児童の水泳中の物理的・生理的運動強度に及ぼす着衣の影響

児童の水辺事故防止の観点から着衣泳と水着泳の関係を検討するために, 子供水泳教室に参加した児童61名の中から10名を選出し, 着衣が泳動作に及ぼす影響を, 物理的運動強度(泳速度・ストローク頻度・ストローク長)と生理的運動強度(心拍数)の観点から検討した。その結果, 次のような結論を得た。

1) クロールは水着では3泳法中最も速い泳速を示した。しかし, 着衣泳では水着泳の60%に泳速が激減し, 着衣の影響を最も顕著に受けやすい泳法であった。これは, ストローク頻度及びストローク長の双方が着衣泳で低下したためであった。

2) 背泳も着衣に大きく影響され, 着衣泳の泳速は水着泳の52%に低下した。ここでも, ストローク頻度及びストローク長双方の低下の影響を受けた。

3) 平泳は着衣泳において3泳法中最も速く, 着衣の影響が最も少なかった。平泳の場合には, ストローク長のみが低下して着衣泳の泳速が低下した。

4) 生理的運動強度としての心拍数は160拍/分前後であり, 泳法間及び着衣泳と水着泳の間に差はなかった。

5) 着衣による泳速の低下が最も少なく, 3泳法中最も速かった泳法は平泳であった。平泳は視覚も確保されるので着衣泳には一番適した泳法であると結論した。

With a view to Preventing young children from drowning accidents, 10 young children out of 61 who had participated in the swimming class, were selected at random to see how clothes affect swimming movement from both physical exercise intensity (swimming speed, frequency and stride of strokes) and physiological exercise intensity (heart rate) viewpoint. The results were as follows.

(1) Crawl stroke with the swimming wear on showed the fastest swimming speed among the 3 swimming strokes. With clothes on, the speed fell to 60% of the speed of the same stroke with the swimming wear on. Crawl stroke was most remarkably affected by clothes. That was caused by the declination of both frequency of strokes and stride of strokes.

(2) Back stroke was affected by clothes to a great extent. With clothes on, the swimming speed fell to 52% of the speed of the same stroke with a swimming wear on. In this case, the decrease of swimming speed was also caused by the declination of both frequency of strokes and stride of strokes.

(3) Breast stroke with clothes on was least affected among 3 swimming strokes. In the frequency of strokes, there was no difference between clothes and swimming wear on. Swimming speed of clothes declined for the declination of stride of strokes.

(4) Heart rate registered around 160 beats/min both in the case of swimming with clothes on and in the case of swimming with a swimming wear on. No major differece was noticed.

(5) Breast stroke was the one whose swimming speed was least affected by clothes and among the 3 swimming strokes it gave swimmers the fastest swimming speed with clothes on. Breast stroke also let swimmers have a better and wide view. Based on above results, it was concluded that breast stroke was the best swimming stroke in the case of swimming with clothes on.