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Eur J Appl Physiol (2001) 85: 191±194
DOI 10.1007/s004210100415

O R I GI N A L A R T IC L E

K. Chamari á S. Ahmaidi á J. Y. Blum á O. Hue
A. Temfemo á C. Hertogh á B. Mercier
C. PreÂfaut á J. Mercier

Venous blood lactate increase after vertical jumping
in volleyball athletes
Accepted: 3 February 2001 / Published online: 5 May 2001
Ó Springer-Verlag 2001

Abstract The aim of this study was to test the hypothesis that venous blood lactate concentrations ([La±])
would vary from the beginning of brief exercise. Maximal vertical jumping was used as a model of brief intense
exercise. Eleven healthy male volleyball players, aged
[mean (SE)] 18.5 (0.7) years, performed three exercise
tests with di€erent protocols, each separated by quiet
seated recovery periods of 45 min. After the ®rst test,
consisting of a single maximal jump [lasting @0.6 s for
the pushing phase, and in which the subjects jumped 64
(2.2) cm], forearm venous [La±] increased signi®cantly
with respect to rest at 1 min (t1), 3 min (t3), and 5 min
(t5) of recovery. The second test, comprising six maximal
jumps, each separated by 20-s recovery periods, resulted
in an unchanged [La±] with respect to the baseline value.
After the third test [i.e., six consecutive maximal jumps
that lasted a total of 7.36 (0.33) s], [La±] increased signi®cantly at t3 and t5 with respect to the pre-test value
(F=10.3, P<0.001). We conclude that a signi®cant venous [La±] increase occurs after vertical jumping. This
result may be explained by the activation of lactic anaerobic metabolism at the very onset of exercise, which
participates in energy production and/or in the resyn-

K. Chamari á S. Ahmaidi (&) á A. Temfemo
Laboratoire de Recherche ``APS et Conduites Motrices:
Adaptations-ReÂadaptations'', Faculte des Sciences du Sport,
AlleÂe P. Grousset, 80025 Amiens Cedex, France
E-mail: said.ahmaidi@ca.u-picardie.fr
Tel.: +33-3-22827903
Fax: +33-3-22827844
J.Y. Blum á B. Mercier á C. PreÂfaut á J. Mercier
Laboratoire de Physiologie des Interactions,
HoÃpital Arnaud de Villeneuve,
34295 Montpellier Cedex 05, France
K. Chamari
Centre National de la MeÂdecine du Sport,
1003, Tunis, Tunisia
O. Hue á C. Hertogh
Laboratoire ACTE, UFR-STAPS Antilles-Guyane,
Campus de Fouillole, 97159 Pointe aÁ Pitre Cedex, France

thesis of the phosphocreatine that was used during such
brief exercise.
Keywords Brief exercise á Glycolysis á Lactate á
Volleyball athletes

Introduction
During muscular exercise, energy production depends
upon both anaerobic and aerobic metabolism. Margaria
et al. (1964) have suggested that lactic anaerobic metabolism contributes to energy production after 20 s of
exercise. More recently, however, our group (Mercier
et al. 1991) showed that venous blood lactate concentration ([La±]) increased signi®cantly after 6 s of intense
exercise, and it was concluded that lactic anaerobic metabolism probably contributes signi®cantly to energy
production during such short-duration, intense exercise.
In the same way, Gaitanos et al. (1993) showed that 50%
of the working energy in a 6-s intense sprint was provided by alactic anaerobic metabolism and 50% by the
glycolytic pathways. Finally, Balsom et al. (1992) hypothesized that lactic anaerobic metabolism would contribute to energy production even from the very ®rst
second of exercise. This hypothesis is supported by the
fact that glycolysis and glycogenolysis are immediately
activated by the Ca2+ that is released by muscular contraction (Chasiotis et al. 1982). Study of the possible
activation of the glycolysis pathways at the beginning of
exercise would be of interest for sports that include extremely brief e€orts. Volleyball, for example, requires a
short, but intense e€ort (i.e., maximal vertical jumping
that is performed repetitively during both training and
competition). Maximal vertical jumping seems an appropriate model for intense and extremely brief exercise
because this task lasts for about 0.5 s (Hertogh et al.
1992). In order to test the hypothesis that lactic anaerobic pathways are already activated from the very ®rst
seconds of exercise, venous blood [La±] was measured in
healthy male volleyball players after vertical jumping. In

192

addition, because Paiment (1992) reported that vertical
jumping performance does not decrease over the course
of a volleyball match, the e€ects of the repetition of
vertical jumping on venous blood [La±] were also studied.

arm movement, (2) six arm movements each separated by 20 s of
recovery, and (3) six consecutive arm movements without any
recovery between movements.

Methods

Values are expressed as mean (SEM). In order to investigate the
time course of changes in [La±] during each protocol, a one-way
(recovery time) analysis of variance (ANOVA) was performed.
When the ANOVA-F ratio was signi®cant, a contrast test was then
performed. The level of statistical signi®cance for the entire study
was set at P<0.05.

Subjects
Eleven healthy male volleyball players [mean (SEM) age 18.5
(0.7) years, height 1.87 (0.04) m, body mass 85.2 (4) kg] volunteered and gave their written informed consent to participate in
this study. All trained three times a week (3´1.5 h) and regularly
competed at the regional level.
Experimental procedures
Vertical jump test
Exercise consisted of jumping from the standing position (i.e., rapid
¯exion/extension of the lower limbs). The arms were ¯exed before
the jump, with the hands at the level of the chest, then during the
jump the arms were rapidly extended straight up as in the defense
gesture in a volleyball match. The height of the jump (Hj) was
measured with the aid of a video camera that was equipped with a
replay system. The camera was positioned at the level of the predetermined mean maximum jump height (Hjmax) of the subjects. In
order to measure the actual height jumped (Hj; equal to the height
of the subject's head at the top of the jump minus the height of the
subject) the subjects jumped between the camera and a graded
ruler. The replay system allowed Hj determination with an error of
‹2.5 cm.

Statistical analysis

Results
The mean Hjmax performed by the subjects was 64
(2.2) cm. After SgJ, [La±] increased signi®cantly at t1, t3,
and t5 compared to the baseline (resting) value (F=10.3,
P<0.001; Fig. 1). After the 6SpJ protocol, [La±] did not
di€er signi®cantly from the pre-test value (Fig. 2). After
the 6CsJ protocol [performed in 7.36 (0.33) s], [La±] was
signi®cantly greater than pre-exercise value at t3, and t5
(F=10.3, P<0.001; Fig. 3). Moreover, when the vertical
jump was replaced by only the movement of the arms,
[La±] was unchanged in the three exercise protocols. For
the ®rst protocol, the [La±] values varied between
1.29 mmolál±1 at rest to 1.28 mmolál±1 for the highest
value observed throughout recovery. For the second and
third protocols, [La±] varied from 1.38 mmolál±1 to
1.41 mmolál±1 and from 1.43 mmolál±1 to 1.44 mmolál±1,
respectively.

Protocol
Subjects familiarized themselves with the testing procedure during
the three last volleyball training sessions, and at that time maximal
performance was measured. The mean value of the three best
performances was considered as Hjmax. The experimental procedure was carried out at the laboratory in the morning, 3 h after
they had consumed a standardized breakfast. A medical examination was performed. Then the anthropometric values were recorded. Finally, a catheter was placed in the antecubital vein
30 min before exercise testing.
Personal observations on 17 volleyball matches showed that
during a match, each time a player passed from one of the three
forward positions, he jumped about six times, with a mean recovery
of @20 s between jumps. Based on these observations, the experimental procedure consisted of a stretching warm-up period of
5 min followed in a random order by three exercise protocols
separated by 45 min of quiet seated rest. Exercise protocols were as
follows: (1) a single maximal jump (SgJ), (2) six maximal jumps
separated by 20 s of recovery (6SpJ), and (3) six consecutive jumps
without any recovery between jumps (6CsJ).
During each vertical jump, the subjects had to perform
Hjmax‹2.5 cm. Two venous blood samples were drawn in pre-test
conditions (i.e., just before each exercise protocol), and the baseline
[La±] value was calculated as the mean of these two measurements.
Blood samples were then drawn immediately after jumping (t0) and
at 1 min (t1), 3 min (t3), and 5 min (t5) of recovery. [La±] analysis
was carried out using a method described in an earlier study
(Mercier et al. 1991).
In order to determine the role of the upper limbs in the [La±]
increase, three of the subjects came to the laboratory on a separate
day. They performed the same protocol with only the movement of
the arms during vertical jump (i.e., a rapid extension/¯exion,
without jumping). Exercise protocols were as follows: (1) a single

Discussion
The results of this study showed that venous blood [La±]
increased signi®cantly after a maximal vertical jump
(SgJ) and six consecutive jumps (6CsJ). After six jumps,
each separated by 20-s recovery periods (6SpJ), [La±] did
not increase signi®cantly.
In this study, the vertical jump was performed from
the standing position and was measured with a video
camera. In the study of Grassi et al. (1991), the subjects
jumped from a standard squat position (knee angle of
@90°) keeping their hands on their hips. This testing
procedure, which resulted in a lower jumping performance than ours, was adopted to avoid any interference
during the push phase in order to obtain as precise a
peak power as possible on a force platform. In another
study (Vandewalle and Friemel 1989), the jumping performance was measured by using a horizontal wooden
slat that had to be touched by the subject's head. In the
present study, the aim of the exercise was to obtain
maximal jumping and then to measure the subsequent
[La±]; thus, the testing protocol was designed to match as
closely as possible the spontaneous jumping movement
performed during volleyball matches. The measurement
technique was also modi®ed to avoid disturbing the
subjects and to ensure maximal performance.

193

Fig. 1 Venous blood lactate concentration ([La±]) after a single
maximal vertical jump. Measurements were made in resting
conditions (Pre-ex), at immediate post-jumping (t0), and at 1 min
(t1), 3 min (t3), and at 5 min (t5) of recovery. Comparisons are made
with respect to the pre-exercise (resting) condition. ***P<0.001

Fig. 2 Venous blood [La±] after six maximal vertical jumps, each
separated by a 20-s recovery period. Measurements were made in
resting conditions (Pre-ex), at immediate post-jumping (t0), and at
1 min (t1), 3 min (t3), and at 5 min (t5) of recovery. Comparisons
are made with respect to the pre-exercise (resting) condition

The [La±] increase observed after the SgJ may be
explained by the recruitment of lactic anaerobic metabolism. Indeed, it is well known that the breakdown of
glycogen is dependent upon the phosphorylase enzyme,
which is controlled by two mechanisms. One system is
hormonally mediated and depends upon the extracellular actions of epinephrine and the intracellular action of
cyclic AMP (cAMP). This mechanism is too slow to
explain the rapid glycolysis that occurs during the onset
of heavy exercise. Therefore, a mechanism mediated by
Ca2+, which is released from the sarcoplasmic reticu-

Fig. 3 Venous blood [La±] after six consecutive vertical jumps.
Measurements were made in resting conditions (Pre-ex), at
immediate post-jumping (t0), and at 1 min (t1), 3 min (t3), and at
5 min (t5) of recovery. Comparisons are made with respect to the
pre-exercise (resting) condition. ***P<0.001

lum, constitutes a parallel control mechanism. Of the
two mechanisms controlling glycogen metabolism in
muscle, the local Ca2+-mediated mechanism is probably
the more important. Since the exercise performed here
was extremely brief (i.e., @0.6 s for the pushing phase;
Hertogh et al. 1992), this observation con®rms the hypothesis of Balsom et al. (1992), who suggested that
glycolytic pathways may be activated at the very beginning of exercise. This observation is logical from a
biochemical point of view, as glycolysis and glycogenolysis are immediately activated by the Ca2+ liberated
by muscular contraction (Chasiotis et al. 1982). Indeed,
it is assumed that anaerobic glycolysis is activated immediately from the beginning of the exercise in order to
recruit the energy for muscular contraction. As a matter
of fact, the activation of phosphorylase occurs immediately after the start of exercise, since it is activated by the
increase in intracytoplasmic Ca2+ caused by the in¯ux
of nerve activity (Stainsby 1986). Furthermore, the cascade of enzymatic reactions that permits the transformation of glucose into pyruvate is activated once
inorganic phosphate is liberated following the hydrolysis
of ATP as a result of muscular contraction. A part of the
[La±] increase observed could also be responsible for the
resynthesis of the phosphocreatine that was hydrolyzed
during exercise (Di Prampero et al. 1973).
The [La±] increase observed here (i.e., 0.75 mmolál±1)
was small, but not negligible with respect to exercise
duration. Indeed, it has been shown that 5 min after an
intense 6-s cycle ergometer sprint, a slightly higher
magnitude of [La±] increase may be observed (Mercier
et al. 1991). Moreover, Gaitanos et al. (1993) quanti®ed
the participation of lactic anaerobic metabolism in an
intense 6-s exercise and found it to be of about 50%.
From the present protocol it was not possible to quan-

194

tify the participation of lactic anaerobic metabolism to
energy production, but from the [La±] increase observed
after such a brief exercise we can suggest that the participation is not negligible, although alactic anaerobic
metabolism probably predominates (Grassi et al. 1991).
From the [La±] increase observed it is possible to
draw an energy balance of the single jump as follows.
The average Hj was 0.64 m, thus the external work
(neglecting that for the moving upper limbs) was
9:81 0:64 ˆ 6:3 J kg 1 jump 1 . Since the energy
equivalent of lactate accumulation in blood is about
3 ml O2ákg±1 (63 Jákg±1) for an increase of 1 mM of
blood [La±1] (Di Prampero and Ferretti 1999) and since,
under the present conditions, the blood [La±1] increased
by 0.75 mM, then the amount of energy released from
lactate sources amounts to 0:75 63 ˆ 47 J kg 1 . Assuming that the energetic contribution from aerobic
sources was negligible because of the very short exercise
duration, then the overall eciency of the present single
jump can be calculated as 6:3=47 ˆ 0:135.
Other phenomena can not be ruled out to explain the
observed results. The [La±] increase may be the result of
activation of the glycolytic pathways by stress-induced
catecholamine release (Christensen et al. 1979), and/or a
reduction in [La±] oxidation, as the measured concentration is the result of [La±] production and clearance
(Brooks 1991). Nevertheless, the possible catecholamine
response could also have resulted in activation of the
glycolytic pathways. To verify that the increase venous
blood [La±] was not the result of arm movement, three
subjects performed the same testing procedure with only
the movements of the arms. [La±] did not increase,
suggesting no participation of the arms in the [La±] increase even their equilibrating role. Granier et al. (1996)
showed that after an intense 6-s cycle ergometer sprint,
the arterial-venous [La±] di€erence was positive at the
level of the forearms. In consequence, we can speculate
that in the present study [La±] might have been underestimated.
After the 6SpJ, [La±] was similar to the resting value.
A possible explanation may be that in such repeated
exercise, aerobic metabolism is already activated (Balsom et al. 1994) to allow ATP and creatine phosphate
resynthesis with a concomitant lactate removal during
the recovery periods separating the jumps (Brooks 1991;
Margaria et al. 1969). It is then not possible to draw an
energy balance for the repeated jumps experiment, as the
contribution of O2 consumption to the overall energy
requirement can not be neglected.
The [La±] increase after the 6CsJ was not higher than
that observed after the SgJ, despite the longer exercising
period. This result suggests that [La±] is not correlated
with a repetition of the same exercise. Moreover, the
magnitude of lactate increase, @0.5 mmolál±1 in this
protocol lasting @7 s, is lower than that induced by a 6-s
intense sprint (@3.9 mmolál±1; Mercier et al. 1991).
These results may explain the variation in jumps
during a volleyball match. The block jumps always
occur after a rest period. Indeed, the players have to

observe the opposing team before jumping to defend.
Conversely, a run-up usually precedes smash jumps. The
decrease in smash jumps is possibly the consequence of
lactate accumulation, because recently Hogan et al.
(1995) reported that an increased muscular [La±] reduced
muscular tension development independently of pH decreases. Our study showed a small e€ect of jump
movement in [La±] variations; we speculate that the runup may play an important role in [La±] increase.
It can be concluded that venous blood [La±] increases
signi®cantly after a very intense exercise lasting less than
1 s. This result may be explained by the activation
of lactic anaerobic metabolism, which participates in
energy production and/or to the resynthesis of the
phosphocreatine that was used in such brief exercise.

References
Balsom PD, Seger JY, SjoÈdin B, Ekblom B (1992) Physiological
responses to maximal intensity intermittent exercise. Eur J Appl
Physiol 65:144±149
Balsom PD, Gaitanos GC, Ekblom B, SjoÈdin B (1994) Reduced
oxygen availability during high intensity exercise impairs performance. Acta Physiol Scan 152:279±285
Brooks GA (1991) Current concepts in lactate exchanges. Med Sci
Sports Exerc 23:895±906
Chasiotis D, Sahlin K, Hultman E (1982) Regulation of glycogenolysis in human muscle at rest and during exercise. J Appl
Physiol 53:708±715
Christensen NJ, Galbo H, Hansen JF, Hesse B, Richter EA, TrapJensen J (1979) Catecholamines and exercise. Diabetes 28:58±62
Di Prampero PE, Ferretti G (1999) The energetics of anaerobic
muscle metabolism: a reappraisal of older and recent concepts.
Respir Physiol 118:103±115
Di Prampero PE, Peeters L, Margaria R (1973) Alactic O2 debt and
lactic acid production after exhausting exercise in man. J Appl
Physiol 34:628±632
Gaitanos GC, Williams C, Boobis H, Brooks S (1993) Human
muscle metabolism during intermittent maximal exercise. J Appl
Physiol 75:712±719
Granier P, Dubouchaud H, Mercier B, Mercier J, Ahmaidi S,
PreÂfaut C (1996) Lactate uptake by forearm skeletal muscles
during repeated bouts of short-term intensive leg exercise in
man. Eur J Appl Physiol 72:209±214
Grassi B, Cerretelli P, Narici MV, Marconi C (1991) Peak anaerobic power in master athletes. Eur J Appl Physiol 62:394±399
Hertogh C, Micalef JP, VaissieÁre F (1992) Test d'eÂvaluation de la
puissance maximale. Sci Sports 6:185±191
Hogan MC, Gladden LB, Kurdak SS, Poole DC (1995) Increase
[Lactate] in working dog muscle reduces tension development
independent of pH. Med Sci Sports Exerc 27:371±377
Margaria R, Cerretelli P, Mangile F (1964) Balance and kinetics of
anaerobic energy release during strenuous exercise in man.
J Appl Physiol 19:623±628
Margaria R, Oliva R D, Di Prampero PE, Cerretelli P (1969) Energy utilization in intermittent exercise of supramaximal intensity. J Appl Physiol 26:752±756
Mercier J, Mercier B, PreÂfaut C (1991) Blood lactate increase
during the force-velocity exercise test. Int J Sports Med s12:17±
20
Paiment M (1992) Volley-ball at the international level: Barcelona
Olympic Games men's category. Int Volley Tech 4:22±24
Stainsby WN (1986) Biochemical and physiological bases for lactate production. Med Sci Sports Exerc 18:341±343
Vandewalle H, Friemel F (1989) Tests d'eÂvaluation de la puissance
maximale des meÂtabolismes aeÂrobie et anaeÂrobies. Sci Sports
4:265±279


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