Critical Power

Question 1

Poole et al (1998)

Answer 1

• 8 subjects cycling either at CP or 5% above CP until exhaustion
• CP group the exercise had to be terminated by the practitioner
• CP+5% group reached exhaustion after about 20 minutes
• Only 16W difference between groups
• Increase lactate in CP group

Question 2

Jones et al (2008)

Answer 2

• Knee extensor exercise in MRI
• Exercise either 10% above or below CP
• -10% CP, exercise was terminated by practitioner
• 10% above CP reach exhaustion in about 12 mins
• Only 4W difference between group (18/22)
• Change in PCr, muscle pH and Pi in +10% group

Question 3

Florence and Weir (1997)

Answer 3

• Amaeutur entrants of the NY marathon
• CV explained 76% of completion time
• Compared to 51% by Vo2max and 21% by VT

Question 4

Jones et al (2006)

Answer 4

• Andrew Jones - Paula Radcliffe’s physiologist
• Radcliffe’s Vo2max did not change between 1992 and 2003
• However sub-maximal markers such as Vo2, LT increased over than time

Question 5

Determining CP - Hoosh et al (1990)

Answer 5

• Bouts to exhaustion between 1 and 10 mins
• 2 bouts per day on consecutive days
• Good agreement that 1 bout on consecutive days is good enough to calculate CP - as long as bouts differ by >5 mins

Question 6

Determining CP - Bishop and Jenkins (1995)

Answer 6

• 5 familiarisation trials
• Subjects split into 2 groups; 1 group day 1 trial on 3 days and other group did 3 trials on 1 day
• No difference between groups for estimation of CP and W’
• You can use a 1 day protocol, however athletes need to be familiarised

Question 7

Vanhatello et al (2007)

Answer 7

• 3 min all-out test to deplete W’
• When W’ is depleted, end power = CP
• At no point can power increase throughout 3 mins period
• A 3 min test can be used to determine W’ and CP

Question 8

Burnley et al (2007)

Answer 8

• Coefficient of variation of end power = 3%
• Coefficient of variation in normal multiple trial estimates = 6%
• 3 min all-out test more appropriate for determining CP
• 3-min test also gives you Vo2max

Question 9

Training the CP - Poole et al (1990)

Answer 9

• 3 days per week for 7 weeks
• 10 x 2min at 105% CP
• Significantly increases CP (8%) but not W’

Question 10

Training the CP - Jenkins (2002)

Answer 10

• 3 days per week for 8 weeks
• 30 mins at CP (week 1-5) - 35 mins at CP (week 6,7), 40 mins at CP (week 8)
• Power output significantly increased during training
• Significant increases in CP (30%) but not W’

Question 11

Training the CP - Vanhatello et al (2008)

Answer 11

• 3 days per week fro 4 weeks
• 2 sessions per week = 6x5min at 105% CP; 1 session per week = 10x2 min at 105% CP (designed to expand W’)
• 10% increase in CP, no increase in W’

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Question 12

Training the CP - Jenkins and Quigley, (1993)

Answer 12

• 3 days per week for 8 weeks
• 5x1min all out with 5 min recovery between
• No change in CP but 49% increase in W’

Question 13

Miura et al (1999)

Answer 13

• Double-blind randomised cross-over trials
• 6 weeks washout
• Pre and post creatine supplementation
• 20g per day for 5 days
• Increase W’ (25%) but not CP