Healthsaving Technologies for Young Cross Country Skiers

Cardiovascular System Testing for Sport Training Program Design

Anna Zakharova, Natalia Tarbeeva, Alena Tarbeeva and Tatiana Miasnikova

Institute of Physical Education, Sport and Youth Policy, Ural Federal University, Mira Street, Ekaterinburg, Russia

Keywords: Cardiovascular System, Hemodynamic Indicators, Training Process, Training and Testing, Cross Country

Skiers.

Abstract: Training process in sport imposes high demands on athletes’ cardiovascular system. Results of incremental

treadmill test revealed that young athletes perform intensive physical work with cardio strain, i.e. at high HR.

That is why training for cardiac adaptation should be foreground at the initial stages of sport specialization.

Hemodynamic monitoring allows assessing cardiovascular system dynamics in training. The analysis of such

indicators as HR, SV, EDV and inotropy (heart contractility) in 30 12-14 year-old cross-country skiers made

it possible to divide them into 3 groups with different training orientation. Group 1 (low aerobic fitness: SV<

70 ml, EDV<110 ml) underwent aerobic training and general exercises. For group 2 (moderate fitness with

high inotropy: RHR< 65 bpm, SV>70 ml, EDV >110, inotropy > 45) general and specific exercises were used

on cross-country terrain under HR control (upper limit is 160 bpm). Group 3 (moderate fitness with normal

inotropy less than 40%) underwent intermittent training as well. Regular hemodynamic monitoring (once per

3 months) helped individualize training, transferring athletes from one group to another according to the

monitoring results obtained, thus avoiding inadequate cardiac adaptation. Incremental tests carried out twice

a year proved the effectiveness of the selected health-saving technologies.

1 INTRODUCTION

Cross country skiing is a demanding sport. The skiing

and running workouts take place in mounting terrain

that increase demands on an athlete’s cardio

respiratory system. Modern adolescents differ from

previous century teenagers. In the XX

century we

had to do a lot of house and garden work, walked a

lot instead of going by car and played outdoors rather

than computer games, thus developing our endurance.

Back in those times starting cross-country skiing at

the age of 13 and even 18 might lead to being an

Olympic champion because of routine background

endurance and strength. Nowadays comfortable and

physically inactive childhood limit the cardiovascular

fitness at early ages. As a result the children start sport

training with insufficient level of endurance.

Therefore young athletes can hardly sustain a training

load that is too intensive for a weak heart. Too

intensive physical work at early ages disrupts the

regulatory systems interaction and leads to irrational

cardio adaptation.

An analysis of the scientific literature revealed

that at present the typical planning of the training

process does not take into account the young athlete’s

individual characteristics, morphological and

functional development and current condition.

Recommendations for planning training during the

period of initial sport specialization contain

approximate annual training loads and the ratio of

loads of various intensity and specialities, and the

coach is recommended to take into account the

adolescents’ individual characteristics judging by

their appearance and level of their physical

capabilities. No specific criteria are offered for

assessing a child’s morphofunctional development.

The situation is redoubled at puberty: the quick

muscles development upsets the “heart-muscle

balance” challenging their heart and cardiovascular

system. So during the puberty period it is necessary

to determine the volume and, what is more important,

its intensity in order to save the heart muscle for the

sport career in adulthood and for a happy life after

abandoning the sport career. That is why the aim of

our research was to determine the testing technologies

that may serve as the basic for designing a training

program.

Zakharova, A., Tarbeeva, N., Tarbeeva, A. and Miasnikova, T..

Healthsaving Technologies for Young Cross Country Skiers - Cardiovascular System Testing for Sport Training Program Design.

In Proceedings of the 3rd International Congress on Sport Sciences Research and Technology Support (icSPORTS 2015), pages 139-144

ISBN: 978-989-758-159-5

139

2 ORGANIZATION AND

METHODS

Subjects. A group of 30 young cross-country skiers

(19 males and 11 females) 12-14 years old who had

1-3 years of training experience in skiing participated

in the study. The participants of the experiment had

14 hours of training a week.

Research Design. We assumed that there were

subjects with different morphofunctional state. To

divide them into different training groups with similar

morphofunctions, the initial measurement of athletes’

hemodynamics was taken in April, 2013. The current

research was carried out from April 2013 to May

2015 with several experimental tests including

athletes’ hemodynamics measurements and

incremental treadmill test (Table 1).

Incremental Test. The incremental test protocol was

not less than 5 stages jogging. It was held without a

preliminary warm-up on a treadmill (Technogym,

Italy) whose design allows adjusting the running

speed up to 25 km h

-1

. The initial speed was 4 km h

-1

The duration of each stage was 2 minutes. The speed

of the treadmill was increased by 2 km h

-1

for each

subsequent stage up to the last stage to exhaustion in

order to determine the maximal running speed. Heart

rate monitoring with Garmin Forerunner 305

(Garmin, USA) was used during the test and 5

minutes after it for recovery recording.

2.1 Heart Rate Monitoring during

Incremental Test

The running incremental test is one of the most

accessible and informative tests to assess physical

fitness in cyclical kinds of sport (cross-country

skiing, speed skating, cycling, track-and-field, etc).

The idea of the incremental test is to match the

changing athlete’s heart rate with the intensity (speed

or power) of physical load.

The heart rate monitoring was carried out with

Garmin Forerunner 305 for recording current HR

during the test and recovery. For rapid test results

processing an interval workout was created in

advance in Forerunner 305. The current values of HR,

the duration of interval stage were demonstrated on

the screen and saved in Forerunner 305 memory.

In an ideal athlete the “speed-heart rate” plot

yields a straight line. But in real athletes this curve

has a different form. The analysis of the peculiarities

of the graph “jogging speed ̶ HR” location and its

trajectory (figure 1) allows you determining:

- HR

4km h

-1

which is the athlete’s heart rate while

jogging at a speed equal to 4 km h

-1

, corresponds

to the athlete’s aerobic system development.

There is a heart rate plateau on the graph the value

of which is taken as the HR

4km h-1

indicator;

- the slope of the curve in the interval between the

speed of 4 km h

-1

and 6 km h

-1

indicates the cardio-

vascular system potential. The smaller the angular

inclination of a line drawn through the point HR

km h

-1

and HR

6 km h

-1

, the higher the heart potential

to deliver oxygen to muscles is. The extrapolation

of this line (when HR is within 90 and 120 beats

min

-1

) until the intersection with isoline HR = 190

beats/min shows the speed at which the athlete

could run if for achieving high running speed he

(she) used only their cardiovascular system

(without muscles recruitment). This allows

determining the potential capabilities of the heart

to deliver oxygen to muscles;

- running speed at a heart rate 170 beats min

-1

, km

-1

used as physical working capacity indicator

similar to PWC

170

(Belotserkovsky, 2005) or

PWC 170 – Cycle test, the primary purpose of the

which (Cambell et al., 2001) is to predict the

power output at a projected heart rate of 170 beats

per minute (bpm). For example, one athlete has 16

km h

-1

at the HR =170 bpm while the other has

only 13.5 km/h. The former is more physically fit

than the latter;

- jogging time with HR below 170 bpm

corresponds to the athlete’s aerobic fitness: the

longer an athlete has run with heart rate below 170

bpm the better is the current state of the athlete’s

aerobic system;

- time of physical work at HR above 180 bpm is

used as an indicator of the development of the

muscular system on cardiovascular system: the

longer the athlete is able to perform high intensity

workload the stronger is their muscular system;

Table 1: Experiment schedule design.

April July October January April

Incremental treadmill test * * *

Hemodynamic monitoring * * * * *

The training focus selection * * * * *

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Figure 1: A young skier’s, 13 years old, (thick line) and a skilled skier’s, 24 years old, (thin line) pulsograms.

- V

max

is the maximal speed the athlete could reach.

It characterizes an athlete’s integral readiness in

jogging;

- HR

max

is an indicator of the priority in the

cardiovascular or muscle fitness: if HR

max

is lower

than 180 bpm, then there is cardiovascular

priority. And there is a priority in the muscular

system “heart-muscle balance” if HR

max

is higher

than 200 bpm.

The last three indicators allow us to determine the

limiting factors of athletes’ performance (Seluyanov,

2002). According to modern concepts in cyclic sports,

physical performance qualifiers can be largely limited

by either cardiorespiratory (cardiovascular) system or

muscular system.

2.2 Hemodynamic Measurements

The hemodynamic monitor MARG 10-01

"MicroLux" (Chelyabinsk, Russia) is usually used in

emergency and operation rooms. The device

functioning is based on such noninvasive methods of

hemodynamic monitoring as impedance

cardiography and spectrophotometry,

electrocardiogram monitoring (ECG), pulse oximetry

monitoring, reography and central hemodynamics

monitoring, blood pressure and temperature.

Measuring Methods. For the experiment a patient

(athlete) was in supine position. Before recording all

subjects were at rest in supine position during 10

minutes. All measured indicators of the central

hemodynamics were automatically registered with 8

pregelled ECG electrodes Ag/AgC by MicroLux

software with beat-to-beat record.

Hemodynamics is described by four general

indicators: volemia, inotropy, vascular tone,

chronotropy. The above-mentioned indicators are

shown on the monitor as a percentage of normal

values. The deviations of more than 25% are

considered too high/low for adult.

Central hemodynamic indicators are presented in

four groups: perfusion (stroke volume, cardiac

output, stroke index, cardiac index), preload (end-

diastolic volume, end-diastolic index), afterload (the

index of total peripheral resistance, stroke index of

total peripheral resistance), contractility and left

ventricular activity (contractility index, ejection

fraction; index of left ventricle activity, stroke index

of left ventricle activity).

To investigate the young athletes’ functional state

we chose the most informative for cross-country

skiing hemodynamic indicators.

Heart rate (HR) is the most accessible and

informative indicator of the athletes’

cardiorespiratory system development.

The stroke volume (SV) values should be a

reference point in examining athletes in endurance

sport.

Cardiac output (CO) is the indicator of cardiac

systolic function and is equal to HR multiplied by SV.

Increasing SV and CO during long term exercise is

one of the main effects of endurance training. At the

same time the growth of CO should occur due to SV

rise, but not due to heart rate rise.

End diastolic volume provides sufficient stroke

volume and cardiac output and is the guarantor of

good tolerance for high-intensity work load in train-

Healthsaving Technologies for Young Cross Country Skiers - Cardiovascular System Testing for Sport Training Program Design

141

ing and competitive activities.

An ejection fraction changes from 57 to 65 and

serves as an indicator of fitness level as well as the

intensity of the previous training process.

3 RESULTS

The graphical displays of research subjects’ heart rate

values showed that all research participants have

insufficient development of the cardiovascular

system to perform intense workouts. Figure 3 features

the HR graphical displays of one of the participants

in the experiment (13 years old) and skilled skier (24

years old). It shows the difference in the development

of the cardiovascular system and the dynamics of HR

during the incremental treadmill test. According to

the graphs, the same physical load (jogging speed)

generates different response in the athletes, and they

performed in different zones of intensity (figure 1,

table 2). In this case higher values of HR during

intensive load are explained by higher initial heart

rate of the younger skier (table 2).

Table 2: Incremental treadmill test indicators in young (1)

and experienced (2) cross-country skiers.

Indicator 1 2

HR at rest, bpm 69 ± 5 55 ± 3

4km h-1

128 76

170 b

km h

-1

8 18

HR<170 b

, min:sec 5:10 13:40

HR>180 b

, min:sec 7:50 2:05

max

, km h

-1

18 22

max

, bmp 196 187

Initial measurement and evaluation of athletes’

hemodynamic indicators showed that the values of

hemodynamic indicators in the participants were

within age norms (Baranov and Scheplyagina, 2006;

Diatlov et al., 2005; Zotova et al., 2012) or better

(higher or lower than normal, depending on trends in

age-related changes in endurance training), with the

exception of inotropy. Namely, it was revealed that:

 HR indicators were within the age limits in 10

subjects and below normal in 20 subjects;

 SV indicators were within the age limits in 21

subjects and above normal in 9 subjects;

 EDV indicators were within the age limits in 19

subjects and above normal in 11 of them;

 inotropy exceeded adult norm (25%) by more than

20 % in 22 young subjects, less than 20% in 8

subjects.

Inotropy is described as the force of heart contraction

and it varies depending on the training process

intensity: the more intensive work in the training

cycle is, the higher the inotropy value. Inotropy in

research participants varies from 30 to 60% (the age

norm is 30%). High values of inotropy are usually the

result of exposure to a high intensity load that can lead

to irrational adaptation of a child’s heart (without an

end-diastolic volume and ejection fraction increase)

and overstrain. Young 12-13 year-old skiers have

little sport training experience and, as a rule,

increased resting heart rate (RHR). Therefore any

workout of cross-country training is intense for them.

The initial hemodynamic research in April 2013

and the analysis of such indicators as HR, SV, EDV

and inotropy (heart contractility) in 30 young cross-

country skiers 12-14 years old made it possible to

divide them into 3 groups (table 3):

 Group №1 included athletes who had low aerobic

fitness levels: SV < 70 ml, EDV < 110 ml, high

RHR and inotropy;

 Group №2 was composed of moderately trained

young skiers (RHR < 65 bpm, SV > 70 ml, EDV

> 110) with high inotropy (inotropy > 45%);

 Group №3 also had moderate fitness level athletes

with normal inotropy (not more than 40%).

Different training groups had various focuses in

further training taking into account the results of

initial hemodynamics research (table 4).

For athletes of group №1 it was recommended to

limit physical work causing HR rise higher than 160

bpm. For adolescences with resting HR about 80 bpm

it is not difficult to overcome this heart rate limit. That

is why uphill terrain skiing and jogging were

excluded from their workouts. Aerobic training was

essential for group №1 in order to improve

cardiovascular fitness.

We called subjects “moderately trained” meaning

“moderate” in comparison with skilled athletes but

they had very good hemodynamic indicators and

fitness level for 12-14 year-old adolescents. The only

problem in hemodynamics in group №2 and 3 is high

values of inotropy.

For cross country skiers from group №2 general

and specific exercises were used on cross-country

terrain under HR control (upper limit is 160 bpm).

This was done to avoid excess strain in cardiovascular

system.

Group №3 underwent interval training along with

aerobic training. The volume of training load for all

groups was selected according to age, sex and period

of training.

After 3 months of training the second

hemodynamic research was carried out. According to

the results of hemodynamics monitoring, the groups

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Table 3: Hemodynamics criteria for 12-14 year-old cross-country skiers group forming (in supine at rest).

Training groups HR, beats/min SV, ml EDV, ml Inotropy, %

Age norm 72-82 60-80 80-120 30-40

Group №1

(10 people)

70±5

lower limit of norm

65±6

norm

105±9

norm

55±10

above norm

Group №2

(12 people)

62±4

below norm

76±8

upper limit of norm

115±8

norm

54±9

more than 20% above norm

Group №3

(8 people)

60±5

below norm

85±6

above norm

132±11

above norm

35±7

norm

Table 4: The focus of the training in groups.

Training group Training focus Basic exercises Basic methods

Group №1 Aerobic

Overall physical training (total body strength training), sport walking,

cycling, sport games, skiing on flat terrain

game like method, uniform

(steady)

Group №2 Aerobic Running, skiing simulations, skiing on uphill terrain Uniform

Group №3

Aerobic and

anaerobic

Running, skiing simulations, roller skiing, cross-country skiing Uniform, repeated

were reformed within group criteria (table 3). If group

№3 athlete’s inotropy is high, the athlete is

transferred to training group № 2. The training focus

was readjusted for him (her). With the inotropy value

decreasing below 40% and the growth of EDV an

athlete from group №2 was enrolled into training

group № 3. Thus, such process of hemodynamic

monitoring took place regularly (once in 3 months)

and resulted in changing the group number and

training focus correspondingly.

An example of the experiment participant’s

hemodynamics changes during the year is shown in

table 5.

The incremental treadmill test with heart rate

monitoring conducted twice a year determined

positive training effects of the experimental training

focus selection. Figure 2 shows pulsograms of a cross

country skier at the beginning and at the end of the

experiment.

Table 5: Year changes of an athlete’s hemodynamic

indicators.

Indicators

April

2014

July

2014

October

2014

January

2015

April

2015

EDV, ml 100 109 112 115 125

HR, beats/min 68 66 62 65 63

SV, ml 64 66 70 78 81

Inotropy, % 51 40 38 45 41

Training group № 2 № 3 № 3 № 2 № 2

The data presented in figure 2 show that the

physical work performed in the course of the

experiment, led to a heart rate decrease at a speed of

4 km h-1, an increase in running speed at heart rate

170 bpm, an increase in the maximum running speed

(table 6), thus indicating the growth of aerobic and

muscular fitness.

Table 6: Incremental treadmill test indicators in young

cross-country skier before (1) and after (2) the experiment.

Indicator 1 2

HR at rest, bpm 70 ± 3 61 ± 2

4km h-1

135 113

170 b

km h

-1

12 14

HR<170 b

, min:sec 8:15 10:50

HR>180 b

, min:sec 4:50 2:15

max

, km h

-1

18 20

max

, bmp 193 187

All the measured indicators of the young athlete

became close to those of the experienced cross-

country skier (table 2).

The analysis of the experiment results shows that

at the stage of initial sports specialization the focus of

the training process, as well as the means and

methods of training, were properly selected and

adjusted. As a result, the projected adaptation

processes occurred in the athlete’s body. The

experimental planning focused on proper adaptation

of athletes’ cardiovascular system at the stage of

initial sports specialization allowed:

1. Reducing inotropy to below 40% (i.e. by 10-

15%).

2. Increasing SV by 15-30 ml by means of EDV

increase by 20-30 ml.

3. Reducing resting heart rate by 5-15 bpm.

Thus, at end of the experiment there were no athletes

in group №1: all cross-country skiers with low

aerobic fitness improved their fitness and skiing

performance. These results suggest purposeful car-

Healthsaving Technologies for Young Cross Country Skiers - Cardiovascular System Testing for Sport Training Program Design

143

Figure 2: Pulsograms before (line 1) and after (line 2) the research.

diovascular development of 12-14 year-old cross-

country skiers thanks to experimental planning of the

training.

Such individualization of the training process at

the stage of initial sports specialization is a health-

saving technology that can be widely applied in youth

sport. The data obtained can be used to optimize the

development of athletes’ cardiovascular system and

will prevent overtraining and the disruption of

adaptation processes in athletes. The knowledge of

the relationship between HR, SV, EDV and inotropy

allows providing health savings and successful

preparation of sports resources.

4 CONCLUSIONS

1. Hemodynamic monitoring reveals the indicators

of athlete’s cardiovascular development (HR, SV,

EDV, inotropy) and their readiness to perform

demanding physical work in sport.

2. The account of hemodynamic indicators serves as

the theoretical basic for differentiated training in

youth sport. It allows influencing the cardiac

development purposely and selectively, thus

ensuring the athletes’ health, performance

improvement, especially in adolescence.

ACKNOWLEDGEMENTS

The work was supported by Act 211 Government of

the Russian Federation, contract № 02.A03.21.0006.

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