MODIFICATION OF HARVARD STEP-TEST FOR ASSESSMENT OF STUDENTS’ WITH HEALTH PROBLEMS FUNCTIONAL POTENTIALS

Purpose: to substantiate, work out and experimentally prove modified test for assessment of students’ with health problems functional potentials. Material: in the research students and girl students of 18-20 years’ age (n=522) participated. According to the worked out modification of test during 30 seconds student ascended on bench (h=43 cm) and descended from it. Then pulse was measured three times. In total the test took 4 minutes. Results: For working out the scale for interpretation of the received results we assessed new 30 seconds’ modification of Harvard step-test for validity. First, for this purpose all students fulfilled modified step-test. Then after full restoration (after 20 minutes) they fulfilled its three minutes’ variant. Correlation analysis of the received results showed the presence of average correlation between two samples (r=0.64). Conclusions: application of this modified variant permits for pedagogues to completely assess functional potentials of students with heath problems.

The purpose of the work: is to substantiate, work out and experimentally prove modified test for assessment of students' with health problems functional potentials.

Material and methods
Participants: in the research students of main group (without health problems) participated: girls and boys of 18-20 years' age (n= 522).All participants were familiarized with "Helsinki declaration of world health protection association" [23] and gave written consent for participation in experiments.
Organization of the research: Harvard step test is used for the following: assessment of physical potentials before sports trainings; working out of training programs; assessment of sport training programs' effectiveness; assessment of person's physical fitness by his (her) cardio-vascular system's reaction to physical load.
At present some interpretations of Harvard step test are known.All hey imply load (ascending on bench h=43 cm) during 3 or 5 minutes.However, this load is excessive for most of persons with health problems.That is why teachers of physical education department of National Research University Belgorod State University worked out modified 30 seconds variant of Harvard step-test especially for students with health problems [16].
According to new modification of Harvard step-test student ascended on bench (h=43 cm) and descended from it during 30 seconds with speed 30 steps per minute.In ascending and descending arms moved naturally like in ordinary walk.For exact dozing of frequency of ascends and descends we used metronome.Frequency of metronome was adjusted for 120 beats per minute (every movement corresponded to one metronome beat).After fulfillment of step-test student had rest in sitting position.The his pulse was measured three times (1.5 minutes since beginning of the test) during 30 seconds (Р1), after 2 minutes of rest (2.5 minutes since beginning of the test) during 30 secondsв (Р2), after 3 minutes of rest (3 minutes since beginning of the test) during 30 seconds (Р3).In total test took 4 minutes.
Coefficient was calculated by the following formula: For working out interpretation scale of the received results we assessed for validity new 30 seconds' modification of Harvard step-test.For this purpose 522 absolutely healthy students fulfilled first modified steptest.Then, after complete restoration (in 20 minutes) they fulfilled 3-minutes' variant of test.
Statistical analysis: we conducted correlation analysis of the received results.The analysis showed the presence of average correlations between two samples (r=0.64).Program SPSS 22 was used.

Results of the research
For working out interpretation scale of the received results of 30 seconds' Harvard step-test modification for students with weakened health we carried out correlation analysis of the received data.The data were analyzed for the presence of statistical correlation in the given sample.In fig. 1 the received results are presented visually.
Analysis of the obtained data permits to notice regularity in distribution of heart beats rate values in both variants of Harvard step-test.
Besides, we formed correlation field (see fig. 2).Analysis of this field permitted to find perfect correlation of the studied data.We determined that higher values of one property are corresponded to by higher values of other property.In the same way lower values of one property are corresponded to by lower values of other.Thus we can say about average correlation between two samples (r=0.64).
The received data permitted to work out the following interpretation scale of Harvard step-test 30 seconds' modification results for persons with weakened health: "Excellent" -26 conv.un. and more; "Average" -20-22 conv.un.; "Weak" -17-19 conv.un.; "Bad" -16 conv.un. and less.And finally, it should be noted that the conducted research of students' functional potentials permitted to prove reliability of the worked out modification of 30 seconds' Harvard step-test.The accumulated up to present time experimental material on this problem witnesses that with the help of 30 seconds' modification of Harvard step-test specialists can completely assess functional potentials of students with health problems.

Discussion
The carried out monitoring of students' health showed tendency to its worsening during studying at HEE. Specialists in physical culture and sports point at existence of substantial restrictions in physical exercises' fulfillment by students with different health problems [27].However, there is a demand in reliable functional and control tests, which could be applied for assessment of functional potentials of students with health problems.Results of prof.Zaporozhanov's works prove correctness of such approach.The author showed purposefulness of perfection of dexterity control for substantiation of kinesthesia quantitative and qualitative assessment in specific conditions of physical education [31].Besides, the need in the following is noted:  To base on objective, metric information, received in researches with wide contingent of participants, who demonstrate good concentration of attention and high reliability of results in series of repeated measurements [33];  Substantiation of more reliable informative indicators and purposefulness of their calculation for control over sportsmen's complex fitness [34];  Purposefulness of usage of only previously substantiated and reliable results in statistical operations [32].
The conducted by us analysis of scientific works did not show suitable functional tests, which could permit to assess functional potentials of students with health problems.The existing modifications of Harvard steptest are suitable for healthy people of different age and sex [22, 24, and 27].Application of the worked out by us modified 30 seconds' Harvard step-test permits for specialists to completely assess functional potentials of students, for whom earlier usage of tests had counter-indications because of these students' health.Study of functional potentials of students with health problems permitted for us to prove the reliability of the worked out 30 seconds' Harvard step-test.Our research permits to assume that for other age groups with health problems the worked out by us step-test modification can also be applied.

Conclusions
The worked out by us modified 30 seconds' variant of Harvard step-test is now being widely used by physical education departments of Russian HEEs.Usage of adapted variants of this test permits for pedagogues to completely assess functional potentials of students with different health problems.