The Blood Pressure And Heart Rate Response To Medium-speed Walking And Influence Factors In The Youth Students

Objective: To explore the responses of blood pressure(BP) and heart rate (HR) for youth students in their moderate-speed walking and the factors related to them.`Method: Subjects consist of 70 youth students (aged at 21.0+2.0) and they are required to walk 900 meters within 9 minutes in the open air with the temperature of 8-10℃. Their orthostatic BP and HR were taken twice with electronic sphygmomanometer after 10-minute rest and the means of the results of BP and HR serve as before-motion BP and HR. During their 9-minute walking, the BP and HR were taken every 3 minutes, that is, three times altogether. The subjects were required to have a rest with seating themselves, and just after their sitting down to rest their BP and HR were taken. The value got in this period is named"value of the 1st minute". After that, the BP and HR are taken every 3 minutes and are ended at the 16th minute. And the measure results of BP and HR were recorded respectively as"4 minutes","7 minutes","10 minutes","13 minutes"and"16 minutes". For those who don't recover after 16-minute rest, the results were recorded as 16 minutes.At the same time, the subjects'age, gender, hypertension family history, height, weight, conditions of physical training and smoking and some other factors were recorded. Motion quantization: 4 to 7 times exercises with each time lasting more than 30 minutes per week are considered as regular exercises and 0-3 times exercises per week are considered as seldom regular exercises. The subjects are divided into smoking group and non-smoking group. The former was made up of the students having smoking or passive smoking experiences in the past half year. The rest of them having not any smoking experiences serves as non-smoking group. The subjects whose parents, or one of their parents, have hypertension are known as the ones having hypertension family history.Index of motion period: BP-AI and HR-AI: the difference between the BP maximum in walking process and BP value of before-motion. AUC of motion BP and HR response: the starting point represents before-motion and the terminal point represents 9-minute motion, and then the AUC of SBP, DBP and HR are figured out respectively. The AUC of BP and HR of while-walking period and recovery period are figured out respectively.Index of recovery period: BP-RT and HR-RT: refers to the time used to recover to 95% level for motion amplification. AUC of BP and HR in recovery time: the starting point represents the 1-munite rest after the motion and the terminal point represents the results measured after 16-minute rest. AUC of BP and HR in RT are figured out.Results:Exercise period1. The SBP increased about 12.4mmHg, DBP increased 10.0mmHg and heart rate increased 10.8 bpm in motion. The most significant difference happened at the 9th minute.2. There was no statistical significance in the difference of SBP-AUC between regular exercises group and seldom exercises group. But the changes trends of DBP were completely different in two groups: for regular exercises group, DBP increased a bit after decreasing; for seldom exercises group, DBP increased throughout the process. The value of motion period's DBP-AI and DBP-AUC for seldom regular group are significantly larger than regular exercises group. For subjects in regular exercises group, their basic HR are obviously lower when they are in motion phase, their HR increased at the beginning and then stay at the same level. For seldom regular exercises group, their HR increased increasingly. But there weren't significant differences between the two groups'HR-AUC.3. Compared with matched non-hypertensive family history group, the growth rates of motion SBP and SBP-AUC of the seven subjects having the hypertensive family history are significantly higher. Although the DBP-AUC and HR-AUC are higher, they are not statistically significant.4. The value of the HR in different time in the process of motion is significantly different. (P<0.05). The influence to the changes of HR in the process of motion caused by different genders and different exercise habits are significantly different. (P<0.05) and also the influence caused by different genders and different exercise habits can interact in different time. (P<0.05)Recovery period:Most subjects'BP and HR completely recover to normal state with one-minute rest. The influence of different genders to the changes of HR in the process of recovery time is significantly different. (P<0.05). The parameters for hypertensive family history group and non-hypertensive family history group, regular exercises group and seldom regular exercises group and male group and female group are not significantly different.Conclusions: Moderate speed walking can cause the significant increase of the youth students'BP and HR. Hypertensive family history and a lack of exercise are motivators of the increase of exercises BP.