Warm up: Muscle temp and performance

Question 1

Briefly describe the following relationships:
force - velocity 
power - velocity 
efficiency - velocity 
rate of energy utalisation - velocity

Answer 1

as velocity increase the amount of force produced decreases

as velocity increases the power produced increases until around 30% vMax and then power falls again

similar for efficiency

as velocity increases the rate of energy utilisation increases until it plateus at a maximum rate

Question 2

describe the effect of temperature on the force velocity relationship

and explain the underlying mechanism of this

Answer 2

as temperature increases the curve shifts to the right

so can produce a higher maximum speed of contraction

this is because higher temp. = better enzyme activity/faster ATP hydrolysis = faster cross bridge cycling

Question 3

describe the methods of the study into the effect of temperature on performance

and what were the findings

Answer 3

performing a windgate test to determine force and power output

control
cold bath before test
hot bath before test

peak power = warm>control>cold

but power output was the same at the end of the test for all conditions
so warm muscles also = faster fatigue

Question 4

describe the velocity dependence of the effects of increased temperature on muscle performance

Answer 4

higher temperatures = higher power output for a given velocity

however the benefits of this are seen more profoundly at higher velocities (pedal cadence)

this is because at higher velocities there is more dependence on cross bridge turn over

best effects were seen when cycling at cadences similar to cadence of elite level cylists so good

Question 5

what are the mechanisms behind the increased power output at higher temperatures and what evidence supports this

in which fibre type is this more pronounced

Answer 5

faster rate of ATP turnover because of enhancement of enzymatic processes

25-30% increase in the rate of Pcr utalisation and glycolysis

rate of increase was the same in both fibre types

Question 6

how much of an increase in power output can you get for a 1 degree increase in muscle temp

Answer 6

4-10%

Question 7

how can the call room period potentially lead to a reduced performance in athletes

Answer 7

have to be held for around 15 mins post warm up

muscle temp falls by 1 degree in 15-30mins

so could be as much as a 10% reduction in power output

Question 8

describe the study looking into muscle temp drop reduction to improve sprint cycling performance

what were the findings

Answer 8

thermal heat trousers developed

control
insulation of trousers only
insulation + heating elements (45 degrees)

worn for 15mins post standard sprint cycle warm up

lowest heat loss with insulation + heating, was less than 1 degree

power output:
insulation + heat>insulation>control
overall insulation + heat = 140w increase / 10% increase

Question 9

how does the velodrome environment add an added challenge to heat control

Answer 9

heated to 28 degrees to reduce drag and allow faster times

can increase thermal stress on cyclists

Question 10

how do British Cycling attempt to overcome the challenges the velodrome enviroment

Answer 10

also ear ice vests and cold towels around the necks to keep core temperature down whilst keeping muscle temp up

Question 11

what is the golden hour in a cycling competition

Answer 11

time between rounds
have to fit in cool down, rest and warm up in this time

optimum strategy needs to be developed

Question 12

explain the study looking to optomise muscle temperature in track and field events and its findings

Answer 12

30 min outside warm up at temperatures of 0-15 degrees

rest: 36 at 3cm 33 at 1cm
15mins: 38 at 3cm still 33 at 1cm

30min: same as 15 mins
no further benefit of doing extended warm up

Question 13

describe the methods of the hot pants trial in outdoor athletes

what were the findings

Answer 13

normal warm up done, 3cm muscle temp measured

control (normal tracksuit)
tracksuit then put hot pants on
warm up in hot pants and keep on

hot pants during warm up saw greatest increase in muscle temp
muscle temp was also maintained until event started

control warm up only saw a slight increase in muscle temp so was no real benefit

Question 14

what is the the barrier to implementation of the findings of the benefit of wearing hot pants for track athletes

Answer 14

no electrical devices are allowed in the cool room

Question 15

from a practical persepective, what must practioners consider when planning warm ups other than increasing muscle temperature

Answer 15

balancing this with the development of fatigue bc fatigue will decrease peak power outputs and so attenuate the benefits or warmer muscles

experimental warm up (less intense and shorter duration) vs normal track cylcing warm up
experimental = better power output on 30s windgate test
also better peak active twitch torque

Question 16

what is the effect of increased muscle temperature on the efficiency of muscle contraction

what theory has been put forward to attempt to explain in

Answer 16

at low cadences it decreases efficiency

however at higher cadences, representative of elite cycling it increases efficiency

it is thought that at higher temperatures cross bridge cycling is innapropriatly fast for the slow cadence but this fast turnover is appropriate and beneficial for faster cadences