成人男女の身体組成とその国際比較

Body composition of sixty-one Japanese men and sixty-two women aged 18 to 24 yrs. was determined by underwater-weighing method. Fat storage rate (%fat) was calculated using Brozek et al\u27s equation (1963). Mean values of %fat were 13.0% for men and 22.3% for women. Japanese men\u27s value was similar to South African\u27s. European\u27s, and Canadian\u27s, but lower than American\u27s. Women\u27s values were not very different from one another, excluding Indian\u27s. Adipose tissue mass (ATM) per 1 m of height in the present study were 4.7 kg/m for men and 7.5 kg/m for women, and the similar tendencies as %fat were found in ATM/height values in comparison with the previous studies. Namely, there were not so large differences in body fat between Japanese and other peoples. But, LBM/height in the present study were 31.2 kg/m for men and 25.6 kg/m for women, which were lower than those of most white peoples. This means that young Japanese adults have poor muscularity

ポジション別にみた大学ラグビー選手の身体組成、形態、筋機能、栄養素摂取量の特徴

Rugby players play different roles according to their playing positions. Playing position is a key factor for players to increase or maintain their physical capacity. This study investigates body composition, anthropometric characteristics, muscular function and dietary intake of varsity rugby players, and examines the differences due to the playing position. The subjects were sixteen male varsity rugby players; seven forward players (FW) and nine back players (BK) aged 18.3±0.6 yrs. The results showed no significant differences of body composition, subcutaneous fat thickness and girth of circumference between FW and BK. Significant differences (p<0.05) were found between FW and BK for isokinetic leg strength (extension: FW=3.1±0.3Nm/kg, BK=3.5±0.4Nm/kg, flexion: FW=1.8±0.2Nm/kg, BK=2.0±0.1Nm/kg) and grip strength (FW=542±66Nm, BK=448±74Nm). But there were no significant differences between FW and BK for back strength, leg extension power, and maximal anaerobic power. Furthermore, dietary intakes were not significantly different. A lot of previous studies with senior players reported clear differences for body composition, anthropometric characteristics and muscular function due to playing positions. In this study, however, the subjects did not show the similar results as senior players. These differences are considered to come from in-maturity of the subjects for their playing positions. The most adapted physical characteristics of rugby player due to playing positions probably appear in/after university life with hard training and enough dietary intakes

運動後の回復にみるヘルストロンの効果に関する研究

The purpose of this study was to examine the effect of Healthtron^【○!R】 on recovery after exercise. Seven subjects, three men and four women with averaging 22.1 yrs. of age, performed three cycling exercise tests at 60% VO_ for 15 minutes. After exercise, subjects engaged in three recovery conditions for 30 minutes. These recovery conditions consisted of sitting rest (SR), sitting on Healthtron (HT), followed five-minute cycling (0W) and sitting rest (light exercise : LE). Heart rate and blood lactate concentration were measured before the exercise test, immediately after, and 5, 10, 20, and 30 minutes after exercise. Heart rate increased (p<0.05) due to the exercise and returned to the pre-exercise level five minutes after exercise during each recovery condition. Blood lactate concentration (La) increased (p<0.05) with exercise in each recovery condition. After five-minute exercise, La returned to the pre-exercise level in HT and LE, but not in SR. The rate of La decrease after exercise in HT was larger than those in LE and SR, and all the subjects in HT showed a similar decreasing trend along with 30-minute recovery. These results lead to the conclusion that Healthtron promotes effective removal of blood lactic acid after moderately intense exercise

Development of pericardial fat count images using a combination of three different deep-learning models

Rationale and Objectives: Pericardial fat (PF), the thoracic visceral fat surrounding the heart, promotes the development of coronary artery disease by inducing inflammation of the coronary arteries. For evaluating PF, this study aimed to generate pericardial fat count images (PFCIs) from chest radiographs (CXRs) using a dedicated deep-learning model. Materials and Methods: The data of 269 consecutive patients who underwent coronary computed tomography (CT) were reviewed. Patients with metal implants, pleural effusion, history of thoracic surgery, or that of malignancy were excluded. Thus, the data of 191 patients were used. PFCIs were generated from the projection of three-dimensional CT images, where fat accumulation was represented by a high pixel value. Three different deep-learning models, including CycleGAN, were combined in the proposed method to generate PFCIs from CXRs. A single CycleGAN-based model was used to generate PFCIs from CXRs for comparison with the proposed method. To evaluate the image quality of the generated PFCIs, structural similarity index measure (SSIM), mean squared error (MSE), and mean absolute error (MAE) of (i) the PFCI generated using the proposed method and (ii) the PFCI generated using the single model were compared. Results: The mean SSIM, MSE, and MAE were as follows: 0.856, 0.0128, and 0.0357, respectively, for the proposed model; and 0.762, 0.0198, and 0.0504, respectively, for the single CycleGAN-based model. Conclusion: PFCIs generated from CXRs with the proposed model showed better performance than those with the single model. PFCI evaluation without CT may be possible with the proposed method

Hyperoxic Training Results in Greater Training Effects on Cardiorespiratory Function and Metabolism than Normoxic Training

高酸素気吸入下および正常気吸入下での身体トレーニングが, 有酸素能力および代謝に及ぼす影響を明らかにするために, 14名の健康な男子大学生がトレーニング実験に参加した。被検者を任意にVO_がほぼ同じくらいになるように高酸素気吸入下での身体トレーニング群 (HT群 : n=7, VO_=54.7ml・kg^・min^), 正常気下での身体トレーニング群 (NT群 : n=7, VO_=54.6ml・kg^・min^) に分け, 自転車エルゴメーターを用いて90%VO_の強度で週3回, 4週間のトレーニングを行った。トレーニング時間はHT群では1回につき12分間, NT群では総仕事量を同じにするために12分24秒から13分6秒の範囲であった。また, 漸増負荷法による最大運動テストと90, 150および210Wで3分間, 合計9分間の最大下運動テストをトレーニング前後に行った。その結果, トレーニング後, HT群ではVO_が54.7から60.2ml・kg^・min^に, NT群では54.6から56.8ml・kg^・min^に増加した。両群の増加率を比べてみるとHT群 (10.0%) の方がNT群 (4.2%) よりも有意に大きいことが明らかになった。また, トレーニング後, HT群では最大下運動テスト時の呼吸交換率および血中乳酸濃度が有意に低いことが明らかになった。これらのことから, 高酸素気吸入下での身体トレーニングはVO_を改善する点, 最大下運動時において糖質の消費を抑制し, 脂質の利用を促進する点で有効なトレーニングと考えられる。To determine the physiological effects on aerobic capacity and metabolism of hyperoxic and normoxic training, fourteen healthy male college volunteers participated in the training study. The training intensity and period were 90%VO_ and 3 days per week for 4 weeks. Subjects were divided into a hyperoxic training group (HT group : n=7, VO_=54.7 ml・kg^&lt-1&gt・min^&lt-1>), and a normoxic training group (NT group : n=7, VO_=54.6 ml・kg^・min^) according to their VO_. The training duration in the HT group was 12\u2700", and that in the NT group ranged from 12\u2724" to 13\u2706" in order to equalize the amount of work performed by the two groups. Maximal and submaximal graded exercise tests were conducted at pre- and post-training. At post-training, VO_ in the HT group was increased from 54.7 to 60.2 ml・kg^&lt-1>・min^. VO_ in the NT group was also increased from 54.6 to 56.8 ml・kg^&lt-1>・min^. The change ratio of VO_ (ΔVO_) in the former group (about 10.0%) was significantly larger than in the latter group (about 4.2%). At post-training, respiratory exchange ratio and blood lactate concentration during the submaximal exercise test in the HT group were significantly lower than in the NT group. These results indicated that hyperoxic training was more useful for improving the VO_ and might inhibit carbohydrate consumption and promote lipid utilization

水中トレッドミルを用いた水中歩行・走行の生理学的応答

The aim of this study was to clarify the physiological characteristics of the underwater treadmill at varied treadmill speeds to compare to the land treadmill with the focus especially on the middle-aged people. Seven healthy middle-aged volunteers and ten regularly trained athletes participated in this study as the subjects. The treadmill speeds were set at six speeds ranging from 2 km・h^ to 12 km・h^. The water depth was around waist-high and water temperature was kept around 29℃ throughout the experiments. VO_2 did not significantly differ between the underwater treadmill trails to the land trails for middle-aged volunteers while regularly trained athletes showed significantly greater VO_2 in water (4, 6, 8, 10 and 12 km・h^). In water, middle-aged volunteers showed VO_2 at their highest treadmill speed was about 93% of the land VO_ and regularly trained athletes\u27 VO_2 was about 86% of the land VO_. Underwater running using the underwater treadmill thus promises to be one of the new types of fitness or training program for both middle-aged people and regularly trained athletes. In water, the relation-ship between HR and % VO_ showed no significant difference from the land treadmill trails both in middle-aged volunteers and regularly trained athletes. Therefore, at waist-high immersion, the effects of hydrostatic force of water may be negligible so the relationship between HR and VO_2 of the land locomotion may be applied to underwater locomotion

スポーツ活動時のエネルギー消費量推定のためのHR-VO_2関係式作成のプロトコールの検討

本研究の目的は, HR-VO_2関係式によってスポーツ活動時のエネルギー消費量を推定する際, 漸増負荷法によって作成した式だけでなく, 漸減負荷法によって作成した式も組み合わせて利用することの有効性を検討することであった。方法は, 負荷の設定以外をできるだけ等しい条件にし, 3種類のプロトコールによって毎分50回転に規定した自転車こぎ運動を行った。このうちの2つはHR-VO_2関係式を作成するためのものであり, 4分間ごとの漸増負荷法 (UP式) と, 4分間ごとの漸減負荷法 (DOWN式) であった。そして残りの1つは, スポーツ活動を想定した負荷の増減が繰り返される運動であり, この時の酸素摂取量をUP式とDOWN式のそれぞれの関係式によって求めるとともに, 算出すべきある時点の心拍数が, 直前の1分間値と比較して, 上昇あるいは同じ場合にはUP式を, 下降した場合にはDOWN式を用いる2つの式を組み合わせた方法 (U-D式) の合計3種類の方法によって推定し, 実測による値との比較を行った。結果は, U-D式が最も実測値に近い値を得ることができた。したがって, 心拍数からスポーツ活動時のエネルギー消費量を推定する場合には, 漸増負荷法と漸減負荷法による2つのHR-VO_2関係式を組み合わせることが, より実測値に近い値を得るのに有効であると考えられる。It is very difficult to estimate the intensity of sports activity by heart rate with a HR-VO_2 relationship because intensity of the sports activity during a game is undulatory. This study aimed at establishing the validity of estimated energy consumption with combined applications of HR-VO_2 relationships under stepwise increased workloads (UP-formula) and stepwise decreased workloads (DOWN-formula). Nine male physical education majors pedaled a bicycle ergometer under undulatory workloads for 16 min. Oxygen uptake was estimated from UP-formula, DOWN-formula and combination usage of UP and DOWN formulas. Results showed that the estimated value with combination usage was nearest to the actually measured value. It was concluded that combination usage is more valid than single use of the UP or DOWN formulas in estimating energy consumption of sports activity

旅行者血栓症 (いわゆるエコノミークラス症候群) 対応座席についての生理学的検討

Traveler\u27s thrombosis has posed a severe problem around the world. Much research has been conducted to find effective approaches to traveler\u27s thrombosis. We examined a proto-type ankle exerciser equipped on a plane seat in order to assess its effectiveness. The purpose of the first study is to determine a suitable exercise tempo. Three tempos of 30, 60, and 90 times per minute were examined with young male and female subjects by measuring heart rate and blood pressure during five-minute exercise. Heart rates at 90 times per minute were higher than those of other tempos. Blood pressure did not show any differences among the three tempos. We determined 60 times to be the suitable tempo because of the mildness and smoothness of the exercise. The second study is on changes of calf circumference during two-hour sitting and five-minute exercise. Calf circumference after two-hour sitting showed an increase of 1.4% in young male subjects, and 2.2% in young female subjects. The five-minute exercise made for a 0.5% decrease in men and a 1.3% decrease in women. There was a 0.9% improvement by each the exercise. Middle-aged men and women, however, did not show any improvement after exercise. The third study was on skin temperature and blood flow in the foot during two-hour sitting and five-minute exercise. Three of all six subjects showed a clear decrease in foot temperature during sitting and an increase during exercise. The results of two subjects, however, were contrary to the above-mentioned results. The temperature of another subject fluctuated up and down during sitting, and then steeply increased during exercise. Blood flow during exercise increased three to ten times in comparison with sitting. These results lead to the conclusion that the proto-type ankle exerciser connected to a plane seat might serve to prevent traveler\u27s thrombosis