Introduction
Preschool Years are important stages for growth and health development. Young children are the hope of future society. Good physiological and psychological development for young children are considered as important keys to improving social economy. Therefore, studying the physical fitness of children has an important contribution for society.

So far, there is not any study report or analysis of physical fitness status and the changing regularity of young children in Macao. In order to know the physical fitness status of Macao children, Macao Sport Development Board and National Research Institute of Sports and Science undertook the research on physical fitness of 3 to 6 years old children in Macao in 2002. Testing work, supported by Health Bureau, Education and Youth Affairs Bureau, Social Welfare Institute and Macao Polytechnic Institute, has been completed in December 2002. After finishing this research, we have got the basic physical fitness data of Macao children. At the same time, we can develop further research on the basis of testing results and to provide scientific references for parents and teachers to help children improving their health.

Objectives and Methods
Objectives
To comprehensively obtain the physical fitness status of 3 to 6 years old children in Macao, establish database about physical fitness and lay the foundation for dynamic monitor in the future. On the other hand, to develop further research and conduct comparative analysis of physical fitness among different regions on the basis of testing results. These can provide scientific references for decision-making of relatively functional departments, thereby promoting physical fitness and health of children more effectively.

Method for sampling
From 3 to 6 years old children at schools and nurseries in Macao, 60 boys and girls respectively from each half year age group were selected at random. After checking, 902 samples were chosen to form a valid amount of sample. See Table 1 for the sample distribution in detail.

Table 1 Sample Distribution in Each Age Group

Method for research

Testing methods
The test was undertaken according to the requirement of "2000 National Physical Fitness Surveillance Manual". The test items were as follows,
Physique: height, weight, sitting height, chest circumference, upper arm skinfold thickness, subscapular skinfold thickness, and abdomen skinfold thickness.
Physiological function: resting pulse rate.
Physical fitness: standing long jump, throwing distant tennis ball, 10m shuttle run, walking on balance beam, success ional jump with both feet.
Health care index: decayed tooth.

Questionnaire methods
At the same time of physical fitness test, we did the questionnaire survey. Questionnaire items contained personal information of the child such as birth height and weight, feeding patterns within four months after birth, disease history, sleep time, participating condition about sports and literature activity, parents' information such as height, weight, participating condition about sports, occupation and education condition.

Method of statistics

SPSS statistics software mix is applied to conduct statistical operation on data.

Results

The testing results of physique
The study shows that the height and weight of both boys and girls in Macao increases along with their age. Boys are a little taller than girls. From 3 years to 6 years, the height changing confine of boys are 97~117.7cm, height averagely increases 6.4cm each year, the total increase of height is averagely 20.7cm. For girls, the height changing confine are 95.3~116.5cm, height averagely increases 6.1cm, the total increase of height is averagely 21.2cm.

The average weight of boys are from 14.4kg of 3 years' to 21.7kg of 6 years'. For girls, from 14.1kg to 20.3kg. Boys and girls' weight increases 2.3kg and 1.9kg respectively each year averagely. The total increase is 7.3kg for boys and 6.2kg for girls.

Table2  Mean and SD of height and weight of children in Macao

** Boys VS girls P<0.01

The horizontal development of physique, both Macao boys and girls¡¦ chest circumference increases along with their age. For boys, the average chest circumference are from 51.3cm of 3 years' to 57.8cm of 6 years', the total increase is 6.5cm. For girls, from 50.6cm to 55.7cm, the total increase is 5.1cm. Boys' chest circumference increase speed is faster than that of girls. The skinfold thickness also increases with age, the average level of skinfold thickness at the upper arm is the highest, followed by abdomen and shoulder blade in both boys and girls. The total skinfold thickness level of girls is larger than that of boys of the same age.

Table 3 Mean and SD of chest circumference, skinfold thickness of children in Maca

* Boys VS girls P<0.05 , ** Boys VS girls P<0.01

Results show that the average level of height, weight, chest circumference and  skinfold thickness of the children increases along with their growth in age. The increasing speed of height is faster than that of weight and chest circumference. This makes 3-6years old children taller and thinner with their growth in age. There is no great difference for sexes in height and weight. Chest circumference of boys are larger than those of girls, while skinfold thicknesses at three parts of girls are greater than boys.

Specially, weight for height can be used to compare with the weight level for the same height. It is universally recognized as an ideal index to evaluate weight level and nutritious status. According to weight for height standard for 3-6 years old children based on 2000 National Physical Fitness Surveillance Data, the weight of children are categorized into 5 levels as malnutrition, low-weight, normal-weight, overweight and obesity. As a result, we find that the percentage of normal-weight is 71.3% in Macao boys and 65.4% in girls. For boys, the percentage of malnutrition and low-weight are 3.3% and 10.2%, for girls, 9.9%and 16.1%. There are 9.8%(boys), 2.8%(girls) in the status of obesity. It shows that the problems of boys in Macao are malnutrition and obesity, while girls¡¦ malnutrition is of concern.

Table 4 Nutrition status of children in Macao

 
The testing results of physiological function
Heart rate is an indication of cardio-capacity and physical fitness. The results show that the heart rate of children in Macao decreases when they grow older. However, there is no significant difference between sexes at each age group.

Table 5 Mean and SD of heart rate of children in Macao

The testing results of physical fitness

The testing items for physical fitness are standing long jump, throwing distant tennis ball, sit and reach, l0 m shuttle run, walking on balance beam, success ional jump with both feet. We use these items to measure burst-out strength of lower limbs, the strength of upper limbs, waist and abdomen, the flexibility of muscle and ligament, speed and agility, balance ability, body coordination of the children respectively.

Table 6  Mean and SD of physical fitness indices of children in Macao

* Boys VS girls P<0.05 , ** Boys VS girls P<0.01

Results show that the achievements of all the physical fitness indices except sit and reach are improved with their growth in age. This proves that children aged 3 to 6 have significant improvement in strength, coordination, speed, agility and balance. The decrease of body flexibility with growth in age is normal situation. Although strength, speed and agility of boys are better than those of girls, especially in the 4.5 age group, their flexibility is apparently weak. As to balance ability, before 4.5 years old, girls have better balance ability than boys. However, after the age of 4.5, girls' balance ability tends to drop behind boys.

Analysis of general fitness level of 3-6 years old children in Macao

According to the general fitness level standard based on 2000 National Physical Fitness Surveillance data, we assessed the general fitness level of Macao children with the total scores of all the testing items which the children got. It is found that 81.3% children reach 'average' category or above, the percentage of 'excellent' category is 9.1% and 'good' category is 17%. But the percentage of 'poor' category in Macao is the highest (18.7%) in comparison with mainland China. The score of each fitness testing item the children got is also lower in Macao. The general physical fitness level of Macao children is apparently lower.

                          Figure 1 General Fitness Level in Four Regions

Dental caries in Macao children aged 3 to 6
Dental caries is the most common disease in children. Results of this survey show the rate of dental caries of 3 to 6 years old children in Macao increases with their growth in age. After 5.5 years old, the rate of decayed reaches 53.9%, but the rate of filled milk tooth is less than 10%. The rate of tooth falling caused by serious erosion keeps increasing from 3 to 6 years old. Health department should strengthen oral hygiene practices for early children as soon as possible and promote parental awareness on how to protect their children¡¦s dental health.

Table 7 The Prevalence of Dental Caries of 3 to 6 Years Old Children in Macao

Discussion
Results of this survey show that the physique and physiological function development of children in Macao are in normal range. But the general fitness level is not so good. In general, there are some problems as follows,

   1. For boys, the percentage of low-weight and obesity are higher. This shows that the problems of boys in Macao are malnutrition and obesity, while girls' malnutrition is of concern. This points out that parents should pay attention to the nutrition problem of their children and prevent their children to get a bad diet habit.
   2. From 3 to 6 years, the strength, speed, agility and flexibility development of the boys and girls in Macao are relative slow. The general fitness level of children in Macao is not so good. The results point out that a further study in promoting physical activities level of children in Macao is necessary. It is important for parents to be aware of participating in physical activities, the teachers to plan and set more high quality physical courses at kindergartens and schools.
   3. Dental caries of 3 to 6 years old children in Macao increases with their growth in age. Health department should strengthen oral hygiene practices for early children¡¦s health growth.

In order to enhance the general fitness level of Macao children, we suggest that more outdoor physical activities are necessary for children in Macao. It is important for kindergardens and schools to promote exercises and let parents get more knowledge about taking care of children in scientific ways.

References

   1. Science and Education Dept. of China State Sport General Administration. Research of Physical Fitness Surveillance System of China. Beijing University of physical education's Publishing House. 2000:First edition
   2. Study Team on Physical Fitness and Health of Chinese School Students. Report on the Physical Fitness and Health Surveillance of Chinese School Students. Higher Education's Publishing House,2002
   3. Chen Ming-Da et al. Practical Study of Physical Fitness. Beijing Medical University /Peking Union Medical College's Publishing House.1993: First edition
   4. Science and Education Dept. of China State Sport General Administration. Research of Physical Fitness Status of 3-6 Year Old Children in 1998. Beijing Medicine College's Publishing House.2002: First edition
   5. Mass Sport Dept. of China State Sport General Administration. Report on Physical Fitness Surveillance of Chinese People in 2000.Beijing University of physical education's Publishing House.2002:First edition
   6. Ma You-Sheng et al. The Relationship Between Decayed Milk Tooth and Growth of 3 Year Old Children. China Stomatology Periodical. 1998. 23(1):97