中老年人在FATmax强度下运动时心血管风险指标的变化

Effects of FATmax Intensity Exercise on the Cardiovascular Indexes in the Elderly

目的探讨55～65岁中老年人在最大脂代谢强度下（FATmax）运动时，不同时间点上心血管风险指标的变化，为中老年人制定有效、安全的减脂运动处方提供一定的理论指导。方法招募55—65岁中老年人50名，通过递增运动负荷试验（GXT试验）测试出每位受试者FATmax时的心率。间隔3天以上，使每位受试者心率控制在FAT—max对应的靶心率范围内持续运动30～60min。每5min测量一次血压，心率通过运动心电图实时监测。研究分析运动第15、30、45和60min等不同时间点上心血管风险指标的变化。结果（1）在FATmax强度下持续运动到30min时间点上的41名受试者，超重组的收缩压变异系数与正常体重组相比，有显著性差异（P〈0．05）；持续运动15、30min时间点上，女性SBP、脉压上升水平均低于男性，在30min时间点上两者有显著性差异（P〈0．05）。（2）在FATmax强度下持续运动60min的21名受试者中，14名男性在运动45、60min时间点上DBP基本保持不变，SBP、脉压、RPP均比安静状态显著升高（P〈0．01），2个时间点之间相比并无显著性差异。7名女性在运动45min和60min时间点上比较，SBP、脉压、RPP有显著性降低（P〈0．05），收缩压标准差有显著性升高（P〈0．05）；运动45min时女性与男性相比，舒张压有显著性下降（P〈0．05）。（3）运动60min时间点上，男、女性SBP反应异常率分别达到21．43％和71．43％。结论55—65岁中老年人在FATmax下持续运动30min是安全的，持续运动60min时女性发生心血管风险的可能性高于男性。

Objective To discuss the cardiovascular reactions and changes at the different moments during the course of FATmax intensity exercise in 55 - 65 years old people, and to evaluate the cardiovascular risk factors for the better exercise prescription designs. Methods 50 people of 55 -65 years old were recruited and took part in the study after the regular physical examination, and everyone gave his or her formal consent. FATmax heart rate were monitored during the graded intensity exercise tests（ GXT test）. 3 days later, every subject kept on exercise for 30 - 60 minutes at the individual target hearts of FATmax monitoring by the exercise ECG, and the blood pressure were examined every 5 minutes. The changes of cardiovascular risk indexes were observed and analysised at the different moments： 15 min,30 rain,45 rain and 60 nlin mo- ments of the exercise duration. Results （ 1 ） Among the 41 subjects who kept on exercise for 30 minutes, as to the coefficient of variation of the systolic blood pressure（SBP） , there were significant difference between the normal weight subjects group and the over- weight subjects group（ P 〈 0. 05 ） ;compared the 15 minute exercise moment and the 30 minute ones, the SBP and pulse pressure of females subjects group increased lower than those of males, and the two indexes of the 30 minute moment displayed differently（P 〈 0. 05 ）. （2）21 subjects completed the 60 minutes exercise at the FATmax intensity,The dias- tolic blood pressure（DBP） of the 45 min, 60 rain in the 14 male subjects almost remained the normal status,while the SBP,pulse pressure and RPP increased significantly comparing with the resting conditions （ P 〈 O. O1 ）, and no difference were found between the two moments. Compared the same two moments in the 7 female subjects, SBP, pulse pressure and RPP de- creased（P 〈 0. 05）, and the standard of SBP elevated significantly（P 〈 0. 05 ）. The DBP of female subjects were lower than that of the male ones at the 45 min moment of the exercise duration（ P 〈 0. 05 ）. （ 3 ） The abnormal rate of SBP reaction at the 60 rain moment of the exercise duration were 21.43% and 71.43% respectively. Conclusion It is safe for the 55 - 65 - year old people to keep on 30 minutes exercise at FATmax intensity, and the risk of the cardiovascular for the females is higher than the males ones when this exercise duration approaching 60 minutes.