Laskesuusatamise lasketäpsuse sõltuvus lasu hetkel vaadeltavatest parameetritest

Submitted in August, 2002

Knowledge of proper shooting rhythm and heart rate (HR) parameters at the moment of shot, as well as the level

of relaxation rate (RLX), are of essential importance for improvement of shooting performance in the biathlon. We

searched for relations between the selected parameters, characteristic for continuous recovery processes, and

shooting accuracy, by means of simulation of various levels of heart rate in cross-country skiing in one selected

female biathlon competitor. Results of our research confirm that the shooting success of biathlon competitors may

be forecast to a certain extent on the basis of observation of those parameters. Shooting success has improved,

based upon shooting rhythm feedback, and determination of the optimum range of heart rate variability.

The achievement of top sports performance in the

biathlon is conditioned by demonstration of various

specific abilities and skills. Each athlete must know

how to optimally distribute his/her power and strength

in order to achieve maximum output in both crosscountry

skiing and shooting. Demands put on an

athlete.s motor, physiological, and psychological abilities

by biathlon sports performance have been characterised

by several authors (Fencl, 1979; Kryl, 1979, 1987;

Ho.ek, 1979; Mundil, 1984; Lou.ecký et al., 1985;

Vojti.ek, 1985 abc; Brych, 1985; Petroviè, 1988;

Nitzsche, 1988; Ondráèek, 1995; Paugschová, 2000).

Reduction of time spent on the shooting range was

also indicated as an option of how to achieve higher

quality of results in shooting. Ka.per (1976); Dunayev

& Dokutchayev (1981) ascertained, that the shooting

of highly trained competitors is not negatively affected

by a shorter time of preparation for as well as quick

execution of shots. In consideration of the new structure

of the Anschutz Bi-7 gun, the previously published

intervals of 7.8 seconds between individual shots

are considerably shorter now.

Results of the research of heart rate (HR) and

breath rate (DR) effects on shooting performance

were summed up by Foøt (1979, 1983) as follows:

1. The shooting success of highly trained biathlonists

is not dependent on heart rate. During the first shot,

the heart rate (HR) is kept within 130.170 beats

per min, depending on the athlete.s state of health

and readiness, effort exerted in the race, and the

character of the ground in front of the shooting

range. Then the heart rate gradually falls down to

110.140 beats per min. during the last shot.

2. Shooting success is affected by both the apnoea

interval and the interval between individual shots.

Intervals of 4.6 seconds between individual shots,

and apnoea intervals of 1.5.2.5 seconds before each

shot are considered optimum. In most cases, shooting

becomes unsuccessful if this stereotype has

been impaired. The shortest reported interval of

2.5 seconds between two shots is connected with

an exceptional level of the competitor.s conditioning.

The nineteen year old candidate Z. H. meets all

prerequisites to become a member of the Slovak women

team soon. Her biggest sports achievement was

placement in the 2002 European Championships in

Kontiolahti, Finland, from which she gained two silver

medals.

Observation of her shooting took place in the shooting

range Osrblie which meets the strict parameters

of the International Biathlon Union (IBU). She was

shooting at electronically driven Hora 2000 brand targets

from a 50 m distance. Analysis of her shooting

with training load simulation on different levels of

intensity was carried out during two training sessions

with a time difference of 28 days. Z. H. always ran

a 500 m circle first, and then executed a series of five

shots, two times from the prone position and two

times from a standing position, after reaching about

the scheduled levels of heart rate of about 100 beats

8 Acta Univ. Palacki. Olomuc., Gymn.

per min, 130 beats per min, 160 beats per min, and

max HR per min. Her racing heart rate was analysed

during two runs in pursuit races (shot series performed

two times in the prone and two times in the standing

position) which took place within the Slovak Cup.

From racing heart rate records (R-R intervals data),

only the results of one shot series in the prone and

standing positions could be included in calculations,

given the total capacity of memory of the sport tester

used . Polar VANTAGE NV Heart Rate Monitor. So

we obtained a total of 180 records of individual shots

(n = 180).

The success rate of individual shots according to

their order was analysed on the basis of ten measurements

during the several following practices (n = 250

shots in the prone position, and 250 shots in the standing

position), i. e. 10 repeated measurements of 5-shot

series performed in both prone and standing positions

at five levels of heart rate.

The competitor was instructed to turn the Heart

Rate Monitor on always at the specified place, about

1 minute before shooting, and to turn it off about

10 seconds after the last shot. She always pressed the

button of the HR record interval to inform us about

her arrival at the shooting point. After each shooting

item, she took a 1 minute rest. Each section run at

a higher heart rate was always preceded by a 3 minute

break. This time was usually used by the competitor

for gun reloading. If possible, examinations took place

under standard weather conditions, such as calm and

sunny with an air temperature of about 0 to ±2 °C.

The issue of the accurate shot moment determination

was solved by means of shooting trainer and sport

tester/monitor synchronisation under laboratory conditions.

It has been ascertained that the shot was always

released on the top of the R-R interval curve (pulse by

pulse).

Correlation between the observed shooting parameters

and the success rate was assessed with the help of

1970). Shooting performance was assessed from the

viewpoint of shooting in the prone position, in the

standing position, and in the both prone and standing

positions.

R-R intervals data recorded during the race show

that in biathlon, there are no doubts about the connection

between the highest heart rate oscillation and

variability, and shooting (Fig. 1). In this case, the

probationer.s heart rate did not fall under 170 beats

per min even during long downhill runs. Also a systematic

racing load monitoring is useful for our purposes,

as it allows us to re-analyse the sports performance,

and then to correct the training load in individual

heart rate bands. The individual search for optimum

solution of motor tasks in the biathlon is connected

with both skiing within the relevant heart rate band,

and immediate preparation for and execution of shooting.

As to skiing, it is enough to monitor heart rate

changes. Heart rate variability assessment and search

for its relation to the following shooting is, however,

impracticable. Heart rate variability has been considerably

reduced under the continuous motor load, or

after the load with insufficient relaxation intervals

(0.4 ms).

Therefore, our research was mainly aimed at selected

parameters, hypothetically determining the accuracy

of shooting as late as in the moment of the

individual shot.s delivery.

An important condition of successful shooting in

the biathlon is the ability to synchronise shooting with

one.s heart rate. Heart rate drop occurs at the end of

energy exhalation (expiration) upon finishing preparation

for shooting, while the probability of shot

occurrence in the diastolic interval between two systoles

grows. Heart rate drop relates, however, to only several

heart contractions.

On the basis of detailed shooting analysis under

laboratory conditions and then in the field, it has been

ascertained that Z. H. shows a highly developed autoregulatory

system of driving mechanisms of the body,

significant for target behaviour achievement. By

Record of heart rate course during the race (R-R intervals)

gradual improvement of this system, this competitor

has learned how to appropriately direct her breathing,

cardiovascular system, and state of mind while shooting

to such an extent that she can push the trigger

exactly at the moment of reaching the lowest value of

her heart rate, or the highest values of R-R intervals

(Fig. 2). Software Polar Precision Performance (1998)

also offers a graphical record of heart rate curve on

the basis of individual R-R interval duration in miliseconds.

It can be said that the competitor has reached

the state of the relatively highest degree of relaxation

in the moment of the shot. Repeated shots nearly

always occur at the highest point of the R-R interval

curve, at which the relatively highest values of heart

rate variability have also been recorded.

The hierarchy (significance) of certain individual

factors relating to shooting success rate has been determined

by means of pair correlation analysis (TABLE 1).

We observed the dependence of shooting success on

R-R (1) interval (arithmetical mean of two values

closest to the shot), R-R (2) average interval (from

of standard deviations of the last 8 values of R-R

intervals before the shot, considered an indicator of

heart rate variability). We have also searched for relations

between the time lapsed (shooting rhythm . the

fourth independent variable) between arrival at the

shooting success rate. The shooting rhythm calculation

provided for the standard deviation of individual

time intervals, considering the total success rate of

five-shot items. With the option of a high number of

shots (n = 180), all those correlation coefficients

appeared to be significant at a 1 % level of statistical

importance. From the material point of view, however,

the share of individual figures in explanation of

shooting success fluctuation is relatively small. The

highest correlation coefficient was found between the

time interval from arrival at the shooting point to the

1st, 2nd, 3rd, 4th and 5th shot, and shooting accuracy

By means of a more detailed analysis of success

rate with individual shots (according to the order of

5 shots in one shooting item R (2), it has been ascertained

that the highest number of inaccurate hits by

Z. H. refer to the first and the last shots in the prone

position, and to the last shot in the standing position

(TABLE 2, 3). The tables were set up on the basis of

results of ten repeated examinations where the candidate

was shooting only one series of five shots in the

prone position, and one series of five shots in the

standing position at each of the five simulated heart

rate levels after the run. Shooting success at a racing

heart rate was assessed during 10 speed races.

Course of R-R interval duration with marked shot moments (pulse by pulse)

Coefficients of correlation between the observed parameters and shooting accuracy at the moment of the shot

Success rate of individual shots according to their order

Shooting in the standing position (total 250 shots)

attention to whether she hit the target or not, but

concentrate on the activity itself until the very end.

Shot assessment may take place as late as on departure

from the shooting range. On the basis of the

competitor.s heart rate records and variability during

the last shot, it has been ascertained that Z. H., often

subconsciously dealing with her departure from the

shooting range, was not concentrated enough on the

last shot and thus obtained forfeit points in vain.

Results of the observation of this top female

biathlon competitor show that in most cases, she is

able to push the trigger in the moment of top relaxation

due to her auto-regulatory system activation.

Significance of knowledge of heart rate changes and

variability with respect to shooting accuracy was confirmed

in part. From all the observed parameters,

however, shooting accuracy is determined by proper

shooting rhythm observation from arrival at the shooting

by R-R intervals fluctuation and heart rate variability.

The suggested diagnostic procedure of R-R intervals

monitoring allowed certain errors in shooting,

made by the observed competitor, to be revealed to

observers. They include irregular shooting rhythm,

overly long preparation time for shooting, imperfect

concentration till the last shot, causing inaccuracy of

any of the shots performed in the both standing and

prone positions. In respect of improvement of training

process management, especially in the field of top

sports, knowledge of factors determining the sports

performance of the particular individual is considered

rather important. It is certain that shooting practice

aimed at the elimination of indicated mistakes made

by the observed competitor will speed up the improvement

of her performance.

Klub biatlonu Osrblie

976 45 Hronec

Slovakia

Prof. PaedDr. Roman Moravec, CSc.

Comenius University

Faculty of Physical Education and Sports

Nábr. arm. gen. L. Svobodu 9

814 69 Bratislava

Slovakia