Study On Secular Trends And Correlation Analysis Of Forced Vital Capacity And Physical Qualities Among The Han Students In Ningxia From 2000 To 2014

Objective To understand the trend of forced vital capacity and physical qualities of Han students in Ningxia aged 7-18 years from 2000 to 2014 and analyze the correlation between the vital capacity and physical qualities so as to provide the scientific evidence on improving the physical qualities of the Han students in Ningxia students.Methods The Han students in Ningxia from 2000 to 2014 aged 7-18 years were selected as the study subjects in the database of Chinese National Survey on Students Constitution and Health,with the sample size of 28749,included 14431 boys and 14318 girls.The subjects were divide into different economic areas according to the the economic areas determined in 1985.To analyze the forced vital capacity and physical qualities of Han students in Ningxia from 2000 to 2014 aged 7-18 years and the correlation between the vital capacity and physical qualities.Results 1.The vital capacity of boys and girls in Ningxia aged 7-18 years had the decreased trend from 2000 to 2010 and increased from 2010 to 2014(P<0.001).The increment of vital capacity was 310.09 ml in boys and 176.30 ml in girls from 2010 to 2014.The level of vital capacity in boys was higher than in girls in each year(P<0.001).The trend of vital capacity in students in each economic areas was consistent with the overall Han students in Ningxia.2.The speed quality of boys and girls in Ningxia aged 7-18 years from 2000 to 2014 had the decreased trend(P<0.001).The increment of the time of 50-meter race was 0.04 s in boys and 0.14 s in girls.The time of 50-meter race in girls was higher than in boys in each year(P<0.001).The speed quality of boys and girls in the good economic areas has beenimproved.The speed quality of boys in the middle economic areas has been improved,but the speed quality of the girls has decreased.The speed quality of boys and girls in the poor economic areas continued to decline.3.The lower limb explosive power of Han students in Ningxia aged 7-18 years had declined from 2000 to 2014(P<0.001).The decrement of standing long jump was 10.11 cm in boys and 9.50 cm in girls.The level of standing long jump in boys was higher than in girls in each year(P<0.001).The trend of lower limb explosive power of boys and girls in each economic areas is consistent with the overall Han students in Ningxia.4.The physical endurance of Han students in Ningxia aged 7-18 years had the decreased trend from 2000 to 2014(P<0.001).The increment of the time of 50mx8 shuttle race was7.61 s in boys and 6.54 s in girls aged 7-12.The time of 50mx8 shuttle race in girls was higher than in boys in each year(P<0.001).The time of 1000-meter race had the increased trend(P<0.001),the increment of was 17.56 s in boys aged 13-18.The time of 800-meter race had the increased trend(P<0.001),the increment of was 11.57 s in girls aged 13-18.The physical endurance of boys aged 7-12 years in the good economic areas has been improved from 2010 to 2014.5.The flexibility of Han students in Ningxia aged 7-18 years had the increased trend from 2000 to 2005 and decreased from 2005 to 2014(P<0.001).The descended extent to sit-and-reach in boys was 2.37 cm,the average decline rate was 32.03% from 2000 to 2014.The descended extent to sit-and-reach in girls was 0.39 cm,the average decline rate was4.86% from 2000 to 2014.In addition to the growth trend of the flexibility of girls in the middle economic areas,the flexibility level of the boys and girls in the other economic areas declined from 2000 to 2014.6.There is a positive relationship between the vital capacity and the most physical qualities indexes。There is a negative correlation between the vital capacity and the time of50-meter race and endurance running,and a positive correlation with the score of thestanding long jump.Conclusion 1.The vital capacity of boys and girls in Ningxia aged 7-18 years had the decreased trend from 2000 to 2010 and increased from 2010 to 2014.However,the level of vital capacity of boys and girls in Ningxia was slightly higher in 2014 compared with 2010.2.The speed quality of boys and girls in Ningxia aged 7-18 years from 2000 to 2014 had the decreased trend.The speed quality of boys and girls in the good economic areas has been improved.The lower limb explosive power of Han students in Ningxia aged 7-18 years had declined from 2000 to 2014.The physical endurance of Han students in Ningxia aged7-18 years had the decreased trend from 2000 to 2014.Only he physical endurance of boys aged 7-12 years in the good economic areas has been improved from 2010 to 2014.The flexibility of Han students in Ningxia aged 7-18 years had the increased trend from 2000 to2005 and decreased from 2005 to 2014.The flexibility of girls aged 13-18 years in the middle economic areas had the decreased trend.3.There is a positive relationship between the vital capacity and the most physical qualities indexes。There is a negative correlation between the vital capacity and the time of50-meter race and endurance running,and a positive correlation with the score of the standing long jump.