東京大学教養学部体育学紀要 (1993)27, 1〜 8

Brief review

Muscle characteristics of Japanesescooer players using NMR
Shin-ya Kuno

Dept. of Sports Sciences, College of Arts and Sciences,

The University of Tokyo21Kuno

Introduction

This is a brief review on the muscle
characteristic of elite soccer players in Japan.
The information about the muscle characteristicof elite soccer players seems abundant but is, asa nratter of fact, quite scare. This is because

thigh obtained from MRI. It covers the section
from the knee to the upper part of thigh. Themuscles, bones, and fats are clearly depicted.

muscles are concealed and, therefore, can hardly

be seen directly. The Freld of sports sciences
witnessed the initiation of muscle biopsy in1960's, enabling us to obtain the direct
information about the muscle cell. The muscle
biopsy is, however, not a practice athletes like toundergo as it is accompanied by an incision. It
may be further difficult to inspect in-seasonchanges of a muscle. These are the reasons forsource data on elite athletes, and it has remained
unknown within a black box how the muscles of{such athletes are characterized and what changes
take place due to training.

tr'igure 2 Axial image of thish obtained froml,lRI.

2 NMR
We have studied the muscle characteristic ofJapanese top ranked soccer players using the MR
equipment (Fig.1). This equipment enabled us toobtain the information about elite athletes as itallows morphological and biochemical information

It covers the section from kneeide (top) to upper thish (bottom).

sFigure 3 shows a picture taken by a method
called MRS to obtain muscle energy metabolic

first, it is discussed that NMR data on a topic ofinformation. From left to right, inorganicand ATP are shown.
And, in this spectrum, the state at rest is
shown up to the 4th streak from the bottom,

the morphological characteristic of Japanese topranking soccer players' muscles as well as of thethat during exercise by the next 6, and the otherof the streaks are recovery. When exercise isabout muscles to be obtained in uivo through theirradiation of a living body with magnetism. At

phosphate, phosphocreatine,relationship between in-season training and muscle

started, inorganic phosphate increases in its peakcharacteristic. Figure 2 shows an axial image ofwhile phosphocreatine decreases. The use of 3lP
MRS also permits us to determine an
intracellular pH.

Moreover, since the reductionin the intracellular pH has been foundproportional to the amount of lactic acidaccumulated within a muscle cell, ti

can beinferred whether or not a glycolytic system has
been mobilized if the value of intracellular pH is) Such information has so far been
unable to be obtatined unless subjected to muscle
kno*n.

Figure I}trR equipment.

biopsy.

tMuscle Characteristics of Japanese Soccer Players Using NMR

for volleyball players who repeat such a motion
during a game. Figure 4-D shoun an example ofthose players observed to have the highest
developed muscles with very little subcutaneous
fat among the elite athetes contained. He wasan athletic pole jumper and had held a Japanesel00-10 PPM

Figure 3 A series of 3lP URS spectra invivo at rest ( lotver 4 traces),
during exercise (middle 6 ) andrecovery (upper 4 ).t'Pi, inorganic phosphate ; PCr,
phosphocreat ine I o, i, !, threephosphate groups of adenosine
triphosphate (ATP)record until recently. Figure 4-E shoun an
untrained male's axial image. This subject, unlike
an athlete, has characteristically less developed
muscles and abundant subcutaneous fat. Figure
5 shoun cross-sectional areas of variors mtrscle
groups calculated from each image of thethighsobtained by Ivm,I.{' Th" topide of a picture
corresponds with the upper part of thigh and lheloruer part covers the section around upper partof the knee. From left to right, each column
glves the area of hamstring, M. vastus medialis
and M. rrastus intermedius combined, M. vastus
lateralis, and M rectus femoris, respectively.

This figure DBy, therefore, be considered as amorphological aspect of thigh muscles. They are,3 Cmparisn between lxrcoer pla5rers of mudeManea andother qut's €rents
Figure 4-A is an a:rial image of the thighdepicted by MRI for a national soccer player asa member of the japanese delegation. Themuscle quadriceps femoris and hamstring areamong those well trained. Subcutaneous fat is
also characteristically scarce. Figure 4-B shmrs
that an MR imaging of a judo player who has
won a world championship trvice. It isparticularly notable that the area of hamstring islarger than the soc@r player's large one. That
subject, though weighing 90 kg, has scaroe
subcutaneous fat, indicating a large compsition
ratio of muscles. Figure 4-C shoun that the MR
imaging of a male volleyball player of the Japannational team.
This player has mostcharacteristically, highly developed IvL rectus
femoris. It is generally well that M. rectus
femoris plays an important role in jumping
motion. This picture indicates that thedevelopment of this muscle is still ever importantfrom left to right, the muscles of a track andfield athlete, judoist, speed skater, soccer player,
vollyball player and the untrained. A group ofathletes used consisted of those who, represented
each of all-Japan teams and who were ranked
l0th or higher in each event in Japan. The
abore comparison clarifies different characteristics
in the morphological aspect of thigh mtrscles fordifferent sport events.

Figure 6 shona a comparison betrreen a socoer
player and sprinter. Quite characteristically, there

is no significant difference observed in the crosssectional area of upper-thigh, but in the lower

part of thigh, the soc@r player definitely extribitsa larger crms-sectional area of muscle. It isconsidered that this might be partly due to thefact that a coccer player not simply runs in astraight direction but also repeats the mostimportant mode of kicking motion in hisperforman@. At present, horuever, this cannot
be explained to a full extent but is considered as

an interesting fact. It also indicates the necessity

Kuno

博・Ｄ⁚
︲︲︱
■●．︐︲︐︲⁚︲Ｌ髯鵞鶉Ｌ['igure 4 An el ite athlete' s image of thishby MRI.o) A, soccer ; B, judo;C,volleyball ; D, pole jumper E,
unt ra ined

to €rry out such a training as applies load ro all
over the thigh when a soccer player executes
strength training.

Figure 7 shona the area of muscle quadriceps
femoris in its upper ( 70 %) and middte ( 50 %)and lower ( 30 %) parts of players in all Japan,
Olympic team the lst division of Japan Soccer

L,eague, respectively. 2 ) The All Japan extribits aMuscle Characteristics of Japanese Soccer Players Using NMR(cm2)
ぶ ＬＨＯ300■ Ｎロ1a;■∞凸0(b) 300

CSAコ MA MQF HM

RF VM

VL rat+VII I200２Ｏ ｍCSA凸MQF HM＊口凸■00VMVL◆V=:L
Figure 5 Cross-sect iona I areas 0f var iousmuscle group calculated from eachol
ima ge o f th igh ob ta ined f rom UR I
n:6
* IOt

rr#t mllll fotg6n) tnrl Ellll +I+r!t

rkt''l凛ｍ

剛趙

I l.Rectus Fcmoris
W l.Vrslus taleolis
E I.Yaslus lnlermediusrl.Vaslus ledialis
Figure 6 Comparison with soccer players andsprinters i n cross-seetional areas
ll.0uadriceps Femotis\/LfetFigure 7 Huscle cr0ss-sectional area ofthish in All Japan (JPN), 0lympicand Youth (0L) and Japan soccerSprinl n:7Soccer

cSA TMA rll(lF IIltil RF t$,,league (JSL) players. 2)(a), upper thigh ; (b), middle
thigh ; (c), lower thish CSA,
cross-sectional area; TUA, total
muscle area ; llQF, quadriceps
femoris ; Hll , hamstring ; RF,
rectus femoris ; V[{, vastusmediaris ; VI, vostus intermedius; VL, vEstus lateralis}l.Hamslringsof various musc 1e group'lsignificantly higher value at every location and inboth muscle goups than that of player from theJapan I-eague players. This tendency is also
observed in isokinetic strength, (Fig.8 ) andanaerobic power ( Fig.g).

In consequence, asa pmsible cause for the higher values in muscle
strength and anaerobic power exhibited by an all
Japan group, the greater of muscle mass may becited. It is, therefore, be important to maintaina certain amount of muscles or more of it whenKuno

a soccer player is to be trained. Strength
training among others is assumed to be the mosteffective method to increase the amount ofα m)■ JPN400300□ JSL200

ホロN OLmuscles.

41000r'30 rE0450 30 1804s0 30 1E0450 30 1E0450 (deg/sec)

L rrn, --Lrcrt I L risht -l nn
I Extension llFlexion

the elimination for the ltalian World Cupt' TheIIFigure 8 Leg extens ion and flexion torquein All Japan (JPN), 0lYmPic andYouth (01) and JaPan soccer league(JSL) P IaYe rs".

鰐 )1200bトMuscle metabolism during mmpetition peridw MRs
Figure 10 shows in muscular pH observed by
MRS from an all Japan players before and after800●餞400

0subjects were kinetically loaded within the MR
equipment and the muscle energy metabolism atthat time was measured. The work rate of
kinetic loading applied was not different beween
before and after the elimination. As seen fromthis frgure, the pH was scarcely reduced evenduring exercise before the elimination. In viewof an ATP supply system, the energy for such
exercise can be deemed to have completely been
almost covered by the aerobic system.
Nevertheless, despite the same exercise taken
after the elimination, the pH dropped
considerably. This means that a glycolytic system
was also mobilized to cover the enerry suppliedin deficienct by the aerobic system flor theexercise. For this reason, the muscles are(b)(Wrkg)
五￨.0０

一 ∞ち卜■ｏ卜ｏ餞

20JPN

OL0。

00。

4JSL

E Maximal anaerobic power
tr 40 second power
Figure I }{axima I anae robi c p0rrre r and 40

reSt1 0Xerclso oxo劇 so l「0∞ VOⅣ

123'45612315
Tfru (rnh)second porver by bicyc 1e exerci seFigure 10 Changes in muscular pH observedin All JaPan (JPN), 0lYmPic andYouth (01) and Japan soccer league

f ro*3lP l,{RS in a Japan soccer(JSL) p lave rs2).

seasontl

leasue(JSL) player during aMuscle Characteristics of Japanese Soccer Players Using NMR

supposed to be in quite a fatigued state ar thetiure of measurement after the elimination. This
trend held true of muscle strength, exemplified bya case of reduction by as much as 30 o/o .')Figure t I shows the state of changes in themuscular pH of a certain professional player
when undergoing tha same test intermittently
during a season.e ) The lowest value is shown by
an off-season measurement and it seems
understand able that the muscular condition
depends largely up)n the extenr to which themuscles were trained. In the case exemplified

C-ondusircn

Figure LZ shows a certain player currently as amember of the Olympic team. The amount ofmuscles is smaller with considerable amount offat. In fact, however, this is not a special casebut rather observed in a large number of players
in Japan. Most of them are the players
belonging to the current J League. Therefore,
this makes us feel that no\il is the time to fullyreconsider the way of strength training and highpo\iler training for Japanese soccer players.

previously, no strength or high-power training wasgiven for about one-month period of the World-Cup elimination. What was responsible for themuscle fatigue after the competition may be due
not only to the fatigue during the period ofcompetition but also the absence of a@ompanying

training. Because it has so far been found thatthe absence of such training for amonth

deteriorates the muscle capability considerably. Itis, therefore, recommended that the strength
training and high-power training showed be added

to the phpical training during middle or longterm competition seasons.
L

7.10

Figure 12 Axial imate ofthish in elitesoccer p laye rszl
︒ ﹄聖7。

00

This pryrwits presented at sprts medicine■ ｏ ﹄ 口Ｈ

seminar in 10th Asian Cup frnal chanpionshiplW at Hiruhima.

6.90

6。

Rererenc鶴80

1reStFigure ll

Ex l

Ex 2Reco。 lReco。 2(0〜 1分 )(3〜 4分 )(0〜 1分 )(4〜 5分 )勝田

cup6と(.:pre,▲ :post)

茂(1990)シ ーズ ン を通 しての ハ イパ ワーお よびの よ うな影 響 を及 ぼすか 一 NMRに よる非侵襲 的 検 討 一、

fOrm 31P MRS in an all Japanelimination for the ltalian World広、久野譜 也、 西嶋 尚彦 、 山中邦 夫、松 本光弘 、筋カ トレーニン グが大学 サ ッカー選手の 筋機 能 に対 して どChanges in muscular pH observedsoccer playerbefore and after the秋間

トレーニン グ科学、2, 78‑83.

2

秋間

広、久 野譜 也、西嶋 尚彦 、 丸山剛 生、松 本光弘、

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4

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5

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