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Torque and Power-Velocity Relationships in Cycling: Relevance to Track Sprint Performance in World-Class Cyclists

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Torque and Power-Velocity Relationships in Cycling: Relevance to Track Sprint Performance in World-Class Cyclists

Abstract and Figures

The aims of the present study were both to describe anthropometrics and cycling power-velocity characteristics in top-level track sprinters, and to test the hypothesis that these variables would represent interesting predictors of the 200 m track sprint cycling performance. Twelve elite cyclists volunteered to perform a torque-velocity test on a calibrated cycle ergometer, after the measurement of their lean leg volume (LLV) and frontal surface area (A(p)), in order to draw torque- and power-velocity relationships, and to evaluate the maximal power (P(max)), and both the optimal pedalling rate (f(opt)) and torque (T(opt)) at which P (max) is reached. The 200 m performances--i.e. velocity (V200) and pedalling rate (f 200)--were measured during international events (REC) and in the 2002 French Track Cycling Championships (NAT). P(max), f(opt), and T(opt) were respectively 1600 +/- 116 W, 129.8 +/- 4.7 rpm and 118.5 +/- 9.8 N . m. P(max) was strongly correlated with T(opt) (p < 0.001), which was correlated with LLV (p < 0.01). V200 was related to P(max) normalized by A(p) (p < or = 0.05) and also to f(opt) (p < 0.01) for REC and NAT. f 200 (155.2 +/- 3, REC; 149 +/- 4.3, NAT) were significantly higher than f(opt) (p < 0.001). These findings demonstrated that, in this population of world-class track cyclists, the optimization of the ratio between P(max) and A(p) represents a key factor of 200 m performance. Concerning the major role also played by f(opt), it is assumed that, considering high values of f 200, sprinters with a high value of optimal pedalling rate (i.e. lower f200-f(opt) difference) could be theoretically in better conditions to maximize their power output during the race and hence performance.
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Introduction
The 200 m flying start is the qualifying race for the “Match
Sprint” competition. “Match Sprint” is considered to involve the
most explosive effort amongst high-performance track-cycling
events. It can be said to include three phases: an acceleration
phase (before the start of timed portion of the flying 200 m), a
maximal velocity phase, and a deceleration phase (the last both
included between the start and finish lines of the 200 m). Out-
standing national and international performances are commonly
completed within 10 11 s. This has not been significantly im-
proved over the last twenty years [40]. Also, in contrast with road
cycling, the absence of any gear system means that the constant
gear ratio chosen before the race directly influences the mean
Abstract
The aims of the present study were both to describe anthropo-
metrics and cycling power-velocity characteristics in top-level
track sprinters, and to test the hypothesis that these variables
would represent interesting predictors of the 200 m track sprint
cycling performance. Twelve elite cyclists volunteered to per-
form a torque-velocity test on a calibrated cycle ergometer, after
the measurement of their lean leg volume (LLV) and frontal sur-
face area (A
p
), in order to draw torque- and power-velocity rela-
tionships, and to evaluate the maximal power (P
max
), and both
the optimal pedalling rate (f
opt
) and torque (T
opt
) at which P
max
is
reached. The 200 m performances i.e. velocity (V
200
) and pedal-
ling rate (f
200
) were measured during international events
(REC) and in the 2002 French Track Cycling Championships
(NAT). P
max
, f
opt
, and T
opt
were respectively 1600 ± 116 W,
129.8 ± 4.7 rpm and 118.5 ± 9.8 N · m. P
max
was strongly correlated
with T
opt
(p < 0.001), which was correlated with LLV (p < 0.01).
V
200
was related to P
max
normalized by A
p
(p 0.05) and also to
f
opt
(p < 0.01) for REC and NAT. f
200
(155.2 ± 3, REC; 149 ± 4.3,
NAT) were significantly higher than f
opt
(p < 0.001). These find-
ings demonstrated that, in this population of world-class track
cyclists, the optimization of the ratio between P
max
and A
p
repre-
sents a key factor of 200 m performance. Concerning the major
role also played by f
opt
, it is assumed that, considering high val-
ues of f
200
, sprinters with a high value of optimal pedalling rate
(i.e. lower f
200
–f
opt
difference) could be theoretically in better
conditions to maximize their power output during the race and
hence performance.
Key words
Elite sprint cycling · 200 m flying start · maximal power (P
max
optimal pedalling rate (f
opt
) · projected frontal area (A
p
)
Training & Testing
739
Affiliation
1
Laboratoire de Biomécanique et de Modélisation Humaine (Equipe Physiologie de l’Exercice) Faculté de
Médecine Lyon-Sud, Oullins cedex, France
2
Laboratoire de Physiologie – Unité PPEH, CHU St-Jean-Bonnefonds, Saint-Etienne cedex 2, France
3
Laboratoire de Physiologie de l’Exercice (BAPS), Gabriel Montpied Hospital, Clermont-Ferrand cedex 1,
France
4
Centre de Recherche et d’Innovation sur le Sport (CRIS), Université Claude Bernard – Lyon I, Villeurbanne
cedex, France
Correspondence
S. Dorel · Laboratoire de Biomécanique et de Modélisation Humaine (Equipe Physiologie de l’Exercise) –
Faculté de Médecine Lyon-Sud · BP 12 · 69921 Oullins cedex · France · Phone: + 33478 863135 ·
Fax: + 33 478 86 3135 · E-mail: Dorel77@wanadoo.fr or Sylvain.Dorel@univ-lyon1.fr
Accepted after revision: September 30, 2004
Bibliography
Int J Sports Med 2005; 26: 739 746 © Georg Thieme Verlag KG · Stuttgart · New York ·
DOI 10.1055/s-2004-830493 · Published online January 24, 2005 ·
ISSN 0172-4622
S. Dorel
1,2
C. A. Hautier
4
O. Rambaud
1
D. Rouffet
4
E. Van Praagh
3
J.-R. Lacour
1
M. Bourdin
1
Torque and Power-Velocity Relationships in Cycling:
Relevance to Track Sprint Performance in
World-Class Cyclists
pedalling rate sustained in the sprint (f
200
). Retrospective anal-
ysis of the ten best peak performances obtained during the pre-
ceding 5 years’ world championships and world cup races ena-
bles us to calculate a strongly significant relationship between
performance in the 200 m time trial and the final competition
ranking (r = 0,95; p < 0.001). However, little data, to our knowl-
edge, is available concerning track sprint cycling. An anthropo-
metric analysis by McLean et al. [31] suggested a trend for corre-
lation of thigh girth with 200 m sprint performance. The authors
hypothesized that absolute strength may contribute to success in
this event. Thus, in this explosive event, muscle anaerobic me-
tabolism [20], neuromuscular and mechanical factors, including
maximal force and/or power of the lower limbs [43], may con-
tribute to final performance.
These muscle power characteristics demonstrated during cycling
can be accurately measured on a cycle ergometer, using the well
known torque-velocity test [1,19, 27, 28, 32,39,41]. The linear re-
lationship obtained between torque and pedalling rate enables
assessment of f
0
and T
0
, which have the dimensions of maximal
pedalling rate at the zero torque axis and the torque correspond-
ing to a zero pedalling rate, respectively (Fig.1). Maximal power
generation is described by a polynomial power-velocity relation-
ship [11,18, 28, 39]. Power output reaches a maximum value
(P
max
) at the optimal cycling rate (f
opt
). For example, sprint run-
ning and high jump performances have been demonstrated to
be correlated with P
max
[33,44] and sometimes also with f
opt
[16]. It is noteworthy that information concerning both power
and velocity data in elite track sprint cyclists is not well docu-
mented, neither is information concerning the possible relation-
ships between these factors and performance.
From the mechanical point of view, considering several endur-
ance cycling power equations [2, 5, 8,10,26,35,36] and the high
speeds achieved during sprint cycling (> 18 m · s
–1
), air resistance
(R
a
) represents the main resistive force acting on the rider + bi-
cycle system (> 90%). For a standardized environment, R
a
still de-
pends on speed (V) and two individual biomechanical-anthropo-
metric factors: the drag coefficient (C
d
) and the frontal area of the
rider + bicycle (A
p
) (i.e. R
a
=0.5ρA
p
C
d
V
2
, where ρ is the air den-
sity). Measurement of individual A
p
by photographic methods,
as proposed in some recent studies [5,17,37], might help a better
understanding of the mechanical linkage between power output
and performance (i.e. cycling speed).
The present study describes anthropometrics and the torque-
and power-velocity relationships in world-level sprint track cy-
clists, providing data for future comparative studies. The purpose
was to investigate whether these anthropometric and cycling
power characteristics were related to flying-start 200 m sprint
performance in this population. Finally, the present investigation
tested the hypothesis that f
200
attained during the 200 m is sim-
ilar or close to f
opt
and discussed how values of the latter would
influence performance.
Materials and Methods
Subjects and anthropometry
Twelve male elite cyclists volunteered to participate in the study.
Five were professional track cyclists, including three winners of
World or Olympic championships (F, H, K). All were competing
in national and international-level track races. Anthropometric
measurements are reported in Table 1. Four skinfold thicknesses
were measured to estimate the percentage of body fat (BF), using
the equations of Durnin and Rahaman [13]. Lean leg volume
(LLV) was calculated by anthropometry using Jones and Pear-
son’s technique [22]. The projected frontal area (A
p
) of ten of the
twelve cyclists (riding their own competition bicycles, clothes,
and helmet) was determined in the position they commonly
used during competition: i.e. from partially to fully bent-over
torso position (parallel with the ground), with the hands on the
drops portion of the handlebars and elbows more or less flexed.
Subjects were asked to maintain their head in the same position
as used during the race (Fig. 2). A
p
results were obtained accord-
ing to the method used by Heil et al. [17]. Digital photographs
were taken of each the participant sitting on his bicycle with a
square surface of known area at their side. The area enclosed by
Pedaling rate (rpm)
Power (W)
P
max
f
opt
R = 0,9865
2
R = 0,9911
2
R = 0,9687
2
R = 0,9538
2
0
50
100
150
200
250
300
0 50 100 150 200 250 300
2000
1750
1500
1250
1000
750
500
250
0
0
50 100 150 200 250 300
Pedaling rate (rpm)
Torque
(
Nm
)
.
f
0
T
0
ab
Fig.1a and b Torque (a) and power-velocity (b) relationships of two
athletes, F and K, fitted by average downstroke values obtained from
three sprints of 5-s duration. Determination of maximal power (P
max
),
optimal cycling rate (f
opt
), maximal cycling rate (f
0
), and maximal tor-
que (T
0
). F: filled circles; K: open circles.
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
740
the cyclist and his bicycle (including wheel spokes and the areas
between the lower limbs and the bicycle as well as that between
the upper limbs and the trunk) was delimited using a computer-
based image analysis software application (Scion Image Beta
4.02; Scion Corporation, Frederick, MD). The actual A
p
(in m
2
)
was determined by dividing this enclosed area by the area of
the calibration image and then multiplying by the known area
of the calibration frame (0.16m
2
). The study was performed dur-
ing racing season, one month before the National Track Cycling
Championships. The testing procedures were explained to the
participants before they gave their informed consent.
Torque-velocity test (T-V test)
After a 5-min warm-up, the cyclists performed three maximal
cycling sprints of 5-s duration, interspersed with 5-min rest peri-
ods according to the protocol proposed by Arsac et al. [1]. Each
sprint was performed against a specific force applied to the fric-
tion belt: 0.3, 0.6, or 0.9 N·kg
–1
body mass. The corresponding
friction torques were 0.287, 0.573, and 0.859 N · m·kg
–1
body
mass, respectively. The cycle ergometer (Monark 818E, Stock-
holm, Sweden) was equipped with the same handlebar and ped-
als as used during track sprint cycling. Saddle height, handlebar
height, and stem length were set to match the usual position of
the participants. Since it is well established that crank length in-
fluences the optimal pedalling rate [27], a standard crank length
of 170 mm (similar or close to the crank length used in the field,
i.e. 165 or 170 mm) was chosen to provide optimal test condi-
tions compared with field conditions. Subjects were told to re-
main seated on the saddle throughout the test, and were vigor-
ously encouraged to produce the highest acceleration possible.
Table 1 Individual anthropometric and best flying-start 200 m performance characteristics (n = 12)
Subject Age (yr) BM (kg) H (cm) BF (%) LLV (L) A
p
(m
2
)T
200
(s) % W
rec
(%)
A 22 80 182 8.6 10.03 0.533 10.23 96.5
B 22 83 172 12.3 9.99 0.512 10.35 95.3
C 21 78 178 10.4 9.62 0.525 10.6 93.1
D 23 92 185 12.6 10.69 0.558 10.81 91.3
E 22 84 185 13.2 11.05 0.536 10.24 96.3
F 29 78 176 11.4 8.19 0.510 10.04 98.3
G 26 88.5 181 11.9 10.7 0.537 10.44 94.5
H 27 78 183 10 10.07 10.33 95.5
I 19 86 178 15.6 9.49 0.535 10.38 95.1
J 21 76 184 10.2 8.53 0.525 10.91 90.4
K 29 87 182 8.1 11.09 0.538 10.07 98
L 31 85.5 183 11.7 10.85 10.42 94.7
Mean (SD) 24.3 (3.9) 83 (5) 180.8 (3.9) 11.3 (2) 10.03 (0.95) 0.531 (0.014) 10.40 (0.26) 94.9 (2.4)
BM, body mass (kg); H, height (cm); BF, body fat (%); LLV, lean leg volume (L); A
p
, projected frontal area of the cyclist and his bicycle (m
2
); T
200
, time reached during the best
performance in flying-start 200 m (s); %W
rec
, best performance, expressed as a percentage of the world record
Fig. 2 Sample A
p
photograph of a single
subject (A) on his own bicycle in the tradi-
tional body position and with the equipment
used during competition. The square surface
of known area (0.16m
2
) is presented at his
side.
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
741
The technical and mechanical characteristics of the friction-load-
ed cycle ergometer have been previously described [1, 32]. A
strain gauge (200 N, bandwidth 500 Hz) measured the frictional
force. An optical encoder (1969.2 points per meter of displace-
ment or 11815 points per pedal revolution) recorded flywheel
displacement (m = 22.5 kg). Force and displacement signals were
sampled (200 Hz) and stored on a PC via a 12-bit analog-to-digi-
tal interface card (DAS-8, 12 bits, Keithley Metrabyte, Taunton,
MA). First and second order derivatives of the flywheel dis-
placement were calculated to obtain flywheel velocity and ac-
celeration. The external torque produced was calculated as the
sum of the frictional torque (given by the strain gauge) plus the
torque necessary to accelerate the flywheel [14, 23, 32]. The mo-
ment of inertia of the flywheel (I) had been previously deter-
mined using the method of the free deceleration of the flywheel
described by Arsac et al. [1], Lakomy [23], and Martin et al. [28]:
I=0.927kg·m
2
. Power, torque and pedalling rate were averaged
for pedal down-stroke. After computation, the data obtained
from the three sprints were cumulated and used to draw up the
torque- and power-velocity relationships, using linear and quad-
ratic regressions, respectively [11,16,18, 28, 33,41].
Both maximal pedalling rate (f
0
, in rpm) and maximal torque (T
0
,
in N.m) were obtained by extrapolation. They correspond to the
intercept of the torque-velocity curve with the velocity and
torque axes, respectively. Maximal power (P
max
, in W) was iden-
tified as the apex of the power-velocity relationship. Optimal
pedalling rate (f
opt
) was the pedalling rate at which P
max
occurred.
Consecutive calculation considered the derivative of the equa-
tion of the power-velocity relationship to be equal to zero at this
point. The value of the torque at which P
max
occurred – i.e. opti-
mal torque (T
opt
) was deduced from values of P
max
and f
opt
. The
cycling torque-velocity and power-velocity relationships for two
typical athletes (F and K) are presented in Fig.1. All maximal
power values (P
max
) were normalized for body mass (W · kg
–1
)
and for A
p
(W·m
–2
).
Flying-start 200 m cycling performances
Individual 200 m records (REC) were initially collected, all of
which had been achieved on indoor tracks over the last three
years. Each subject used the same competitive equipment and
bicycle (Look KG396, France). The testing protocol was carried
out during the competitive period. Different environmental as-
pects such as altitude and track composition are known to influ-
ence individual cycling performances [2, 40]. For this reason, per-
formances completed by the athletes during the French Track Cy-
cling Championships (NAT) i.e. with the same training level
and the same environmental conditions (altitude: sea level;
250 m outdoor wooden track, with constant wind speed) were
also analysed in the current study. These track test performances
were organized one month after the anthropometric and T-V test
measurements. 200 m sprint cycling performances were meas-
ured with an electronic timer (accuracy ± 0.001 s) by federation
officials, and corresponding mean velocities (V
200
,inm·s
–1
) were
calculated. The gear ratio determined the distance the bike trav-
elled in one pedal revolution (D
R
, in m). Considering the gear ra-
tio used for each performance and a constant wheel diameter,
the mean pedalling frequency (f
200
, in rpm) was calculated using
the following equation: f
200
=(V
200
·60)/D
R
.
Statistical analysis
All data were analyzed with StatView software (version 5.0).
They are expressed as means ± standard deviation (SD). Linear
torque-velocity and quadratic power-velocity regression models
were fitted by the least square method. Pearson product-mo-
ment correlation coefficients were calculated to determine
whether relationships between anthropometric data (LLV, A
p
),
T-V test data (f
0
, f
opt
,T
0
,T
opt
,P
max
) and 200 m track cycling per-
formances (V
200
, f
200
) were significant. Significant relationships
between variables were examined by linear and multiple regres-
sion analysis. Paired t-tests were used to study the differences in
cycling rates between the T-V test and track sprint cycling values
(f
opt
and f
200,
respectively). The level of significance was set at
p 0.05.
Results
Torque-velocity test
In the whole group, the torque- and power-velocity relationships
were described best by linear and quadratic models, respectively.
The determination coefficients averaged 0.981 0.010) and
0.957 0.015), respectively. Values of maximal and optimal cy-
cling rates (f
0
and f
opt
), maximal and optimal torques (T
0
and T
opt
),
and maximal absolute and relative power (P
max
) are shown in
Table 2.T
0
and T
opt
were significantly related to lean leg volume
(LLV) (r = 0.77, p < 0.01 and r = 0.69, p < 0.01). P
max
was signifi-
cantly correlated with T
0
and T
opt
(r = 0.92, p < 0.001 and r = 0.91,
p < 0.001; Fig. 3) but not with f
0
or f
opt
.
A
p
and 200 m track cycling performances
Values of A
p
are presented in Table 1.A
p
was significantly related
to the body mass (BM, r = 0.76, p < 0.01) and the height (H,
r = 0.75, p < 0.01). A
p
was also significantly correlated with LLV
(r = 0.66, p < 0.05).
Individual values of velocity and cycling rate obtained during
REC and NAT are presented in Table 2. NAT performances were
3.5% lower than REC, but both performances were strongly cor-
related (r = 0.90; p < 0.001). These performances represent re-
spectively 91.6% and 94.9 % of the current world record (set at
high altitude: 9.865 s 20.27 m ·s
–1
; Bogotta, 1995). V
200
was
strongly correlated with f
200
for both REC and NAT (r = 0.87,
p < 0.001 and r = 0.93, p < 0.001, respectively).
Relationships with 200 m performances
No significant relationships were found between V
200
and P
max
(in W or W·kg
–1
) on linear regression analysis. Significant rela-
tionships were observed in V
200
and P
max
/A
p
for REC and NAT
(r = 0.75, p = 0.01; r = 0.63, p = 0.05, respectively; Fig. 4). A signifi-
cant relationship was observed between V
200
and f
opt
(r = 0.77,
p < 0.01 for both performances; Fig. 5). On the multiple regres-
sion analysis, the highest V
200
coefficient was obtained when
both independent variables f
opt
and P
max
/A
p
were taken into ac-
count (REC: r = 0.96, p < 0.0001; NAT: r = 0.87, p < 0.01). None of
the anthropometric variables were directly correlated with V
200
.
f
200
was higher than f
opt
by 19.2 % for REC and by 14.8% for NAT
(p < 0.001, Table 2).
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
742
Discussion
Torque-velocity relationships in world-class sprint cyclists
To the best of our knowledge, torque and power-velocity rela-
tionships of an elite track sprint cyclist group have not previously
been reported in the literature. Previous investigations have re-
ported maximum P
max
values of between 17.1 W · kg
–1
in elite
power athletes [7, 44] and 20.2 W· kg
–1
in one elite track cyclist
[28]. This last figure falls within our present range, which was
from 17.6 to 21.8 W · kg
–1
. Such high P
max
values measured in this
population support the hypothesis put forward by several au-
thors that sprint training background and genetics could be fac-
tors which might determine individual P
max
[1,18, 44]. Addition-
ally, our mean value for f
opt
(129.8 rpm) is higher than previously
reported values of 122 rpm [28]. In the same way, compared to
the few data reported for national-level sprint runners and elite
junior track cyclists (i.e. 247 and 249 rpm, respectively) [44], the
present mean f
0
value (260 rpm) was high. However, this value is
similar to that of the elite track cyclist reported by Martin et al.
(260 rpm) [28] and f
opt
value is slightly lower than values report-
ed by Hintzy et al. (134.3 rpm) [18] and found in our own labora-
tory (138 rpm, unpublished data), in athletes specialized in ex-
plosive-type events and in national-level sprint runners, respec-
Table 2 Individual values of maximal and optimal pedalling rates (f
0
, f
opt
), maximal and optimal torques (T
0
,T
opt
), maximal power (P
max
)
obtained during the T-V test, and 200 m sprint cycling data expressed in terms of individual record (REC) velocity and cycling rate
(V
200
, f
200
) or the mean values attained during national championships (NAT)
Partici-
pants
f
0
(rpm)
f
opt
(rpm)
T
0
(N · m)
T
opt
(N · m)
P
max
(W)
P
max
(W · kg
–1
)
V
200
(REC)
(m ·s
–1
)
f
200
(REC)
(rpm)
V
200
(NAT)
(m · s
–1
)
f
200
(NAT)
(rpm)
A 260 130 241 121 1640 20.5 19.55 157 19.18 154
B 267 133 224 108 1510 18.2 19.32 152 18.71 150.3
C 259 129 220 111 1500 19.2 18.87 154.7 18.42 151
D 247 123 254 127 1635 17.8 18.50 151.7 18.17 142.9
E 257 128 270 137 1830 21.8 19.53 156.9 18.53 148.8
F 282 141 215 107 1580 20.3 19.92 160 19.22 154.4
G 256 127 233 119 1587 17.9 19.16 153.9 18.45 145.1
H 262 131 225 112 1533 19.7 19.36 158.7 18.63 149.6
I 262 130 230 119 1615 18.8 19.27 154.8 18.75 150.6
J 251 123 217 113 1460 19.2 18.33 150.3 17.48 140.4
K 258 130 269 134 1800 20.7 19.86 159.5 18.92 152
L 259 132 230 114 1502 17.6 19.19 154.2 18.48 148.4
Mean (SD) 260.0
(8.6)
129.8
(4.7)
235.7
(19.1)
118.5
(9.8)
1600
(116)
19.3
(1.3)
19.24
(0.48)
155.3***
(3.1)
18.58
(0.46)
149***
(4.3)
*** p < 0.001, f
200
significantly different from f
opt
Fig. 3 The relationship between maximal power (P
max
) and T
opt
mea-
sured by the torque-velocity test (n = 12).
Fig. 4 Relationships between the record velocity (V
200
) of the cyclists
during their best 200 m performance (REC: open circles) and the mean
value attained during the French Track Cycling Championships (NAT:
filled circles) and the maximal power normalized by the frontal area
(P
max
/A
p
), (n = 10).
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
743
tively. The mean T
0
value (235.8 N · m) obtained in the present
study is in agreement with the previously elite track cyclist re-
ported value of 237 Nm [28]. Our range of values for T
0
(215
270 N · m) is similar to the highest values reported by McIntosh
et al. [25] for a track cyclist and a power lifter (i.e 235
287 N·m; calculated from the reported maximal resistance force
data).
According to the linear torque-velocity relationship, f
opt
and T
opt
were equal to 0.5 f
0
and 0.5 T
0
, respectively, for each individual.
Notwithstanding the fact that all these results presented in Table
2 provide data for future comparative studies, the following dis-
cussion will focus only on P
max
and its two components f
opt
and
T
opt
. In contrast to previous studies [1,18], no relationship was
observed between P
max
and f
opt
in this homogenous elite track-
cyclist group. P
max
was better explained by T
opt
(Fig. 3), which
was significantly related to LLV. In agreement with Driss et al.
[12], who suggested T
0
to be a good indicator of maximal
strength, this underlines the possible effect of the strength train-
ing that has been practiced in this group for the last five to ten
years. Comparing the high T
opt
and P
max
values with the compa-
rable f
opt
values to those obtained in other explosive events, it
would suggest that the training program applied in this popula-
tion (specific cycling training and strength conditioning) did not
represent a means of improving optimal pedalling rate. This is
coherent with the hypothesis that the velocity ability (f
opt
) is less
sensitive to the training. This may account as well for the fibre
conversion from type IIb (or IIx) to IIa which could result from
the enhanced strength training program run in this population
[9, 42].
P
max
,A
p
, and 200 m performances
Values of V
200
NAT (18.58 m · s
–1
, outdoor track) compared to V
200
REC (19.24 m·s
–1
, indoor track) confirm the high level of both
training and commitment of the athletes during the test period.
In contrast to our hypothesis and despite the trend, the linear re-
lationship between 200 m performance and P
max
(in W or
W·kg
–1
) was not statistically significant in this elite population
(r ranged from 0.39 to 0.57, and p ranged from 0.207 to 0.054 for
REC and NAT). However, minimizing aerodynamic parameters
(A
p
and C
d
) induces a decrease in the part of mechanical power
wasted in overcoming air resistance. Hence, for a given power
output, this results in an increase of the cycling speed [2,5,
8,26,35 37]. It could therefore be expected that the measure-
ment of these parameters would make sense to the relationship
between power output and cycling speed. The significant rela-
tionship observed between V
200
and P
max
related to A
p
(for REC
and NAT, Fig. 4) supports this expectation. C
d
(the second compo-
nent of the drag area, which is equal to the product of A
p
and C
d
)
was not measured, although it probably also plays a major role in
performance. This represents a limitation in the interpretation of
the results. Further investigations using wind tunnel [37] or free
deceleration techniques [4] may provide more information
about the link between these two aerodynamic parameters,
maximal power, and performance.
The mean value of A
p
(0.531 m
2
) was comparable with the total
A
p
values reported by Heil et al. [17] in road cyclists in compara-
ble positions and is in agreement with the Body A
p
data (0.42 m
2
)
reported by Capelli et al. [5] considering a Bicycle A
p
value of
0.117 0.130 m
2
[17]. The finding that both body mass and height
significantly influenced variation in A
p
which is consistent with
previous studies, confirms the influence of anthropometrics (i.e.
the rider’s size) on aerodynamics and hence on performance [5].
However, in the present population, the significant relationships
also observed between A
p
and LLV and between LLV and T
opt
emphasize the paradox regarding the rider’s size: on the one
hand decreasing to minimize A
p
and on the other hand increas-
ing to improve muscle volume, torque, and hence power output.
Regarding all these parameters, further improvements of the
200 m performance still seem to be possible for some subjects
by increasing P
max
and optimizing, in the same time, the body
fat (which remains slightly higher than values reported for pro-
fessional road cyclists, from 5 to 8 9%, [6,24, 45]) to decrease or
at least maintain A
p
. Other ways to decrease A
p
and/or C
d
would
be to optimize the position on the bicycle [21] and to systemati-
cally use an aerodynamic helmet.
Pedalling rates and 200 m performances
The significant relationship obtained between V
200
and f
200
is
mainly explained by the fact that only three very similar gear ra-
tios were used in this group (i.e. G
R
= 7.32, 7.47, or 7.63 m). The
major finding of the present study was that V
200
was significantly
related to f
opt
in these top-level sprint cyclists (Fig. 5). Although
f
opt
is assumed to be related to explosive training status, to the
best of our knowledge no previous study has assessed the rela-
tionship between this factor and top performance in any sprint
cycling event. According to Vandewalle et al. [44], Sargeant et al.
[39] and Hautier et al. [16] who suggest that f
opt
is related to the
percentage of fast twitch muscle fibres, a higher f
opt
must be ben-
eficial for “all-out” explosive events. Even if f
opt
represents one of
the two components of P
max
, no relationship was found between
these two variables: the multiple regression analysis showed
that these parameters taken together explained 91% and 80% of
the V
200
variation for REC and NAT, respectively. It seems to indi-
cate that having a high f
opt
value is not an advantage regarding
Fig. 5 Relationships between the record velocity (V
200
) of the cyclists
during their best 200 m performance (REC: open circles) and the mean
value attained during the French Track Cycling Championships (NAT:
filled circles) and the optimal cycling rate (f
opt
) measured by the T-V
test (n = 12).
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
744
the absolute value of P
max
and that the influence of f
opt
must be
elucidated independently.
Regarding the specific pedalling conditions on the track (f
200
), the
hypothesis that f
200
was similar to f
opt
was not confirmed, i.e. f
200
being higher by 19.8 % and 14.8% for REC and NAT, respectively.
Moreover, the main finding is that this discrepancy is not equiv-
alent among subjects (range: 13.5 % to 23.3 % for REC). Such an
observation is particularly important as it refers to the power-
velocity relationship. Thus, a previous study by our group dem-
onstrated that during a short (< 5-s) “all-out” exercise the closer
the velocity was to f
opt
, the greater the total work performed [11].
As illustrated in Fig. 6, the maximal value of power produced at
this pedalling rate (Pf
200
) and calculated via the power-velocity
equation, does not represent the same percentage of P
max
among
the subjects. Associated with the fact that only three very similar
gear ratios were used in this group, the f
opt
of the sprinters being
higher and hence made the pedalling rate during the 200 m (f
200
)
closer to that in racing conditions, so their ability was greater to
produce high Pf
200
. This is confirmed by the strong relationship
obtained between the relative Pf
200
(expressed as a percentage
of P
max
) and f
opt
(r = 0.81, p < 0.001 for REC; r = 0.67, p < 0.05 for
NAT).
Hypothesis on the choice of pedalling rate during
the track event
As discussed above, it can be reasonably assumed that using a
higher gear ratio could result in lower pedalling rate and hence
lead to higher power during the race and performance, especially
for individuals presenting low f
opt
values. Additionally, cycling
rates closer to f
opt
may decrease the energy cost of the internal
power used to move the legs [11,15,30], the negative muscle
work [34] and may increase the mechanical efficiency [11, 38].
Furthermore, the capacity of the athletes to resist fatigue
throughout the race (acceleration: > 6-s and timed portion; 10
11-s) should not be neglected in the understanding of the per-
formance. Once more, previous studies clearly demonstrated
that fatigue index during maximal cycling exercise was also de-
creased at lower pedalling velocities (60 and 100 rpm) compared
to higher (120 and 140 rpm) [3, 29].
One question remains: why are f
200
values higher than f
opt
val-
ues? The results of the present study allow asking the question
rather than answering to this one. Firstly, an alternative interpre-
tation is that gears the riders choose allow maximal power to oc-
cur during the acceleration phase. Further studies, currently
underway, will estimate the effect of using higher gear ratios on
global performance and on power production during each specif-
ic phase. Secondly, it should be kept in mind that, historically, the
200 m is usually performed with the gear ratio used in the
“Match Sprint”. During this event, the choice of the gear ratio is
more complex since it depends on other mechanical (great accel-
eration) and tactical factors (opponent reaction).
In conclusion, the main findings of our study that, both P
max
related to A
p
and f
opt
were significant predictors of 200 m per-
formance, indicate that the cycling torque-velocity test as well
as measurement of the frontal area have several applications in
the understanding of the top-level track sprint cycling perform-
ance. Variations in these parameters could be used to character-
ize the general ability of sprinters and/or to test the efficiency of
a specific training program. Additionally, the performance on the
track was characterized by specific high-rate pedalling condi-
tions (f
200
, 150.3 to 160 rpm) compared to f
opt
(123 to 141 rpm).
This difference being far from uniform among subjects, this
could probably account for the important role played by f
opt
on
performance and primarily questioned the adjustment of the
gear ratios to the individual’s power-velocity characteristics. Fur-
ther studies are needed to investigate whether an individualized
gear ratio (i.e. a lower f
200
value, closer to f
opt
) may improve
200 m performance and what impact it could have on the fatigue
process.
Fig. 6a and b Determination of P
f200
(REC) from the power-velocity
relationship of two typical athletes. F (a) and K (b) and from the value
of the mean cycling rate maintained during the 200 m performance
(f
200
). Observe the smaller discrepancy between P
max
and P
f200
for ath-
lete F (f
opt
: 141 rpm, f
200
: 160 rpm) compared with K (f
opt
: 130 rpm, f
200
:
159.5 rpm).
Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
Training & Testing
745
Acknowledgements
A part of the submission has been presented at the 8th Annual
Congress of the European College of Sport Science, Salzburg,
2003.
This study was possible only because of the cooperation of sev-
eral individuals. The authors wish to extend their sincere appre-
ciation to the participants, to Daniel Morelon and Gerard Quin-
tyn, the coaches of the French Federation of Cycling for allowing
us to conduct the tests, to Dr. Ronan Martin, Dr. Carine Bret, Cy-
rille Routier for assistance during the protocol and to Dr. Frédéric
Grappe for material assistance.
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Dorel S et al. Sprint Performance of Elite Track Cyclists Int J Sports Med 2005; 26: 739 746
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The aim was to investigate the effects of a gym-based strength training intervention on biomechanics and intermuscular coordination patterns during short-term maximal cycling. Twelve track sprint cyclists performed 3 × 4 s seated sprints at 135 rpm, interspersed with 2 × 4 s seated sprints at 60 rpm on an isokinetic ergometer, repeating the session 11.6 ± 1.4 weeks later following a training programme that included two gym-based strength training sessions per week. Joint moments were calculated via inverse dynamics, using pedal forces and limb kinematics. EMG activity was measured for 9 lower limb muscles. Track cyclists 'leg strength" increased (7.6 ± 11.9 kg, P = 0.050 and ES = 0.26) following the strength training intervention. This was accompanied by a significant increase in crank power over a complete revolution for sprints at 135 rpm (26.5 ± 36.2 W, P = 0.028 and ES = 0.29). The increase in leg strength and average crank power was associated with a change in biceps femoris muscle activity, indicating that the riders successfully adapted their intermuscular coordination patterns to accommodate the changes in personal constraints to increase crank power.
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The aim of the study was to compare the Force-Velocity profiles of track sprint cyclists obtained in seated and non-seated positions. Athletes were tested on a stationary cycle ergometer for the seated position and on a racing bike at the velodrome for the non-seated position. We modelled torque and power vs. cadence relationships and extracted maximal force (F0), optimal cadence (Copt), maximal power (Pmax), maximal cadence (C0) and Copt/C0 ratio. Torque/power production was larger in the non-seated position for cadences ranging from 20 to 120 rpm, while more torque and power were produced in the seated position at cadences above 160 rpm. The effective pedal force increased by 0.2 times bodyweight at 50 rpm, and the power production increased by 2.5 W. kg-1 at 90 rpm in the non-seated position. Copt (-14 ± 8 rpm, P < 0.05) and C0 (-55 ± 32 rpm, P < 0.05) were lowered, while Pmax (+1.7 ± 1.1 W. kg-1, P < 0.05) and Copt/C0 ratios (+0.07 ± 0.04, P < 0.05) were increased in the non-seated position when compared with the seated position. Our results show that adopting a non-seated position allows sprint cyclists to maximise torque/power production at lower cadences, while torque/power production was maximised at higher cadences when athletes adopted a seated position.
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Purpose: To examine whether the muscle typology of elite and world-class swimmers could discriminate between their best distance event, swimming stroke style, or performance level. Methodology: The muscle carnosine content of 43 male (860 [76] FINA [Fédération Internationale de Natation] points) and 30 female (881 [63] FINA points) swimmers was measured in the soleus and gastrocnemius by proton magnetic resonance spectroscopy and expressed as a carnosine aggregate Z score (CAZ score) to estimate muscle typology. A higher CAZ score is associated with a higher estimated proportion of type II fibers. Swimmers were categorized by their best stroke, distance category (sprinters, 50-100 m; middle distance, 200-400 m; or long distance, 800 m-open water), and performance level (world-class, world top 10, or elite and world top 100 swimmers outside of the world top 10). Results: There was no significant difference in the CAZ score of sprint- (-0.08 [0.55]), middle- (-0.17 [0.70]), or long-distance swimmers (-0.30 [0.75], P = .693). World-class sprint swimmers (all strokes included) had a significantly higher CAZ score (0.37 [0.70]) when compared to elite sprint swimmers (-0.25 [0.61], P = .024, d = 0.94). Breaststroke swimmers (0.69 [0.73]) had a significantly higher CAZ score compared to freestyle (-0.24 [0.54], P < .001, d = 1.46), backstroke (-0.16 [0.47], P = .006, d = 1.42), and butterfly swimmers (-0.39 [0.53], P < .001, d = 1.70). Furthermore, within the cohort of breaststroke swimmers, there was a significant positive correlation between FINA points and CAZ score (r = .728, P = .011); however, this association was not evident in other strokes. Conclusion: While there was no clear association between muscle typology and event distance specialization, world-class sprint swimmers possess a greater estimated proportion of type II fibers compared to elite sprint swimmers, as well as breaststroke swimmers compared to freestyle, backstroke, and butterfly swimmers.
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This investigation sought to determine if cycling power could be accurately modeled. A mathematical model of cycling power was derived, and values for each model parameter were determined. A bicycle-mounted power measurement system was validated by comparison with a laboratory ergometer. Power was measured during road cycling, and the measured values were compared with the values predicted by the model. The measured values for power were highly correlated (R2 = .97) with, and were not different than, the modeled values. The standard error between the modeled and measured power (2.7 W) was very small. The model was also used to estimate the effects of changes in several model parameters on cycling velocity. Over the range of parameter values evaluated, velocity varied linearly (R2 > .99). The results demonstrated that cycling power can be accurately predicted by a mathematical model.
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A friction loaded cycle ergometer was instrumented with a strain gauge and an incremental encoder to obtain accurate measurement of human mechanical work output during the acceleration phase of a cycling sprint. This device was used to characterise muscle function in a group of 15 well-trained male subjects, asked to perform six short maximal sprints on the cycle against a constant friction load. Friction loads were successively set at 0.25, 0.35, 0.45, 0.55, 0.65 and 0.75 Nkg–1 body mass. Since the sprints were performed from a standing start, and since the acceleration was not restricted, the greatest attention was paid to the measurement of the acceleration balancing load due to flywheel inertia. Instantaneous pedalling velocity (v) and power output (P) were calculated each 5 ms and then averaged over each downstroke period so that each pedal downstroke provided a combination of v, force and P. Since an 8-s acceleration phase was composed of about 21 to 34 pedal downstrokes, this many v-P combinations were obtained amounting to 137–180 v-P combinations for all six friction loads in one individual, over the widest functional range of pedalling velocities (17–214 rpm). Thus, the individual's muscle function was characterised by the v-P relationships obtained during the six acceleration phases of the six sprints. An important finding of the present study was a strong linear relationship between individual optimal velocity (v opt) and individual maximal power output (P max) (n = 15, r = 0.95, P < 0.001) which has never been observed before. Since v opt has been demonstrated to be related to human fibre type composition both v opt, P max and their inter-relationship could represent a major feature in characterising muscle function in maximal unrestricted exercise. It is suggested that the present method is well suited to such analyses.
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The effect of fatigue as a result of a standard submaximal dynamic exercise on maximal short-term power output generated at different contraction velocities was studied in humans. Six subjects performed 25-s maximal efforts on an isokinetic cycle ergometer at five different pedaling rates (60, 75, 90, 105, and 120 rpm). Measurements of maximal power output were made under control conditions [after 6 min of cycling at 30% maximal O2 uptake (VO2max)] and after fatiguing exercise that consisted of 6 min of cycling at 90% VO2max with a pedaling rate of 90 rpm. Compared with control values, maximal peak power measured after fatiguing exercise was significantly reduced by 23 +/- 19, 28 +/- 11, and 25 +/- 11% at pedaling rates of 90, 105, and 120 rpm, respectively. Reductions in maximum peak power of 11 +/- 8 and 14 +/- 8% at 60 and 75 rpm, respectively, were not significant. The rate of decline in peak power during the 25-s control measurement was least at 60 rpm (5.1 +/- 2.3 W/s) and greatest at 120 rpm (26.3 +/- 13.9 W/s). After fatiguing exercise, the rate of decline in peak power at pedaling rates of 105 and 120 rpm decreased significantly from 21.5 +/- 9.0 and 26.3 +/- 13.9 W/s to 10.0 +/- 7.3 and 13.3 +/- 6.9 W/s, respectively. These experiments indicate that fatigue induced by submaximal dynamic exercise results in a velocity-dependent effect on muscle power. It is suggested that the reduced maximal power at the higher velocities was due to a selective effect of fatigue on the faster fatigue-sensitive fibers of the active muscle mass.
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Another way of improving time trial performance is by reducing the power demand of riding at a certain velocity. Riding with hands on the brake hoods would improve aerodynamics and increase performance time by ≈5 to 7 minutes and riding with hands on the handlebar drops would increase performance time by 2 to 3 minutes compared with a baseline position (elbows on time trail handle bars). Conversely, riding with a carefully optimised position could decrease performance time by 2 to 2.5 minutes. An aerodynamic frame saved the modelled riders 1:17 to 1:44 min:sec. Furthermore, compared with a conventional wheel set, an aerodynamic wheel set may improve time trial performance time by 60 to 82 seconds. From the analysis in this article it becomes clear that novice cyclists can benefit more from the suggested alterations in position, equipment, nutrition and training compared with elite cyclists. Training seems to be the most important factor, but sometimes large improvements can be made by relatively small changes in body position. More expensive options of performance improvement include altitude training and modifications of equipment (light and aerodynamic bicycle and wheels). Depending on the availability of time and financial resources cyclists have to make decisions about how to achieve their performance improvements. The data presented here may provide a guideline to help make such decisions.
Article
Purpose – The purpose of the present study was to examine the relationships between mechanical values (maximal velocity, force and power) generated on a cycle ergometer and sprint performance during the acceleration phase of a sprint start, using starting-blocks in trained male athletes.Methods – 7 male athletes volunteered to perform in a randomised order three 6 s sprints on a cycle ergometer against 0.4, 0.6 and 0.8 N.kg–1 resistive loads and three 30 m sprint starts. Maximal values of force, velocity and power generated on cycle ergometer and 5, 10 and 30 m times were recorded.Results – Average running speeds between 5 and 10 m and at 10 m were significantly related to maximal power per body mass (r = 0.931; p < 0.01 and r = 0.886; p < 0.01, respectively).Conclusion – Maximal power of the lower limbs related to body mass (measured during sprints on a cycle ergometer) seems to be a determinant variable for the very beginning of the initial acceleration phase (between 5 and 10 m) in sprint running, in this athletes group.
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Tractional resistance (RT, N) was determined by towing two cyclists on a racing bike in "fully dropped" posture in calm air on a flat track at constant speed (5--16.5 m/s). RT increased with the air velocity (v, m/s): RT = 3.2 + 0.19 V2. The constant 3.2 N is interpreted as the rolling resistance and the term increasing with v2 as the air resistance. For a given posture this is a function of the body surface (SA, m2), the air temperature (T, degree K), and barometric pressure (PB, Torr). The mechanical power output (W, W) can then be described as a function of the air (v) and ground (s) speed: W = 4.5.10(-2) Ps + 4.1.10(-2) SA (PB/T)v2 s, where P is the overall weight in kg. With a mechanical efficiency of 0.25, the energy expenditure rate (VO2, ml/s) is given by: VO2 = 8.6.10(-3) Ps + 7.8.10(-3) SA (PB/T)v2 s (1 ml O2 = 20.9 J). As the decrease of VO2max with altitude is known from the literature, this last equation allows the calculation of the optimal altitude for top aerobic performance. The prediction derived from this equation is consistent with the present 1-h world record.