2005 pan american sports organization talk on individual pursuit
DESCRIPTION
Pan American Sports Organization International Coaching Seminar, hosted by USA Cycling on behalf of the United States Olympic Committee, Colorado Springs, COTRANSCRIPT
The individual pursuit: demands and preparation
Andrew R. Coggan, Ph.D.
The individual pursuit:
a deceptively simple event favoring specialists who possess superior aerobic fitness coupled with a high anaerobic capacity, excellent aerodynamics,
and specific technical skills.
The pursuit performance ‘teeter-totter’
Neuromuscular power
Anaerobic capacity
Aerobic power
Factors
Start
Line
PacingTec
hnica
l Factors
Rolling resistance/chain friction
Inertia/kinetic energy
Aerodynamic drag
Phys
ical
Faster F
aste
rFactors
Phys
iolo
gica
l
Faster or Slower
Physical factors
The pursuit performance ‘teeter-totter’
Neuromuscular power
Anaerobic capacity
Aerobic power
Factors
Start
Line
PacingTec
hnica
l Factors
Rolling resistance/chain friction
Inertia/kinetic energy
Aerodynamic drag
Phys
ical
Faster F
aste
rFactors
Phys
iolo
gica
l
Faster or Slower
PTOT = (PAT + PKE + PRR + PWB + PPE)/Ec
PTOT = (0.5ρVa2Vg(CdA + Fw) + 0.5(mt + I/r2)(Vgf
2 - Vgi2)/(tf - ti) + VgCrrmtgCOS(TAN-
1(Gr)) + Vg(0.091+0.0087Vg) + VgmtgSIN(TAN-1(Gr)))/Ec
Where: PTOT = total power required (W) mt= total mass of bike+rider system (kg)
PAT = power required to overcome total aerodynamic drag (W) I = moment of inertia of wheels (kgm2)
PKE = power required to change kinetic energy (W) r = outside radius of tire (m)
PRR = power required to overcome rolling resistance (W) Vgf = final ground velocity (m/s)
PWB = power required to overcome drag of wheel bearings (W) Vgi = initial ground velocity (m/s)
PPE = power required to change potential energy (W) tf = final time (s)
ρ = air density (kg/m3) ti = initial (s)
Va = air velocity (relative to direction of travel) (m/s) Crr = coefficient of rolling resistance (unitless)
Vg = ground velocity (m/s) g = acceleration due to gravity (9.81 m/s2)
Cd = coefficient of drag (dependent on wind direction) (unitless) Gr = road gradient (unitless)
A = frontal area of bike+rider system (m2) Ec = efficiency of chain drive system (unitless)
FW = wheel rotation factor (expressed as incremental frontal area) (m2)
Mathematical model of the physics of cycling
(Martin, Milliken, Cobb, McFadden, and Coggan. J Appl Biomech 14:276-291, 1998)
Validation of modelunder steady-state conditions
(Martin, Milliken, Cobb, McFadden, and Coggan. J Appl Biomech 14:276-291, 1998)
Validation of modelunder non-steady-state conditions
(Martin, Gardner, Barras, and Martin, unpublished observations)
Measured power
Measured speed
Model-predicted speed
Nominal characteristics of world class pursuiters used in modeling
• Height = 180 cm
• Weight = 75 kg
• CdA = 0.209 m2
• Pursuit power = 540 W
• 4 km time = 4 min 25 s
• Height = 170 cm
• Weight = 65 kg
• CdA = 0.197 m2
• Pursuit power = 415 W
• 3 km time = 3 min 35 s
Male Female
• Weight of bicycle, etc. = 9.0 kg
• CRR = 0.002 (i.e., wood track)
• Air density = 1.185 g/L
Absolute and relative power requirementsof world class pursuit performance
0
100
200
300
400
500
600
Male (4 km) Female (3 km)
Po
we
r (W
)
Aerodynamic drag Kinetic energy Rolling resistance Drivetrain friction
86%
84%
7%
9%
5%
5%
2%
2%
Time savings resulting from 5% changes in:
Factor 4 km 3 km
Efficiency of chain (Ec)
0.1 s (0.05%) 0.1 s (0.05%)
Rolling resistance (CRR)
0.2 s (0.1%) 0.2 s (0.1%)
Total mass (mt)
0.6 s (0.3%) 0.6 s (0.3%)
Aerodynamic drag (CdA) 4.1 s (1.5% ) 3.1 s (1.4% )
Aerodynamics: the devil is in the details!
Field testing using a powermeter to determine aerodynamic drag characteristics (CdA)
0
100
200
300
400
0 5 10 15
Speed (m/s)
Pow
er (
W)
Westbound Eastbound line of best fit
Y = 3.67X + 0.1344X3
R2 = 0.998
CdA = 0.226 +/- 0.004 m2
CRR = 0.0046 +/- 0.0003
Technical factors
The pursuit performance ‘teeter-totter’
Neuromuscular power
Anaerobic capacity
Aerobic power
Factors
Start
Line
PacingTec
hnica
l Factors
Rolling resistance/chain friction
Inertia/kinetic energy
Aerodynamic drag
Phys
ical
Faster F
aste
rFactors
Phys
iolo
gica
l
Faster or Slower
Time savings resulting from improvements in:
Factor 4 km 3 km
Starting technique (negligible) (negligible)
Path on track (20 cm up from black line)
1.3 s (0.5%) 1.1 s (0.5%)
Pacing strategy (potentially large) (potentially large)
2005 World Championships - 3 km pursuit
70
72
74
76
78
80
82
84
86
1 2 3
Kilometer split
Tim
e (s
econ
ds)
Effect of pacing on 3 km pursuit performance
0
100
200
300
400
500
600
700
800
900
1000
0 30 60 90 120 150 180 210 240
Time (seconds)
Po
we
r (W
)
0
2
4
6
8
10
12
14
16
Sp
eed
(m
/s)
Qualifying power Final power Qualifying speed Final speed
Effect of pacing on 3 km pursuit performancewhen overall average power is equivalent
Average = 411 W
Average = 408 W
Time = 3:53.4
Time = 3:51.4
Coggan’s #1 rule of pursuiting:
Don’t go out too hard!
Don’t go out too hard!
Don’t go out too hard!
Don’t go out too hard!
Physiological factors
The pursuit performance ‘teeter-totter’
Neuromuscular power
Anaerobic capacity
Aerobic power
Factors
Start
Line
PacingTec
hnica
l Factors
Rolling resistance/chain friction
Inertia/kinetic energy
Aerodynamic drag
Phys
ical
Faster F
aste
rFactors
Phys
iolo
gica
l
Faster or Slower
The individual pursuit: a predominantly aerobic event
4 km
3 km
Energy demands expressed in O2 equivalents
Power-VO2 relationship (efficiency)
Efficiency = 24.1%
0
1
2
3
4
5
0 50 100 150 200 250 300 350 400
Power (W)
VO
2 (L
/min
)
Time savings resulting from 5% changes in:
Factor 4 km 3 km
Neuromuscular (anaerobic) power
0.3 s (0.1%) 0.2 s (0.1%)
Anaerobic capacity 0.9 s (0.3%) 0.7 s (0.3%)
Aerobic power 3.8 s (1.4%) 3.0 s (1.4%)
Role of VO2max, anaerobic capacity (MAOD) and aerodynamic drag characteristics (CdA) in determining
3 km pursuit performance
0
100
200
300
400
500
600
700
800
900
0 30 60 90 120 150 180 210 240
Time (seconds)
Pow
er (W
)
Rider A Rider B
Maximal aerobic
VO2max = 4.47 L/min
Efficiency = 24.1%
Est. MAOD = 3.36 L
Ave. power = 397 W
CdA = 0.214 m2
3 km time = 3:47.3
Total
80%
20%
Rider A
0
100
200
300
400
500
600
700
800
900
0 30 60 90 120 150 180 210 240
Time (seconds)
Pow
er (W
)
0
100
200
300
400
500
600
700
800
900
0 30 60 90 120 150 180 210 240
Time (seconds)
Po
we
r (W
)
Role of VO2max, anaerobic capacity (MAOD) and aerodynamic drag characteristics (CdA) in determining
3 km pursuit performanceRider A Rider B
VO2max = 4.20 L/min
Efficiency = 23.9%
Est. MAOD = 5.27 L
Ave. power = 411 W
CdA = 0.236 m2
3 km time = 3:49.7
Total
Maximal aerobic72%
28%
Maximal aerobic
VO2max = 4.47 L/min
G.E. = 24.1%
Est. MAOD = 3.36 L
Ave. power = 397 W
CdA = 0.214 m2
3 km time = 3:47.3
Total
80%
20%
Rider A Rider B
Preparation
Level 1 2 3 4 5 6 7
Active recovery
EnduranceTempo or
fartlekLactate
thresholdVO2max Anaerobic
capacity
Neuro-muscular
power
Power ( % of maximal steady
state)<55% 56-75% 76-90% 91-105% 106-120% 121-150% >151%
Muscle enzymes
++ +++ ++++ ++ +
Lactate threshold
++ +++ ++++ ++ +
Capillaries + ++ +++ ++++ +
Plasma volume + ++ +++ ++++ +
Stroke volume & maximal
cardiac output+ ++ +++ ++++ +
VO2max + ++ +++ ++++ +
Anaerobic capacity (MAOD)
+ +++ +
Neuromuscular power
+ +++
Expected physiological adaptationsas a function of training intensity
0
10
20
30
40
50
60
70
80
90
100
40 50 60 70 80 90 100 110 120 130 140 150
Exercise intensity (% of maximal steady state power)
Arb
itra
ry u
nit
s
L1 L2 L3 L4 L5 L6
Physiological strainOverall training effect
(increase in aerobic fitness)
Max. volume
Proposed relationship between training intensity and overall aerobic training effect
0
10
20
30
40
50
60
70
80
90
100
Month
Tra
inin
g v
olu
me
(h/m
o)
Training volume (hours/month)
LT focus (off-season “build”)
VO2max focus (road racing season)
Pursuit-specific training R&R
Day Training
Monday 1 h 30 min recovery ride
Tuesday 2 h w/ 2 x 20 min @ TT effort
Wednesday 2 h 30 min group ride at moderate intensity
Thursday 2 h w/ 2 x 20 min @ TT effort
Friday 1 h 30 min recovery ride
Saturday 4 h hard group ride
Sunday 3 h 15 min group ride at moderate intensity
Typical week during LT focus
Typical week during VO2max focus
Day Training
Monday 1 h 15 min recovery ride
Tuesday 1 h 30 min w/ 6 x 5 min at 90+% of VO2max
Wednesday 2 h at moderate intensity
Thursday 1 h 30 min w/ 6 x 5 min at 90+% of VO2max
Friday 1 h 15 h recovery ride
Saturday Race or tempo ride
Sunday Race or hard group ride
Day Training
Monday 1 h 30 min w/ 4 x 500 m flying and 10 standing starts
TuesdayAM: 1 h 30 min w/ 4 x 4 km flying in team pursuit
formation
PM: 1 h 45 min recovery ride (road)
WednesdayAM: 1 h w/ 1 x 333.3 m standing plus 3 x 1 km
standing
PM: 2 h recovery ride (road)
ThursdayAM: 1 h 30 min w/ 4 x 4 km flying in team pursuit
formation
PM: 30 min recovery ride (rollers)
FridayAM: 2 h recovery ride (road)
PM: 1 h 45 min track racing session (keirin heat, keirn final, prime race, points race)
Saturday 1 h 30 min w/ 3 x 1 km flying and 4 x 500 m flying
Sunday Off
Typical week during pursuit-specific training
0
20
40
60
80
100
120
140
160
180
200
Date
CT
L o
r A
TL
(T
SS
/d)
-100-80-60-40-20020406080100
TS
B (
TS
S/d
)
Acute training load Chronic training load Training stess balance
Use of powermeter data to manage training and plan peak performance
A happy ending!