Lab Session 1
Power-velocity relationships during sprint cycling and Wingate Tests
Strength: Maximum force generated by a muscle
Low velocities
High forces
Speed: Maximum velocity
High velocities, low forces
Power = Force (N) x Velocity
Strength x speed
Measuring Force and Contraction Velocity in an Isolated Muscle
You can attach a muscle to a force transducer at one end
and a fulcrum with weight at the other. The weight will
stretch the muscle, and then by stimulating the muscle
electrically you can measure the force and velocity of the
muscle.
The Force Velocity Relationship
When force is high velocity is low and when velocity is high force is low.
This is because with a very high velocity
contraction less myosin heads are attached
to actin at a time because as they pull actin
across they have to release in order to keep
actin sliding across.
Whereas in order to produce a high force
you need more myosin attached to actin
and therefore you cannot contract quickly.
When you calculate power you create
an inverted u shaped curve and your
Maximum power is at about a third of
your maximum contraction velocity
Shape of force velocity curve is
dependent on fibre type in the muscle
– Fast twitch fibres are able to express
not only higher peak tensions but also
higher forces at higher velocities
Power-velocity relationships during sprint cycling and Wingate Tests
Strength: Maximum force generated by a muscle
Low velocities
High forces
Speed: Maximum velocity
High velocities, low forces
Power = Force (N) x Velocity
Strength x speed
Measuring Force and Contraction Velocity in an Isolated Muscle
You can attach a muscle to a force transducer at one end
and a fulcrum with weight at the other. The weight will
stretch the muscle, and then by stimulating the muscle
electrically you can measure the force and velocity of the
muscle.
The Force Velocity Relationship
When force is high velocity is low and when velocity is high force is low.
This is because with a very high velocity
contraction less myosin heads are attached
to actin at a time because as they pull actin
across they have to release in order to keep
actin sliding across.
Whereas in order to produce a high force
you need more myosin attached to actin
and therefore you cannot contract quickly.
When you calculate power you create
an inverted u shaped curve and your
Maximum power is at about a third of
your maximum contraction velocity
Shape of force velocity curve is
dependent on fibre type in the muscle
– Fast twitch fibres are able to express
not only higher peak tensions but also
higher forces at higher velocities
