Assessment of Physical Working Capacity of Combat Horting Athletes of Different Qualification Levels Using the PWC170 Test

The functional test based on determining the level of muscular workload at which heart rate increases to 170 beats per minute is known as the Sjöstrand test or the PWC170 test (derived from the English term Physical Working Capacity).

Assessment of physical working capacity using the PWC170 test is based on two established physiological principles of muscular activity:

• the increase in heart rate during muscular work is directly proportional to the intensity (power) of the performed activity;
• the degree of heart rate increase during a given physical workload is inversely proportional to an individual’s ability to perform muscular work of that intensity, which reflects their physical working capacity.

Therefore, heart rate response during muscular activity can be considered a reliable criterion for assessing the physical working capacity of Combat Horting athletes.

There are two main approaches to determining physical working capacity based on heart rate response to physical exercise:

1. assessment of heart rate during the performance of standardized muscular work;
2. determination of the workload intensity at which heart rate increases to a standardized level.

The second approach is considered more scientifically justified because it forms the basis of the PWC170 test methodology.

The selection of a heart rate level of 170 beats per minute is based on the fact that at this intensity the cardiovascular system continues to function within an optimal physiological range. In other words, at heart rates up to 170 beats per minute, there is a direct linear relationship between the power of muscular work and heart rate, while ATP (adenosine triphosphate) production occurs primarily through aerobic oxidation processes.

At higher heart rates, this linear relationship becomes disrupted due to increased activation of anaerobic (glycolytic) energy supply mechanisms during muscular activity.

Methods of Conducting the PWC170 Test

In sports practice, two main variations of the PWC170 test are commonly used:

• step test, in which physical workload is performed through repeated stepping onto a platform of a standardized height;
• cycle ergometry, in which workload is performed using a stationary bicycle ergometer.

Methodology for Determining PWC170 Using the Step Test

The height of the step most commonly used in the test is equal to approximately half of the length of the participant’s leg. Therefore, it is recommended to have a set of platforms with different heights (15, 30, 40 cm, etc.) to select an appropriate workload for each athlete.

The power of the performed physical work (W) can be determined using the following formula or by using standardized reference tables:

$$W \, (kgm/min) = 1.33 \times p \times h \times n$$

where:

• 1.33 — coefficient accounting for the amount of work performed during the downward movement from the step;
• p — body mass of the participant (kg);
• h — height of the step (m);
• n — number of step cycles per minute.

For example, assume that the participant’s body mass is 75 kg and the step height is 40 cm. The required stepping rate to achieve a workload of 1000 kgm/min can be calculated as follows:

$$1000 \, kgm/min = 1.33 \times 0.4 \times 75 \times X$$ $$X=\frac{1000}{1.33 \times 0.4 \times 75}=25 \text{ cycles/min}$$

Since one step cycle consists of four individual steps, 25 cycles correspond to a metronome tempo of 100 beats per minute.

The obtained value of physical working capacity of a Combat Horting athlete expressed in kgm/min can be converted into watts (W) by dividing the result by 6, because:

$$1W = 6 \, kgm/min$$

Procedure for Conducting the PWC170 Step Test

After selecting the optimal step height, the test is performed according to the following sequence:

1. Using Table 1, determine the individual number of step elevations according to the selected step height, the participant’s body mass, and the planned power of the first workload.

2. Apply electrocardiograph electrodes to record heart rate at the end of each workload stage (based on the R–R intervals of the electrocardiogram, ECG).

3. Perform the first workload (W₁) at a stepping rate of one cycle every two seconds for 5 minutes. Record the ECG during the final 30 seconds of the fifth minute to determine heart rate (f₁).

4. Rest in a sitting position for 3 minutes.

5. Perform the second workload (W₂) for 5 minutes. The number of step elevations and the step height are determined according to Table 2. The stepping tempo remains the same. ECG recording is performed using the same procedure as after the first workload.

6. Determine the PWC170 value using either a graphical or mathematical calculation method.

Table 1

Determination of the Performed Workload Power (kgm/min) During the Step Test Depending on the Body Mass of Combat Horting Athletes, Step Height, and Number of Step Cycles

(Number of step cycles per minute)

Body mass, kg

(The complete table should continue with 30 cm and 40 cm step heights in the same format.)

Graphical Method for Determining PWC170

The graphical determination of PWC170 is performed as follows: the power values of two consecutively performed workloads are plotted on the x-axis (abscissa), while the corresponding heart rate values are plotted on the y-axis (ordinate).

Two points are obtained based on the relationship between workload power and heart rate response. A straight line is drawn through these two points until it intersects the heart rate level of 170 beats per minute (bpm).

From the obtained intersection point, a perpendicular line is projected onto the x-axis. The resulting value represents the workload power corresponding to a heart rate of 170 bpm, which is defined as the athlete’s PWC170 value (Figure 1).

Figure 1. Graphical method for determining PWC170

where:

• HR₁ and HR₂ — heart rate values recorded after the first and second workloads;
• W₁ and W₂ — power values of the first and second workloads.

Methodology for Determining PWC170 Using a Cycle Ergometer

The participant is instructed to perform two consecutive workloads of moderate intensity (for example, 500 and 1000 kgm/min) with a pedal cadence of 60–80 revolutions per minute, separated by a three-minute rest interval.

Each workload lasts 5 minutes. At the end of each workload stage, heart rate (HR) is determined during the final 30 seconds using the auscultatory method (stethophonendoscope) or recorded by electrocardiography (ECG) for the same purpose.

The most rational approach for calculating PWC170 is not the graphical method but the mathematical method based on the substitution of heart rate and workload power values into the formula proposed by V. L. Karpman et al. (1974):

$$PWC_{170}=W_1+(W_2-W_1)\frac{170-f_1}{f_2-f_1}$$

where:

• PWC170 — physical working capacity corresponding to a heart rate of 170 beats per minute (kgm/min);
• W₁ — power output of the first workload (kgm/min);
• W₂ — power output of the second workload (kgm/min);
• f₁ — heart rate at the end of the first workload (beats/min);
• f₂ — heart rate at the end of the second workload (beats/min).

This equation allows the calculation of PWC170 when the power values of the first and second workloads and the corresponding heart rate responses are known.

Conditions for Reliable Determination of PWC170 in Combat Horting Athletes

The assessment of physical working capacity of Combat Horting athletes through PWC170 calculation provides reliable results only when certain methodological conditions are met.

When the difference between the first and second workloads is insufficient, the accuracy of PWC170 determination decreases. This occurs mainly because the cardiovascular regulatory system cannot accurately differentiate between workloads with very similar power values.

Therefore, during PWC170 testing, the power output of the second workload should differ substantially from the first workload. Recommended workload values that ensure reliable PWC170 determination are presented in Table 2.

Using these reference values, it is relatively easy to select appropriate workload intensities. The correctness of workload selection can be evaluated by the heart rate response at the end of each stage.

The expected physiological response should be:

• after the first workload: heart rate should reach approximately 100–120 beats/min;
• after the second workload: heart rate should reach approximately 160–170 beats/min.

The PWC170 test demonstrates sufficient methodological validity and reliability. An important advantage of the PWC170 procedure is that during testing it is possible to observe the participant’s subjective response and perception of the physical workload.

Table 2

Recommended Power Output of the First Workload (W₁, kgm/min) for Determining PWC170 in Combat Horting Athletes of Different Body Mass and Physical Ability Profiles

Among Combat Horting athletes, approximately 8.2% of individuals have a body mass below 55 kg, and nearly 91.0% of this group are female athletes.

Based on empirical data, recommendations have been developed for selecting the first workload power during cycle ergometer testing of Combat Horting athletes with body mass below 55 kg.

It is proposed to expand the lowest body mass category and begin classification from 50 kg. The recommended power output of the first workload should be established as follows:

• for speed-strength, complex coordination, game sports, and martial arts disciplines — 400 kgm/min;
• for endurance-oriented sports disciplines — 540 kgm/min.

Adjustment of PWC170 Testing Parameters in Combat Horting Athletes with Resting Bradycardia

It has been observed that among highly qualified Combat Horting athletes, 28.6% demonstrate resting heart rates within the range of 48–60 beats/min. Among these athletes, 65.6% are males and 34.4% are females.

During the submaximal PWC170 test, athletes with resting bradycardia demonstrate a heart rate response after the first cycle ergometer workload ranging from 85–90 beats/min to 100–120 beats/min. This physiological response may lead to an unjustified increase in the power of the second workload, resulting in a heart rate exceeding 170 beats/min at the end of the test and causing inaccuracies in the calculation of physical working capacity.

To prevent such errors, it is recommended to increase the power output of the first cycle ergometer workload:

• by 120–180 kgm/min when resting heart rate is within 55–60 beats/min;
• by 180–240 kgm/min when resting heart rate is within 48–54 beats/min.

The recommended values for calculating the second workload power required for reliable determination of PWC170 are presented in Table 3.

Table 3

Recommended Power Output of the Second Workload (W₂) for Determining PWC170

$$\mathrm{<strong>P</strong>}\mathrm{<strong>W</strong>}\mathrm{<strong>C</strong>}\mathrm{<strong>170</strong>}\mathrm{<strong>/</strong>}\mathrm{<strong>k</strong>}\mathrm{<strong>g</strong>}$$

Individual variations in PWC170 values are also influenced by sex, age, genetic factors, health status, and the level of physical activity.

In healthy young men who do not participate in sports (mean age 23.9 ± 6.1 years), the average PWC170 values are:

• 1001 ± 136 kgm/min;
• PWC170/kg — 14.4 ± 2.7 kgm/min/kg.

In women (mean age 24.1 ± 2.6 years), these values are:

• 640 ± 105 kgm/min;
• PWC170/kg — 10.2 ± 1.6 kgm/min/kg.

These data represent statistical indicators of physical working capacity among non-athletic individuals according to V. L. Karpman et al. (1988) and are presented as mean values (X ± δ).

This defense system includes:

• enzymatic antioxidants;
• non-enzymatic antioxidants;
• dietary antioxidants.

Examples include:

• glutathione (non-enzymatic antioxidant);
• superoxide dismutase (enzymatic antioxidant);
• vitamin E (dietary antioxidant).

The protective action of antioxidants occurs through neutralization of ROS molecules or elimination of intermediate products involved in ROS formation.

During Combat Horting training, when ROS levels increase significantly, there is a possibility that antioxidant defense mechanisms may become insufficient. This unstable physiological condition is known as exercise-induced oxidative stress.

The primary biological targets of oxidative stress include:

• proteins;
• lipids;
• DNA molecules.