Predictors of fatness and physical fitness in nine-year-old Icelandic school children

Abstract

This study was conducted to elucidate the characteristics of children who were born later in the school year, exhibiting better physical fitness. The subjects were 1202 public elementary school children（grades 1-6）in Ibaraki prefecture, for whom birth date, height, weight, physical fitness test scores, and physical activity had been assessed by questionnaire. They were divided into four categories by birth date：Q1, April-June；Q2, July-September；Q3, October-December；and Q4, January-March（including April first). All data were integrated after classification by grade and gender. Physical fitness groups were defined to include subjects who had more than 50 physical fitness deviation score as a higher physical fitness group（HPF). The others were a lower physical fitness group（LPF). Results of statistical analysis show for Q4 that physical activity of HPF had a higher value than LPF, although no difference was found for height or BMI. For HPF, a lower value was found for height of Q4 than for either Q1 or Q2, although no difference was found for BMI or physical activity. These results demonstrate that although elementary school children who were born later in the school year and who had higher physical fitness showed poor body size, they attained higher physical fitness through higher levels of physical activity. Key words：relative age effect, elementary school children, body size, physical activity 相対的年齢効果，小学生，体格，身体活動 Ⅰ 緒 言 日本の学校は，4 月 1 日から新年度が始まり 3 月 31 日に修了する．ところが暦年齢の計算方法 はこの区切り方と異なり，民法 143 条では，年齢 は出生の日より起算し，起算日（出生日）に応答 する前日をもって満了し年齢が加算される，と定 められている．つまり，誕生日の前日に年齢が 1 つ加算されることになるので，学年は 4 月 1 日か ら次年の 3 月 31 日生まれではなく，4 月 2 日から 次年の 4 月 1 日生まれで区切られることになる． 誕生月のヒトへの影響については古くから研究 されており，1938 年に Huntington は，誕生月と 気候・地理的影響，寿命，リーダー性，才能など との関係について著書を出版している（Hunting-ton，1938） ．日本においては，三浦（2002）が胎児 期における日本脳炎の不顕性感染と感受性との関 連について指摘しており，1948-1964 年における 東京の患者（5-14 歳）を誕生月別にみると，日本 脳炎が流行する夏に誕生した子どもは他の月に生 ［原 著］ 発育発達研究 第 74 号

Does current behaviour predict the course of children's physical fitness?

“…We could show that PA has a direct positive influence on PF. The finding that the number of club sport activities has a direct influence on children's PF is consistent with the literature (Boreham & Riddoch, 2001;Deutscher Sportbund, 2003;Fogelholm et al, 2008;Hikihara et al, 2007;Magnusson et al, 2008;Sasayama et al, 2009). In our study, we show that PA has also an effect on the development of PF.…”

Socioeconomic position and childhood-adolescent weight status in rich countries: a systematic review, 1990–2013

“…The 158 papers that fulfilled the inclusion criteria are shown in Additional file 1 : Table S1. The studies came from the following countries: 48 from the USA [ 17 – 64 ]; 22 from the United Kingdom [ 65 – 86 ]; 18 from Germany [ 87 – 104 ]; 11 from Australia [ 105 – 115 ]; eight from France [ 116 – 123 ]; seven from Spain [ 124 – 130 ]; six from Canada [ 131 – 136 ]; five from Sweden [ 137 – 141 ], Greece [ 142 – 146 ] and Holland [ 147 – 151 ]; four from Belgium [ 152 – 155 ] and Italy [ 156 – 159 ]; two from Finland [ 160 , 161 ], Portugal [ 162 , 163 ], Denmark [ 164 , 165 ] and Ireland [ 166 , 167 ]; one from several countries [ 168 ] and one each from the Czech Republic [ 169 ], Iceland [ 170 ], Israel [ 171 ], Korea [ 172 ], Norway [ 173 ] and Switzerland [ 174 ].

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“…All the studies analyzed participants aged 0 to 21 years, except one in which the age range was 2 to 24 years: this was nonetheless included in our review because it did not present the data broken down by age [ 126 ]. Twenty one studies examined individuals of a single age [ 20 , 42 , 51 , 65 , 69 , 70 , 72 , 73 , 80 , 88 , 106 , 131 , 132 , 137 – 140 , 149 , 154 , 166 , 170 ]. Four cases [ 25 – 27 , 134 ] did not mention the individuals” ages but referred instead to their current school grade.…”

Different factors associate with body image in adolescence than in emerging adulthood: A gender comparison in a follow-up study

“…Presented data are the total time per day, from a weighted average of weekdays and weekend days, spent in moderate-to-vigorous activity (threshold 2000 counts per minute [cpm]; Troiano et al, 2008). A detailed protocol for measurements with accelerometers has been described previously (Magnusson, Sveinsson, Arngrimsson, & Johannsson, 2008). This particular type of accelerometer gives a reliable and valid measure of PA (Brage, Wedderkopp, Franks, Andersen, & Froberg, 2003) but is unable to measure all types of activity, e.g.…”