PhD, Professor V.A. Vishnevsky¹
PhD, Associate Professor V.V. Apokin¹
PhD, Professor V.A. Grigoryev^1
1Surgut State University, Surgut

Keywords: cycle work test in closed power loop; work "to failure".

Background. The current study follows in the footsteps of the works on the predictive value of the main parameters of the hysteresis loop in the cycle work test in the closed power loop [1-3]. The subject of this research was to carry out a comparative analysis of the results of this test and work "to failure" performed with both the upper and lower limbs.

Objective of the study was to perform a comparative analysis of two cycle work tests in the closed power loop: involving the upper and lower limbs.

Methods and structure of the study. Sampled for the study were the 18±1.07 year-old students (n=36, including 21 young males and 15 females), who were subjected to four batteries of tests. The first battery included a closed power loop cycle work test performed on the TechnoGym cycle ergometer with the load increased and decreased in 15W steps, each step taking 1 minute. The initial work power was selected based on the body mass rate according to V.L. Karpman [4]. In the second battery, similar workload was performed with the upper limbs: 30W - for the young males, 15W - for the females. In the next two batteries of tests, 15W workload was performed "to failure", first - with the lower limbs, then - with the upper ones. The subjects' heart rate was recorded after each load step using the Polar cardio tester. The hysteresis loop generated by the test was analyzed by the author's software [1, 2]. We evaluated both the baseline parameters (pitch angle in the isoaccelerated loading phase α, pitch angle in the isoaccelerated unloading phase β, and square of the hysteresis loop S) and the estimates. Based on the circumferences and skin-fat folds of the thigh, shin, forearm, and shoulder, the skin-muscle girth of the corresponding segments was determined. The comparative analysis and determination of the predictive value of individual parameters of the hysteresis loop were based on the descriptive statistics, t-Student criterion, and correlation analysis.

Results and conclusion. The most common study results are presented in Table 1.

Table 1. Results of analysis of hysteresis loop in different test versions

* – differences are significant compared with the cycle work in the closed power loop performed with the lower limbs, p<0.05;

** – differences are significant compared with the leg work "to failure", p<0.05;

# – differences are significant compared with the group of young males.

The comparative analysis revealed that the key indicators of the hysteresis loop during the cycle work in the closed power loop were significantly higher when performed with the upper limbs than with the lower ones. Therefore, the current picture is in many respects similar to the previously observed one, when under the same workload, the response rates of the vegetative systems during the arm work are higher than during the leg wok [7], which is associated with the differences in the skeletal muscle mass rates [5, 6]. At the same time, when performing the workload with the upper limbs only, the females used most of their functional reserves and their α angle increased, while there was less intensive internal work (Ѕ) and faster recovery (β). All the baseline values of the hysteresis loop were greatly associated with the pulse debt. Angle α: in the lower-limb cycle work test - young males r=0.683, p<0.01, young females r=0.747, p<0.01; in the upper-limb cycle work test - young males r=0.501, p<0.05, young females r=0.822, p<0.01. Angle β: in the lower-limb cycle work test - young males r=-0.478, p<0.05, young females r=-0.505, p<0.05; in the upper-limb cycle work test - young males r=-0.656, p<0.01, young females r=-0.514, p<0.05. Square of the hysteresis loop S: in the lower-limb cycle work test - young males r=0.755, p<0.01, young females r=0.713, p<0.01; in the upper-limb cycle work test - young males r=0.525, p<0.05, young females r=0.735, p<0.01. At the same time, the greatest differences in the pulse rate in the young males and females were observed during the upper-limb cycle work: during the leg work - young males - 0.189±0.072 beats/W, young females - 0.265±0.100 beats/W; during the arm work - young males - 0.431±0.124 beats/W, young females - 0.822±0.333 beats/W. The relationships between the parameters of the hysteresis loop when working with the upper and lower limbs, although statistically significant, were weak.

The key parameters of work "to failure" are presented in Table 2. The upper-limb cycle work was characterized by the lower power and failure pulse rates, but a greater pulse cost. The females were found to have a lower failure rate, "failure" HR similar to that in the males, and a higher pulse cost of workload. The failure rate per unit of the musculoskeletal girth (MSG) was generally higher for the upper limbs. At the same time, when working with the lower limbs, the performance rates in the females differed statistically significantly from those in the males.

Table 2. Key parameters of work "to failure"

* – differences are significant compared with the leg work "to failure", p<0.05;

** – differences are significant compared with the group of young males.

The pitch angles in the loading phase α when working "to failure" with the upper and lower limbs did not differ significantly from the corresponding indicators of the cycle work in the closed power loop (Table 1). At the same time, the α angle during the lower-limb cycle work in the closed power loop had a negative correlation with the failure rate (r=-0,438, p<0,01) and a positive one - with the average pulse cost of work "to failure" (r=0.461, p<0,01). It was positively correlated with the pitch angle in the loading phase (r=0.412, p<0.05), pulse cost of the arm work "to failure" (r=0.455, p<0.01) and negatively correlated with the failure rate (r=-0.482, p<0.01) and power per unit of the musculoskeletal girth of the forearms (r=-0.385, p<0.05). The α angle during the upper-limb cycle work in the closed power loop had numerous correlations with the parameters of the arm work "to failure": angle α (r=0.636, p<0.01); failure rate (r=0.602, p<0.01); pulse cost (r=0.582, p<0.01); MSG of the forearms (r=-0.472, p<0.01) and shoulders (r=-0.498, p<0.01). Similar correlations could be traced for the failure rate (r=-0.525, p<0.01) and pulse cost (r=0.502, p<0.01) of the leg work "to failure".

The pitch angle in the unloading phase β in the lower-limb cycle work test was characterized by the weak correlation with power (r=0.335, p<0.05), pulse cost (r=0.435, p<0.01), musculoskeletal girth of the thigh (r=-0.427, p<0.01) and shin (r=-0.403, p<0.05) when working "to failure". The correlations with the parameters of the arm work "to failure" were stronger: with the power per unit of the musculoskeletal girth of the upper limbs - r=0.633, p<0.01; with the pulse rate per unit of the musculoskeletal girth of the upper limbs - r=0.575, p<0.01. During the arm work, this angle was weakly correlated with the failure rate (r=0.361, p<0.05) and pulse cost (r=-0.341, p<0.05) of the leg work "to failure" and a number of indicators of the arm work "to failure": angle α (r=0.346, p<0.05); power per unit of the musculoskeletal girth of the forearms - r=0.356, p<0.05; pulse per the musculoskeletal girth of the arms - r=0.400, p<0.05.

The square of the hysteresis loop S during the leg work is associated with the failure rate per unit of the body mass (r=-0.459, p<0.01) and unit of the musculoskeletal girth of the lower limbs (r=-0.362, p<0.05) when working "to failure" using the lower limbs, as well as with the failure rate (r=-0.335, p<0.05), power (r=0.647, p<0.01) and pulse rate (r=0.678, p<0.01) per unit of the musculoskeletal girth of the upper limbs. The square of the hysteresis loop S during the arm work correlates with power (r=0.653, p<0.01) and pulse cost (r=0.614, p<0.01) per unit of the musculoskeletal girth of the upper limbs.

The power (N_failure/MSG) and performance efficiency (HR_failure/N_failure/MSG) rates of MSG of the upper and lower limbs were of particular interest. In terms of the leg work, the young males demonstrated greater power per unit of the thigh (r=0.513, p<0.01) and shin (r=0.449, p<0.01) muscle tissue and a smaller pulse cost (r=-0.555, p<0.01). The power per unit of the musculoskeletal girth of the thigh (r=-0.877, p<0.01) and shin (r=-0.803, p<0.01) had a negative correlation with the performance efficiency of the musculoskeletal girth of the legs as a whole. There was no such dependence in relation to the arm muscles. The power per unit of the thigh muscle tissue was negatively correlated with the average pulse cost for the angles α (r=-0.511, p<0.01) and β (r=-0.521, p<0.01) during the upper-limb cycle work in the closed power loop. For the shin, this correlation was r=-0.509, p<0.01 and r=-0,516, p<0,01, respectively. Similarly, the pulse cost of the arm work "to failure" for the α angle correlated with the power of the musculoskeletal girth of the thigh (r=-0.560, p<0.01) and shin (r=-0.492, p<0.01).

Conclusion. The findings enhance our insight into the predictive value of the hysteresis loop parameters during the upper- and lower-limb cycle work in the closed power loop as compared to the work "to failure". The probes complement each other. This enables to run a cycle work test in the closed power loop in individual cases as an alternative to workload "to refuse", which involves certain complications and risks.

References

1. Vishnevskiy V.A. Cyclic workout test with closed power loop: performance forecast application.  Teoriya i praktika fiz. Kultury, 2017. No. 11. pp. 83-85.
2. Vishnevskiy V.A. Cyclic workout test with closed power loop: performance forecast application. Teoriya i praktika fiz. kultury. 2019. No. 9. pp. 90-92.
3. Davidenko D.N., Rudenko G.V., Chistyakov V.A. Methods for assessing mobilization of body functional reserves by its response to graded load. Uchebnye zapiski universiteta im. P.F. Lesgafta. 2010. no. 12 (70). pp.  52-57..
4. Karpman V.L., Belotserkovskiy Z.B., Gudkov I.A. Testing in sports medicine. Moscow: Fizkultura i sport publ., 1988. pp. 21-46.

Corresponding author: apokin_vv@mail.ru

Abstract

Objective of the study was to perform a comparative analysis of two cycle work tests in the closed power loop: involving the upper and lower limbs.

Methods and structure of the study. Sampled for the study were the 18±1.07 year-old students (n=36, including 21 young males and 15 young females), who were subjected to four batteries of tests. The first battery included a closed power loop cycle work test performed on the TechnoGym cycle ergometer with the load increased and decreased in 15W steps, each step taking 1 minute. In the second battery, similar workload was performed with the upper limbs: 30W - for the young males, 15W - for the young females. In the next two batteries of tests, 15W workload was performed "to failure", first - with the lower limbs, then - with the upper ones. The subjects' heart rate was recorded after each load step using the Polar cardio tester. The hysteresis loop generated by the test was analyzed by the author's software.

Results and conclusions. The key indicators of the hysteresis loop in the upper-limb cycle work in the closed power loop were significantly higher than those in the lower-limb one. At the same time, when performing the workload with the upper limbs only, the females used most of their functional reserves and their α angle increased. Yet, there was less intensive internal work (Ѕ) and faster recovery (β). All the baseline values of the hysteresis loop are greatly associated with the pulse debt. The upper-limb cycle work was characterized by the lower power and failure pulse rates, but a greater pulse cost. The females were found to have a lower failure rate, "failure" HR similar to that in the males, and a higher pulse cost. The failure rate per unit of the musculoskeletal girth is generally higher for the upper limbs. At the same time, when working with the lower limbs, the females were inferior to the males in terms of this indicator and almost caught up with them when performing the test with their upper limbs. The greatest number of correlations between the hysteresis loop parameters was associated with such indicators of the probe "to failure" as failure rate, pulse cost, and failure rate per unit of the musculoskeletal girth of the upper and lower limbs.