The purpose of this study was to examine the effect of fructose ingestion on maximal exercise performance capacity following prolonged steady-state exercise compared with glucose or placebo ingestion, in 7 male college students (age 23.3±0.7 yr, height 171.3±1.9 cm, weight 68.4±1.4 kg, Vo2max 3.5±0.2 L/min, mean ± SEM) . The subjects cycled constantly on an ergometer at 59± 2 % Vo2max for 100 min divided in the middle by a 5-min rest, and then performed 10 min of all-out self-paced cycling. They ingested either 8 % fructose solution (F), 8 % glucose solution (G) or artifi-cially sweetened placebo (P) before and during exercise (at 20, 40, 65, 85 mm) . Before exercise and at 50 and 100 min of exercise and 5 min after the performance ride, blood samples were collected for determination of the concentrations of blood lactate, serum glucose and serum FFA. In the G trial, the serum FFA level was significantly lower than in the P and F trials at any of the time points dur-ing and after exercise (vs. P ; p<0.01, vs. F ; p<0.05) . However, glucose ingestion maintained serum glucose at a significantly higher level during and after exercise than placebo ingestion (p< 0.01) and improved the total work output in the 10-min performance ride (G vs. P ; 135± 8 KJ vs. 128± 8 KJ, p<0.05) . Although in the F trial, the serum FFA level was elevated during exercise compared to that in the G trial and the serum glucose level was significantly higher than in the P trial (vs. P ; p<0.01), the blood lactate level after exercise was lower than in the G trial and total work output was similar to that in the P trial (123± 8 KJ, vs. G ; p<0.01) . These results indicate that fructose ingestion before and during exercise cannot improve the ability to perform high-intensity exercise late in prolonged exercise despite maintaining the serum glucose level.

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本研究は, 日本人成人男女259名を対象に大腿部横断面の撮影と膝関節伸展・屈曲における等尺性最大筋力測定のフィールド調査を行い, 加齢に伴う大腿部筋群横断面積と筋力の変化について検討した.得られた結果は以下の通りである.
1) 膝関節伸筋群横断面積は, 男女とも60歳代で減少する傾向を示した.膝関節屈筋群横断面積は, 男性は60歳代までは加齢による変化はほとんどみられなかったが, 女性は20歳代が最も小さく, その他の年齢グループはほぼ同じだった.2) 膝関節最大伸展力において男性は, 60歳代で低下がみられたが, 女性は年齢による変化はみられなかった.また, 膝関節最大屈曲力において男性は40歳代から緩やかに減少する傾向がみられた.
3) 男性の大腿部伸筋群・屈筋群における単位横断面積当たりの筋力は40歳代頃から低下が始まることが示された.女性は伸筋群において20歳代, 30歳代がやや小さく40歳代から60歳代までは変化しなかったが, 屈筋群においては加齢とともに低下する傾向がみられた.
本研究の結果より, 本邦の男性においてはすでに50歳代頃から筋の構造・機能の低下が始まる可能性が示されたが, 女性は60歳代までは大きな変化は認められなかった.今後は, 高齢者のみならず, 高齢者予備軍である中年者にも筋機能低下防止のための運動処方を示すことが必要であり, そのことが将来にわたって高齢者の自立した日常生活獲得に貢献するものと考えている.

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To investigate the effect of teeth clenching on isokinetic knee extension at various velocities, isokinetic muscle strength during knee extension was measured in association with teeth clenching at 30, 60, 150, 300 and 450 degrees per second (deg/s) using the Cybex 6000 isokinetic dynamometer. The volunteer subjects were 9 healthy males (26.2±0.97 years) . The peak torque per body weight and average power per body weight were statistically analyzed. Our results demonstrated that the peak torque per body weight with teeth clenching at 30, 60 and 150 deg/s significantly increased by 7.0%, 7.4% and 4.9%, respectively (p<0.05), but no significant differences were found at 300 and 450 deg/s. While the average power per body weight with teeth clenching at 30, 60 and 150 deg/s significantly increased by 6.5%, 6.1% and 6.9%, respectively (p<0.05), no sig-nificant differences were found at 300 and 450 deg/s. A significant negative correlation was shown between the isokinetic angular velocity and the difference in peak torque per body weight derived from with and without teeth clenching (r=-0.699; p<0.05) . These findings suggested that the effect of teeth clenching on isokinetic muscle strength of knee extension was dependent on the angular velocity, and at lower angular velocities teeth clenching had the effect of increasing the isokinetic muscle strength during knee extension.

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本研究では, 小学校4年生男女児童を対象として, 校庭の「うんてい」施設を利用したうんてい移動遊びを1日5～10分間 (1人最低1回以上の実践) , 週5日の頻度で7ケ月間にわたり実施させ, その際における能動握力と受動握力への効果について検討した.おもな結果は, 以下の通りである.
1.7ケ月間のうんてい遊び期間中におけるうんてい移動達成者の比率は, 男子は50.0%から71.4%, 女子は58.8%から94.1%に向上した.
2.うんてい移動中における筋電図記録では, 手がバーを保持した瞬間とバーから離れる瞬間には上腕二頭筋と上腕三頭筋に一時的な強い放電, バーを保持している間は腕橈骨筋と橈側手根屈筋に持続的な筋放電が認められた.
3.7ケ月間のうんてい遊び終了時において, 運動群の能動握力は男女とも増加 (女子P<0.05) したが, 通常群とに有意差は認められなかった.これに対し, 受動握力は, 男女とも有意に増加 (P<0.01) し, 通常群とに有意差 (男子P<0.05, 女子P<0.01) も認められた.
4.7ケ月間のうんてい遊びによって, 上腕囲と前腕囲は有意な増加を認めなかった.
以上の結果から, 小学校児童における長期間のうんてい遊びの継続は, 能動握力よりも受動握力の向上に顕著な効果が認められ, それは筋肥大よりも神経系による影響がが大きいと推察された.

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本研究では, 漸増負荷法でのVO₂maxテストにおける運動中のVO₂の経時的変化および運動後の血中乳酸濃度からみた中距離走者と長距離走者の相違を明らかにし, 持久力のタイプを評価する新たな視点を提示することを目的とした.この課題を明らかにするために, 中距離走者9名, 長距離走者9名を対象として, 約11分間でexhaus-tionとなるような漸増負荷によるトレッドミル走を用いて, 走行中の酸素摂取量, exhaustion後の血中乳酸濃度などを測定した.また, VO₂maxの出現時間を, exhaustionに至った時間を基準として求め, 中距離走者の平均値で最も高いVO₂が認められたexhaustion前1.5分目からex-haustionまでの酸素摂取量の変化量 (ΔVO₂) も求めた.
本研究のおもな結果は次のとおりである.
(1) 中距離走者は長距離走者と比較して, exhaustion前のより早い段階でVO₂maxが出現し, その後の走行時間の長いことが認められた.
(2) 中距離走者は長距離走者と比較して, VO₂maxは有意に低く, 最大心拍数およびexhaustion後の血中乳酸濃度が有意に高いことが認められた.
(3) VO₂maxの出現時間の早い中距離走者は高い血中乳酸濃度を, 出現時間の遅い長距離走者は低い血中乳酸濃度を示す傾向が認められた.
(4) exhaustion後の血中乳酸濃度とΔVO2との間に, 有意な負の相関関係が認められた.上述の結果は, 漸増負荷法でのVO₂maxテストにおけるVO₂maxの出現時間, 最大心拍数および運動後の血中乳酸濃度などをもとにして, 中距離型の持久力と長距離型の持久力のような持久力のタイプを評価できる可能性のあることを示唆するものである.また, その背景の一つとして, exhaustion後の血中乳酸濃度の高いことがVO₂maxの出現条件に影響している可能性のあることを示唆するものである.

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To investigate effects of 1, 300 meters altitude on swimming training, several physiologic parameters were examined in eight female high school swimmers before, during and after living and training for six days at 1, 300 meters altitude.
Variables included peak heart rate (peakHR), rate of perceived exhaustion (RPE) and blood lactate concentration (BLa) associated with 200m swimming at submaximal and maximal speeds were measured 2-3 days before, during and 1-2 days after altitude exposure. Blood samples were collected before, during and after altitude exposure.
On day 1 of altitude exposure, peakHR and RPE at submaximal speeds increased from pre-altitude values while BLa didn't change. At maximal speed, swimming speed and BLa decreased, RPE increased, and peakHR didn't change from pre-altitude.
During altitude exposure, for the first three days of altiude exposure for peakHR and for all six days for RPE, the same submaximal speeds elicited greater values than pre-altitude.
Post-altitude BLa at submaximal speeds was reduced compared to pre-altitude. Maximal heart rate, RPE, and BLa at maximal speed didn't change pre- to post-altitude. However, mean values of them decreased from pre-altitude.
Erythropoietin was elevated above pre-altitude on day 2, and reticulocytes increased post-altitude significantly from pre-altitude.
These results indicate that the relative workload increased during the training at 1, 300 meters. There also appeared to be some stimulation for erythropoiesis.
In summary, this study found that 1, 300 meters altitude increased the difficulty of swimming training and six days at 1, 300 meters produced mild stimulation of erythropoiesis in these female swimmers

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本研究では, 運動形態, 運動強度, および流水速度について, 5種類の異なる水泳運動条件を設定し, 諸条件の変化が視覚に与える影響について検討を加えた.その結果,
1) 伏し浮きを行わせた静水条件における視覚機能は, 安静時と比較して変化が認められなかった.
2) 伏し浮きを行わせた静水条件と比較して, 伏し浮きを行わせた高速度流水条件, クロール泳を行わせた高強度運動条件では, コントラスト感度, 深視力などの視覚機能が低下を示した.
3) 主観的痛覚度は, 流水速度の増大にともない上昇した.これは角結膜上皮に障害が発生している可能性が考えられた.また, この時に観察された瞬目回数の増加は, その上皮障害を緩和しようとした結果であると考えられた.
4) 水泳運動に伴う視覚機能および視覚器の変化には, 流水速度の増大が関与していることが推察された.

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In order to find the cause behind the difference in the pattern of oxygenation between thigh and calf muscles during an incremental cycling exercise, we investigated the relationship between oxygenation and surface myoelectric activity. Five healthy male subjects performed the five 6-min cycling exercises of 50, 100, 150, 200 and 250 watts. We measured oxygenated hemoglobin/myoglobin (oxy-Hb/Mb) on continuous wave near infrared spectroscopy (NIR) and myoelectric activity with surface electrodes (EMG) . The NIR probe and electrodes were positioned on the vastus lateralis muscle (VL) and lateral gastrocnemius muscle (LG) of the right leg. The relative change in oxy-Hb/Mb was estimated by regarding the oxy-Hb/Mb level in the resting condition as 100% and that obtained during thigh occlusion as 0 %. The mean values of oxy-Hb/Mb and integrated EMG (iEMG) determined ranged from 5'30'' to 6'00'' at each work rate. In the VL, the oxy-Hb/Mb level decreased slightly at 50 and 150 watts (99.2±6.8% and 84.6±12.9%), followed by a more prom-inent decrease at 200 and 250 watts (74.9±11.9 and 65.2±9.6%) . The iEMG increased slowly at 50 and 150 watts (24.9±8.8 and 38.0±8.8μV), and a rapid increment occurred at 200 and 250 watts (49.6±13.0 and 57.3±19.6μV) . In the LG, however, the oxy-Hb/Mb level was decreased slightly at 50 and 200 watts (97.3±11.1 and 87.4±6.4%) and a rapid decrement occurred at 250 watts (74.1±6.0%) . The iEMG increased slowly at 50 and 200 watts (18.3±9.4 and 30.5±8.8 μV), and a rapid increment occurred at 250 watts (38.5±8.9 μV) . There was a significant negative correlation between the oxy-Hb/Mb level and iEMG in the VL (r=-0.587, p<0.001) and in the LG (r=-0.599, p<0.001) . From these results, we speculated that the difference in the relative change of oxy-Hb/Mb between the vastus lateralis and the lateral gastrocnemius muscle was due to the difference of increase pattern of muscle activity accompanied by an increase in exercise intensity in these two muscles.

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