + power) Plyometrics Movement Specific Training (Resisted Sprints).

Question 51

How many sprints are performed in a team sports game?

Answer 51

Typically 25-40

Question 52

How long are the sprints performed in a team sports game?

Answer 52

2-4s

Question 53

How far are the sprints performed in a team sports game?

Answer 53

15-25m

Question 54

Heavy resistance vs. high velocity/power training

Answer 54

Heavy resistance training ⬆️ maximal muscle force prod. Explosive power training ⬆️ maximal muscle force prod + rate of force development == Both should be incorporated into a sprinters programme.

Question 55

When is muscle excitability reduced?

Answer 55

When K+ builds up outside the muscle cell.

Question 56

How does speed training prevent a reduction in muscle excitability?

Answer 56

⬆️ no. of Na+-K+ ATPase pumps

Question 57

Why is more Ca2+ released from the SR after speed training?

Answer 57

⬆️ in SERCA and RyR

Question 58

What is a high leg muscle volume typically associated with?

Answer 58

Acceleration

Question 59

What is the initial improvement in strength following the onset of resistance training due to?

Answer 59

Neural adaptations

Question 60

To what type of speed training is there currently limited evidence to support the use of it?

Answer 60

Assisted sprints.