matsuba and shimamura s report on the exercise physiology and performance testing of racehorses ( fig . 1fig .
this report was a large book of 294 pages ( b5 size ) consisting of 2 parts ; the 
 first part was entitled  exercise physiology of the racehorse  , and the second part was entitled  performance testing of the racehorse  . ) was a large book of 294 pages ( b5 size ) consisting of 2 parts ; the first part was entitled 
exercise physiology of the racehorse  , and the second part was 
 entitled  performance testing of the racehorse  .
research results obtained from a large - scale project during the period of 1928 to 1932 , which was conducted at 
 the shimofusa imperial farm and the koiwai farm , the two greatest farms for racehorses at that time , and included a total of 92 thoroughbred racehorses , were 
 reported in this book .
matsuba and shimamura of the university of tokyo played major roles in this study , and were assisted by 25 students .
this project was 
 performed as a commissioned research project from the teikoku keiba kyokai ( the imperial racing association ) . because this report was written using an archaic 
 form of japanese language characters
nevertheless , it was a valuable contribution because the raw numbers for 
 every variable measured were cited and it contained a large number of data tables ( table 1table 1.raw numbers and percentages for pulse rate obtained at the koiwai farm during the period of july 29th to august 7th , 1931horse nameraw numberpercentageprepost1 hr2 hr3 hrprepost1 hr2 hr3 hrdai 4 rachidia34106403434100.0310.3117.7100.0100.0shining star3398413536100.0297.0123.4106.1109.1dai 6 shian mor34112393637100.0329.4109.5105.9108.8dai 4 shian mor36116423836100.0322.2113.8105.5100.0dai 2 shian mor3494403937100.0276.4117.7114.7108.8dai 3 shian mor30102373434100.0340.0123.3113.3113.3dai 5 shian mor34104443634100.0305.8129.4105.9100.0dai 7 shian mor3698363232100.0272.2100.088.188.1dai 19 koiwai3094373330100.0313.3123.2110.0100.0average33.4102.739.635.234.4100.0307.5118.6105.4103.0trot 800 m , canter 1,600 m , gallop 800 m. the person in charge of experiment : shigeo matsuba .
this report was a large book of 294 pages ( b5 size ) consisting of 2 parts ; the 
 first part was entitled  exercise physiology of the racehorse  , and the second part was entitled  performance testing of the racehorse  .
trot 800 m , canter 1,600 m , gallop 800 m. the person in charge of experiment : shigeo matsuba .
cited from a report by matsuba and shimamura . the first chapter of the first portion of the book began with a sentence regarding the factors necessary for exercise including healthy internal organs and tough 
 skeletal muscles , especially for racehorses for which high speeds must be attained within a short time . matsuba and
shimamura stated that the reason why this 
 project was performed was that while there were many papers on the exercise physiology of the warhorse at that time , there were few reports on the exercise 
 physiology of the racehorse .
as an overall research plan , the first and second years were considered to be preparatory periods for conducting research on the 
 exercise physiology of the racehorse , and the third to fifth years were to be intensive periods for research on exercise physiology and for evaluating performance 
 testing of racehorses .
they stated that they decided to measure many variables because most previous studies on the exercise physiology of racehorses had measured only a couple of 
 variables .
the first seven variables studied were defined as being clinical variables , and the eighth to 
 twentieth variables were defined as blood variables as follows : 1 ) body temperature , 2 ) respiratory frequency , 3 ) pulse rate , 4 ) blood pressure , 5 ) cardiac 
 function ( auscultation of cardiac sound ) , 6 ) state of conjunctiva , 7 ) state of perspiration , 8) specific gravity of blood , 9 ) erythrocyte count , 10 ) leukocyte 
 count , 11 ) hemoglobin concentration , 12 ) packed cell volume ( pcv ) , 13 ) viscosity of blood , 14 ) blood glucose concentration , 15 ) plasma co2 
 concentration , 16 ) plasma ph , 17 ) serum freezing point depression , 18 ) serum refractive index , 19 ) erythrocyte fragility , and 20 ) serum spectrogram .
fourteen of 
 these variables were measured during the first year , and all 20 variables were measured in the fourth year , while 10 variables were measured in the fifth year . 

measurements were made before exercise ( pre ) , just after exercise ( post ) , 1 hr after exercise ( 1 hr ) , 2 hr after exercise ( 2 hr ) , and 3 hr after exercise ( 3 
 hr ) .
a summary of surveys and actual performance protocols is provided in table 2table 2.summary of surveysnumberdateplacehorseexercise protocol1st1928 ( aug .
14th21st)shimofusa farm 6 ( 6 four - yo : 6 colts)c ( 11,200 m)2nd1928 ( nov .
12th20th)shimofusa farm 7 ( 3 two - yo & 4 four - yo : 4 colts & 3 fillies)c ( 6,400 m)3rd1929 ( jul .
16th26th)shimofusa farm10 ( 7 two - yo & 3 three - yo : 3 colts , 2 fillies & 5 geldings)c ( 5,000 m ) , w ( 200 m ) , or t ( 200 m)4th1929 ( jul .
16th24th)shimofusa farm10 ( 2 two - yo , 6 three - yo & 2 four - yo ; 10 geldings)c ( 5,000 m ) , w ( 200 m ) , or t ( 200 m)5th1930 ( mar .
22nd31st)shimofusa farm 9 ( 9 two - yo : 9 colts)t ( 800 m ) + c ( 1,600 m ) + g ( 800 m)6th1931 ( mar .
16th31st)shimofusa farm15 ( 15 two - yo : 7 colts & 8 fillies)t ( 800 m ) + c ( 1,600 m ) + g ( 800 m)7th1931 ( jul .
7th)koiwai farm 9 ( 9 two - yo : 9 colts)t ( 800 m ) + c ( 1,600 m ) + g ( 800 m)8th1932 ( jun .
18th24th)shimofusa farm16 ( 16 two - yo : 8 colts & 8 fillies)t ( 800 m ) + c ( 1,600 m ) + g ( 800 m)9th1932 ( aug .
3rd6th)koiwai farm10 ( 10 two - yo : 3 colts & 7 fillies)t ( 800 m ) + c ( 1,600 m ) + g ( 800 m)although various exercise protocols were used in the 1st and 2nd years ( 1st to 4th surveys ) , the same exercise protocol was used from the 3rd to 5th years 
 ( 5th to 9th surveys ) .
w , walk ; t , trot ; c , canter ; and g , gallop .
two - yo , 2-year - old - horse ; three - yo , 3-year - old - horse ; and four - yo , 4-year - old - horse .
cited 
 from a report by matsuba and shimamura .. the total number of thoroughbred racehorses used in this study was 92 ( 71 two - year - old , 9 three - year - old , and 12 four - year - old ; 49 colts , 28 
 fillies , and 15 geldings ) , and all were raised at either the shimofusa imperial farm or the koiwai farm .
the total duration of each survey was long , and a total of 61 days were used for the surveys .
although a variety of exercise protocols were used during 
 the first and second years ( the first to fourth surveys ) , the same exercise protocol ( trot , 800 m , canter , 1,600 m , gallop , 800 m ) was used from the third to 
 fifth years ( the fifth to ninth surveys ) . in this article ,
the authors showed changes in selected variables . although data were plotted individually in the 
 original report ( fig .
. 2.pulse rate measured at the koiwai farm in 1931 ( july 29th  august 7th ) .
data obtained from each horse were plotted individually . cited from a report by 
 matsuba and shimamura . )
, the authors generated graphs ( mean  sd ) using data from tables obtained during the seventh survey on july 29 , 1931 , at the koiwai farm .
although various exercise protocols were used in the 1st and 2nd years ( 1st to 4th surveys ) , the same exercise protocol was used from the 3rd to 5th years 
 ( 5th to 9th surveys ) .
w , walk ; t , trot ; c , canter ; and g , gallop .
two - yo , 2-year - old - horse ; three - yo , 3-year - old - horse ; and four - yo , 4-year - old - horse . cited 
 from a report by matsuba and shimamura .
pulse rate measured at the koiwai farm in 1931 ( july 29th  august 7th ) .
data obtained from each horse were plotted individually . cited from a report by 
 matsuba and shimamura .
it was showed that average body temperature rose from 38.1c to 39.5c from pre to post and returned to pre values within 2 hr after exercise .
they mentioned 
 that the temperature increase was larger for a canter than for a walk and trot and was larger during a canter of longer distance than for a shorter canter .
respiratory frequency ( rf ) was measured based on counting movements of the ribcage or the upper flank with the naked eye .
average rf increased from 12.4 
 breath / min at pre to 71.3 breath / min at post and decreased to 21.4 breath / min at 1 hr and 14.7 breath / min at 3 hr ( fig . 

the authors generated this graph using data from a table in a report by 
 matsuba and shimamura . ) .
they noted that because rf was very changeable just after exercise , rapid measurements would be required to accurately measure it . in 1944 ,
okabe and 
 sugiyama   measured rf continuously during exercise at a walk , trot , and canter by recording expiratory sound with a 
 microphone attached near a nostril and reported that rf immediately after exercise differed completely from rf during exercise because a very rapid decrease in rf 
 occurred just after finishing exercise .
the authors generated this graph using data from a table in a report by 
 matsuba and shimamura .
the mean pulse rate at pre was 33.4 beat / min and increased to 102.7 beat / min at post , after which it decreased to 39.6 
 beat / min at 1 hr after exercise and 34.4 beat / min at 3 hr after exercise ( fig .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura . ) .
although it was considered that heart rate ( hr ) measurement was preferable to that of pulse rate by auscultation , recording of electrocardiograms ( ecgs ) 
 of horses to calculate hr was impossible at that time , even at rest . moreover , although pulse rate immediately after exercise was also measured by auscultation , 
 because direct measurement of hr during exercise was impossible at the time , pulse rate immediately after exercise was considered to indicate hr during exercise . 

the first ecg recordings of horses in japan were carried out in 1944 by 
 yasuda et al . , and
the first ecg recording in the world of a horse during field exercise that 
 included fast galloping was carried out in 1964 by nomura et al .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura .
blood pressure was measured in these studies using the tycos sphygmomanometer at the point of the radial artery , and systolic pressure was recorded by measuring 
 pulses of the digital artery .
average blood pressure increased from 156 mmhg at pre to 238 mmhg at post and then decreased to 176 mmhg at 1 hr and 158 mmhg at 3 
 hr after exercise ( fig . 5fig .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura . ) .
it was noted that blood pressure increased even at lower intensity exercise , but the magnitude of the increase was much larger with higher intensity 
 exercise .
although the average value of 156 mmhg at pre was considered to be relatively high , it is unknown if the values had been converted to account for 
 hydrostatic pressure differences to the values at the height of the heart or not . considering the difference in height between the height of the radial artery and 
 the heart
, the reported values might be reasonable , even if the values were not converted .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura .
the average erythrocyte count at rest of thoroughbred racehorses was noted to be markedly higher than those of half - blooded horses .
erythrocyte counts increased 
 by about 2030% with exercise , and it returned to the pre value by 1 hr after exercise ( fig .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura . ) .
the average pcv at rest was approximately 40% and was higher than that of other types of horses .
pcv increased to about 50% at post and decreased to 
 almost the pre value 1 hr after exercise .
matsuba and shimamura speculated that one of the main reasons for these increases after exercise might be water loss 
 caused by exercise .
approximately 40 years later , the reason for these changes was clarified by persson et al . .
they performed splenectomies on standardbred trotting horses and found that the equine spleen can release erythrocyte - rich blood into the systemic 
 circulation during exercise , increasing the erythrocyte count and pcv .
the authors generated this graph using data from a table in a report by matsuba and 
 shimamura .
the average hemoglobin ( hb ) concentration at pre was 14.2 g / dl , increased to 20.0 g / dl at post , and then decreased gradually to 
 16.0 g / dl at 1 hr and 14.6 g / dl at 3 hr ( fig . 7fig .
7.changes in hemoglobin concentration ( [ hb ] ) at different times relative to exercise .
the authors generated this graph using data from a table in a report by 
 matsuba and shimamura . ) .
they stated that the reason for the increase in hb concentration was due to the increased erythrocyte count because hb exists inside of red blood cells . 

when blood viscosity was defined as its ratio to the viscosity of water ( water viscosity=1.000 ) , it was 5.06.0 at rest .
the average blood viscosity was 6.4 at 
 pre and increased to 10.6 with exercise , and returned to the pre value at 1 hr after exercise .
changes in hemoglobin concentration ( [ hb ] ) at different times relative to exercise .
the authors generated this graph using data from a table in a report by 
 matsuba and shimamura .
when matsuba and shimamura looked at all data on changes in variables induced by 
 exercise that were measured in a single horse during the first and second years of the study ( 1928 and 1929 ) , they noticed there was a tendency for many variables 
 measured in horses considered to be fitter to recover to their pre values more rapidly than those of other horses ; that is , it appeared that an excellent horse 
 could recover from fatigue caused by intense exercise more rapidly than other horses .
accordingly , they decided to evaluate the recovery status of each variable 
 by calculating the percentage of its pre value at different times during recovery . in the case of body temperature , when recovery state was evaluated , the numbers 
 used for calculation were the raw temperature data minus 30 , because the rate of increase in body temperature sometimes did not exceed 5% .
for the same reason , 
 data used for specific gravity of blood measurements were the raw data minus 1.000 .
as mentioned above , measurements of 20 variables were carried out a total of five times before exercise ( pre ) , just after exercise ( post ) , 1 hr after exercise ( 1 
 hr ) , 2 hr after exercise ( 2 hr ) , and 3 hr after exercise ( 3 hr ) .
later , the number of variables was decreased to 11 , as shown in table 3table 3.raw numbers and percentages for yamaougi in the 5th survey at the shimofusa imperial farm in march 1930examines itemraw numberpercentageprepost1 hr2 hr3 hrprepost1 hr2 hr3 hrbody temperature3838.738.438.438.6100.0108.8105.0105.0107.5respiratory rate1538262018100.0253.3173.3133.3130.0pulse rate3672413636100.0200.0113.9100.0100.0blood pressure164194174178174100.0118.4106.1108.5106.1specific gravity of blood1.0541.0541.0541.0301.054100.0100.0100.098.1100.0blood viscosity4.84.54.94.94.8100.093.8102.1102.1100.0[hemoglobin]9.510.510.610.09.7100.0109.7111.3104.8101.6erythrocyte count7,7609,4409,1768,7448,640100.0121.6118.2112.7111.3leukocyte count10,10010,90011,55010,55511,220100.0107.9114.4104.5111.1blood glucose10790909595100.084.184.189.089.0co2 concentration59.455.555.556.559.4100.093.493.495.1100.0percentages in boldfaced type indicate that the parameter recovered to 100  5% .
cited from a report by matsuba and shimamura .. the percentage of the pre value for each variable at 1 hr , 2 hr , and 3 hr was calculated .
when the percentage reached within 100  5% ( 95105% ) 
 compared with the pre value , the variable was considered to be recovered .
then the percentage of the total number of recovered variables at each time ( rr at 1 hr 
 [ rr@1hr ] , rr at 2 hr [ rr@2hr ] , and rr at 3 hr [ rr@3hr ] ; where rr is recovery rate ) was calculated , and an overall average was calculated from these ( ( rr@1hr + 
 rr@2hr + rr@3hr)/3 ) ) ; the authors proposed calling this overall average the  recovery rate  of each horse .
percentages in boldfaced type indicate that the parameter recovered to 100  5% . cited from a report by matsuba and shimamura .
they found a tendency for horses in good condition to have a lower increase in pulse rate after constant exercise , and the blood pressure of these horses tended 
 to be higher .
based on these observations , they thought that the d / p ratio ( where d is the blood pressure difference between pre and post and p is the pulse rate 
 difference between pre and post ) might become larger as training advanced .
they named the d / p ratio the  pulse pressure ratio  and considered that it might be a 
 valuable index for evaluating fitness of racehorses in future research .
additionally , measurement of pulse rate and blood pressure was thought to be useful 
 because they could be obtained noninvasively .
the recovery rate and d / p ratio were obtained from every horse for all surveys from the fifth through the ninth .
table 
 3 shows results from a single horse , yamaougi , collected during the fifth survey in march 1930 .
percentages in boldfaced type show that this variable had 
 recovered to within 100  5% .
as shown in table 4table 4.calculation of the recovery rate for yamaougi1 hr2 hr3 hrnumber of examined items111111number of recovered items375recovery rate0.270.640.45the recovery rate was 0.27 ( 3/11 ) at 1 hr , 0.64 ( 7/11 ) at 2 hr , and 0.45 ( 5/11 ) at 3 hr .
the authors generated this table using data from a table in a 
 report by matsuba and shimamura .
, the recovery rate was 0.27 ( 3/11 variables ) at 1 hr , 0.64 ( 7/11 ) at 2 hr and 0.45 ( 5/11 ) at 3 hr , and the overall average was 0.45 ( ( 0.27 + 0.64 + 
 0.45)/3 ) .
table 5table 5.summary of results of the 5th survey conducted during march 1930 at the shimofusa imperial farmnumbernamerecovery raterecovery rate at each timed / p1 hr2 hr3 hr1yamayoshi0.820.640.910.912.212yamanari0.700.730.730.642.163yamahisa0.640.550.730.641.814yamahide0.600.450.640.731.475yamataka0.580.550.640.551.736yamamichi0.580.450.550.731.527yamamune0.510.450.640.451.308yamanobu0.480.500.450.451.509yamaougi0.430.200.600.501.83d / p : ratio of d ( blood pressure difference between pre and post ) and p ( pulse rate difference between pre and post ) . cited from a report by matsuba and 
 shimamura .
the recovery rate was 0.27 ( 3/11 ) at 1 hr , 0.64 ( 7/11 ) at 2 hr , and 0.45 ( 5/11 ) at 3 hr .
the authors generated this table using data from a table in a 
 report by matsuba and shimamura .
d / p : ratio of d ( blood pressure difference between pre and post ) and p ( pulse rate difference between pre and post ) . cited from a report by matsuba and 
 shimamura . a follow - up survey was conducted on the relationship between recovery rate and racing performance of 25 horses whose records could be traced over their entire 
 racing careers .
a horse s winning percentage was selected as its index of performance , and the relationship between winning percentage and recovery rate was found 
 to be positively correlated ( fig . 8fig .
the authors generated this graph using data from a table in a report by matsuba and shimamura 
 . ) .
however , matusba and shimamura pointed out that although the recovery rate could indicate the fitness level and capacity for performance at the time when 
 the recovery rate was measured , because this index was obtained from a single measurement at the time a horse was 2 years old , recovery rate would not be 
 particularly useful for evaluating performance after a horse had undergone training and started racing .
it was recommended that it would be necessary to make 
 multiple recordings of the recovery rate in order to evaluate a horse s racing performance exactly . finally , they mentioned that since there are numerous factors 
 that can influence racing performance , it would be difficult to predict performance by using only the single variable of recovery rate .
they proposed that both 
 talent and training are important factors that have an influence on a horse s performance and emphasized the importance of training and of the need for research 
 on the effects of training .
the authors generated this graph using data from a table in a report by matsuba and shimamura 
 .
kimata , who was a student of matsuba , wrote interpretive articles in a journal for veterinarians on the exercise physiology of animals , which at that time was a 
 new concept in veterinary medicine . in those articles , he described in detail the effects 
 of exercise on body temperature , respiration , pulse rate , and blood temperature .
matsuba and shimamura established new methods for performance testing of racehorses and indicated that studies on the effects of training would become an 
 important area of research in the future .
accordingly , a series of experiments on the effects of training were conducted at the nakayama race club ( now nakayama 
 racecourse of the japan racing association ) over a total of four years . a research report entitled  studies on the performance and training of the racehorse  , 
 which contained results of those experiments ,
this report was a large book of 492 
 pages ( a5 size ) and mainly dealt with the effects of training ; the report covered physical changes of blood characteristics with training .
all of the results were 
 published as five papers in the journal of the central society for veterinary medicine in 1938 .
the series of experiments was carried out over a total of four years during the periods of 19331934 and 19361937 .
this project was carried out as 
 research commissioned by the teikoku keiba kyokai ( the imperial racing association ) .
although it had become possible to evaluate the performance of racehorses by using the new index , the recovery rate , 
 the study that introduced the recovery rate had been performed on 2-year - old racehorses trained on training farms , and the horses had not yet raced .
therefore , 
 matsuba decided to perform a series of experiments on racehorses trained at racecourses in order to better understand their exercise physiology and performance . 

however , he had been thinking that because it was not easy to evaluate performance even on training farms where it was possible to conduct standardized and 
 regulated exercise tests under controlled experimental conditions , it would be difficult to perform standardized exercise tests under nonexperimental situations , 
 e.g. , during actual training at a racecourse . accordingly , as the first experiment , he decided to evaluate the training method that racehorses actually used at the nakayama race club in order to understand 
 its effects on exercise physiological variables and create a database for future studies matsuba dubbed the training method that was being used at nakayama race 
 club  the present method of training  .
training was carried out from the end of july to the beginning of december in 1933 .
table 6table 6.feeding regimens in september at the nakayama race clubseptembermorningnooneveningnightoats ( g)630840840wheat bran ( g)220220220chaff ( g)2,2602,2602,260grass ( g)3,000salt ( g)22.622.622.6fresh forage ( g)15,000 ( per day)cited from a report by matsuba
horses were trained with practical methods and ran several times at speeds assumed 
 to be maximal during racing .
the first stage began on july 25th , and a maximal speed run was carried out on october 
 14th . in the second stage , which began on october 15th , after a short period of rest , training was carried out , and a maximal speed run was then conducted on 
 november 21st . in the third stage , which began on november 22nd , after a short period of rest ,
training was again started , and a maximal speed run was carried out 
 on december 9th .
table 7table 7.training protocol for a horse during the period of september to octobertrot ( m)canter ( m)total time ( sec)gallop ( m)total time ( sec)sep . 253,2001,600136263,2001,600136271,6001,600119282,4001,600136291,6001,600136301,6001,60013180052.3oct .
13,20022,40080013631,6001,60013641,6001,60011253,2001,60013661,6001,60012671,6001,60010883,20092,400800126101,6001,600126111,6001,600112123,2001,600136131,6001,600136141,6001,600108the authors generated this table using data from a table in a report by matsuba .
the distance of an intensive gallop workout was 1,600 m in most cases , and the time required to complete it 
 was 110 sec ; the horse s average speed was 14.5 m / sec ( 13.8 sec/200 m ) .
the canter 
 distance on a typical day was also 1,600 m , and its average speed was 11.111.7 m / sec ( 1718 sec/200 m ) , while the distance trotted was 1,6003,200 m. in general , 
 the distance trotted was longer and the distance cantered on a typical day was shorter compared with protocols used currently . cited from a report by matsuba .
the authors generated this table using data from a table in a report by matsuba .
five clinical variables ( body temperature , respiratory frequency , pulse rate , blood pressure , and cardiac sounds ) were measured once each week .
three variables 
 ( erythrocyte count , blood glucose concentration , and blood co2 concentration ) were measured about once every two weeks as an examination of blood 
 characteristics .
urine analysis included eleven variables ( color , turbidity , ph , specific gravity , viscosity , glucose concentration , protein concentration , 
 phosphoric acid concentration , total nitrogen concentration , creatinine concentration , and indican ) that were measured every 10 days .
six variables ( height , body 
 weight , chest circumference , cannon circumference , chest cross - sectional area , and cannon cross - sectional area ) were measured every two weeks during a physical 
 examination .
seven variables ( body temperature , respiratory frequency , pulse rate , blood pressure , erythrocyte count , blood glucose concentration , and blood 
 co2 concentration ) were measured four times at the time of mock races on september 30th , november 21st , november 28th , and december 9th .
the results of monitoring clinical variables that were ovserved with the progress of training were as follows : 1 ) body temperature was unchanged , 2 ) respiratory 
 frequency decreased , 3 ) pulse rate decreased , 4 ) blood pressure increased , and 5 ) cardiac sounds became clearer .
matsuba suggested that changes observed in pulse 
 rate , blood pressure , and cardiac sounds were related to improved cardiac function and that the decrease in pulse rate was associated with an increased stroke 
 volume .
in addition , because pulse rate was increased by a short period of rest from november 22nd , it was suggested that there would be interesting relationships 
 between training and pulse rate .
changes in blood variables with the progression of training were as follows : the erythrocyte count and blood glucose increased , and the blood co2 
 concentration initially increased but later decreased .
changes in urine variables occurred irregularly and appeared not to be useful as an index .
most variables 
 associated with the physical examination , including body weight , did not change during the training period .
changes in the recovery rate throughout the training 
 period were small , and in some cases , the recovery rate tended to decrease when training intensified due to conduct of maximal speed runs .
moreover , considerable 
 variability occurred in both the recovery rate and pulse pressure ratio .
matsuba suggested that the cause of these results was that the same exercise protocol was 
 not used .
based on these results , he concluded that the present method of training was not the optimal training method to improve racehorse performance and that 
 there was room for improvement .
the second experiment was performed by using a new training method that was a modified version of the present method of training .
matsuba named the training 
 method used for this study the  conservative method of training  .
four 2-year - old racehorses were studied , and training was conducted from april to october in 
 1934 .
the training intensity was lower and the trotting distance was shorter compared with the present method of training , and the training intensity was 
 gradually increased .
clinical , blood , urine , feces , and physical examinations were all performed once per week , and a performance test was conducted once every 
 two weeks .
the clinical , blood , and urine variables examined were identical to those in the previous experiment .
the summary of the results of this study was approximately the same as that for the previous study . because 
 respiratory frequency and pulse rate decreased and blood pressure increased , matsuba suggested that improvement in cardiovascular function occurred due to the 
 training . on the other hand , because the erythrocyte count and blood glucose concentration increased only slightly , but the blood co2 concentration did 
 not change , he concluded that blood characteristics may have properties that are not affected by excessive training . in this study , although the running distance and dates of the performance tests were designed to be held constant , it proved to be difficult to set a constant 
 running speed due to weather , track condition , and the occurrence of various diseases .
therefore , although variations in the results were observed , he concluded 
 that relatively constant data were obtained compared with the previous experiment .
however , since changes in the recovery rate and pulse pressure ratio were 
 small , he considered that there was no improvement in performance .
matsuba concluded that the training method used in this study was safe because all horses 
 finished the study able to participate in a race ; however , he considered this method was slightly inferior to the present method of training that was being used 
 and that future studies would be needed to evaluate positive effects of training on racehorse performance .
matsuba tried to use a similar protocol for the performance test to calculate the recovery rate , because the recovery status of each variable was largely 
 influenced by the exercise intensity of the performance test .
if the performance test was performed on only a single occasion on several horses to evaluate their 
 fitness at that time , it would be easy to set a constant exercise intensity for all the horses by making all the horses run simultaneously in the same group . 

however , when the effects of training on recovery rate were to be evaluated , the exercise intensities of the performance tests performed multiple times during the 
 training period would need to be set as identical .
moreover , in the field training study , it was 
 difficult to complete the entire training plan without any of the horses experiencing musculoskeletal disorders .
in addition , the number of horses matsuba used in 
 these studies was small . taking these factors into consideration
, the authors thought it unavoidable that the expected results were not obtained in these 
 experiments .
matsuba also evaluated the effects of administration of various kinds of medicaments on the performance of racehorses using four 2-year - old racehorses .
the training protocol used in this study was a modified version of the conservative method with the 
 trotting distance increased .
administration of nine medicaments ( 5% glucose , 3% calcium iodide , 20% benzoic acid locke s solution , radium ringer s solution , 
 oxygen inhalation , cam - phenal , vitacamphor , deigalen , and adrenalin locke s solution ) was performed , after which the effects of the drugs on running speed and 
 degree of recovery from fatigue were evaluated .
administration tests were carried out once per week from the middle of september to the end of october ( the first 
 and final tests were control tests ) .
for each treatment , the 5% recovery rate ( 100  5% ) , 10% recovery rate ( 100  10% ) , and pulse pressure ratio were 
 reported .
when evaluation was performed by using the 10% recovery rate , the best result was obtained with administration of 3% calcium iodide . however , because the 
 second - best result was obtained in the control tests , matsuba concluded that the recovery rate tended to decrease simply due to the administration of a 
 medicament . in terms of training regimens , because relatively good results were obtained by increasing the trotting distance , matsuba suggested that increasing 
 the trotting distance was more essential than increasing the canter distance . in the final experiment ,
changes in the blood s physical characteristics were investigated , and the utility of that information for use in regulating training 
 and evaluating performance was examined .
four racehorses ( 2 two - year -old , 1 five - year - old , and 1 six - year - old ) were studied .
training regimens used in this study were similar to the protocols used in previous experiments .
five clinical variables , twelve blood 
 variables ( erythrocyte count , maximal erythrocyte fragility , minimal erythrocyte fragility , specific gravity , viscosity , erythrocyte sedimentation rate ( esr ) , 
 pcv , freezing point depression , surface tension , ph , electrical conductivity , and blood co2 concentration ) , and seventeen urine variables were measured 
 once per week , and a fecal examination was also performed . because erythrocyte fragility , blood viscosity , esr , freezing point depression , and ph changed with the 
 progression of training , matsuba suggested that these five variables might be useful indices to study further in the future .
both the maximal and minimal 
 fragility of erythrocytes increased as training advanced ; furthermore , blood viscosity increased , and esr decreased as training progressed .
the relationships of 
 esr with training and condition were later followed up by sakurai , who had studied under matsuba .
the history of research on the exercise physiology of the horse in japan began in the 1920s during a time when the warhorse was still the major focus of equine 
 interest , and studies later began to be performed that were focused on racehorses .
matsuba and shimamura of the university of tokyo played major roles in 
 initiating studies of racehorses during the 1930s .
their first study , published in 1933 , was the single most important 
 study ever published in the field of equine exercise physiology in japan .
it is remarkable that they were doing research to evaluate performance of racehorses in 
 the 1930s at the dawning of the era of modern horse racing in japan .
another interesting point about their study is that data were collected from elite thoroughbred racehorses such as wakataka , the winner of the first japanese 
 derby held in 1932 at meguro racecourse .
wakataka won seven of 11 races in which he ran , including the emperor s cup in the autumn of 1932 at meguro racecourse . 

in addition to wakataka , data were collected from a number of elite racehorses : happy chapel , winner of the emperor s cup in the spring meeting at meguro 
 racecourse in 1932 ; hakusetsu , winner of the emperor s cup in the autumn meeting at yokohama racecourse in 1933 ; and ascot , winner of the emperor s cup in the 
 spring meeting at meguro racecourse in 1933 .
later , ascot participated in eventing at the berlin olympics in 1936 with baron nishi , who was the gold medalist in 
 individual show jumping at the los angeles olympics in 1932 .
data have also been collected from several contemporary japanese derby winners such as tanino gimlet 
 ( 69th derby in 2002 ) , deep impact ( 72nd derby in 2005 ) , meisho samson ( 73rd derby in 2006 ) , and logi universe ( 76th derby in 2009 ) , making it all the more 
 remarkable to realize that detailed data from the first winner of the japanese derby had been measured . in recent times , it has become possible to measure cardiopulmonary functions during exercise , such as oxygen uptake , carbon dioxide production , minute 
 ventilation , cardiac output , blood gases , and blood pressures , due to the introduction of equine high - speed treadmills and flow - through gas collection systems . 

these technological advances have been used for measuring oxygen uptake since 1992 and for evaluating the effects of training on the oxygen transport system , 
 cardiopulmonary function [ 1,2,3,4 , 32 ] , and skeletal muscle [ 26 , 49 , 50 ] . at the present time ,
one of a number of variables that have been measured in field exercise tests , the v200 ( running speed at which the hr reaches 200 beat / min ) 
 of numerous young horses trained at training farms has been recorded several times during their training periods [ 5 , 33 , 34 ] , and the data indicate that this variable may be useful for evaluating fitness 
 and the effects of training .
however , it has been impossible to predict future racing performance using only this variable .
when the values for the variable 
 vhrmax ( running speed at maximal hr ) measured in jra racehorses were compared , it was found that stronger horses ( open class in the jra classification ) had higher 
 vhrmax values than other horses ( newcomer or maiden class ) .
however , it was still impossible to determine the 
 performance of a racehorse by using only this variable .
even if maximal oxygen uptake , the best indicator of aerobic work capacity of a racehorse , was measured , 
 it would still not be possible to predict overall performance .
the pioneering work of matsuba and shimamura created a legacy that continues today as researchers 
 attempt to better understand the factors that determine , and might be used to predict , racehorse performance .
 abstractthe history of research on the exercise physiology of racehorses in japan dates back to the 1930s . a research report entitled  studies on exercise physiology 
 and performance testing of the racehorse  
 , published in 1933 by shigeo matsuba and torao shimamura of the university of tokyo , was epoch - making and the most 
 important study in the history of equine exercise physiology in japan . 
 research results were reported from 92 thoroughbred racehorses in a large - scale project 
 during the period of 1928 to 1932 at the shimofusa imperial farm and the koiwai farm , which were the two greatest racehorse farms at that time . 
 a total of 20 
 physiological variables were measured to evaluate the fitness of thoroughbred racehorses before exercise ( pre ) , just after exercise ( post ) , 1 hr after exercise 
 ( 1 hr ) , 2 hr after exercise ( 2 hr ) , and 3 hr after exercise ( 3 hr ) in order to calculate their recovery rates as an index of fitness and performance . 
 the 
 percentage of the pre value at 1 hr , 2 hr , and 3 hr was calculated . 
 when the percentage of a variable reached 95105% of the pre value , the variable was 
 considered to be recovered . 
 the percentage of the total number of variables that were recovered for each time period was calculated , and an overall average was 
 calculated from them ; matsuba and shimamura proposed calling this overall average the  recovery rate  , which could then be applied to evaluate each horse . 
 the 
 effects of training on racehorses were subsequently evaluated by measuring the various physiological variables and the recovery rate . 
Exercise Physiology of the Racehorse
Performance Testing Using Recovery Rate as an Index
Effect of Training on Performance of the Racehorse
Conclusions