著者

Kuniko Moto Mika Goshozono Suguru Torii Akira Namba Motoko Taguchi

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.11, no.1, pp.35-42, 2022-01-25 (Released:2022-01-14)

参考文献数

37

被引用文献数

2

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Menstrual disorders are health problems in female athletes. It has also been reported that amenorrhea can lead to metabolic suppression. However, studies regarding resting energy expenditure (REE) in Japanese female athletes with menstrual disorders are lacking. The purpose of this study was to investigate whether REE was suppressed in female Japanese athletes with menstrual disorders. In total, 22 highly trained intercollegiate athletes participated in this study; and body composition, REE, thyroid and reproductive hormone levels, and nutritional intake levels were measured. Predicted REE (REEp) was calculated using two different equations based on fat-free mass (FFM) and organ-tissue mass measured by dual-energy X-ray absorptiometry (DXA). Individuals with menstrual disorders (MD group) had significantly lower height, body weight, and fat mass than those in the eumenorrheic (EU) group; however, the FFM did not differ between the groups. Both the measured REE (REEm) and REEm adjusted for FFM in the MD group were lower than those in the EU group. The REEm to REEp ratio, which indicates energy deficiency, was also lower in the MD group. In addition, although the MD group had lower triiodothyronine and progesterone levels, they were still within the normal range. Japanese female athletes with menstrual disorders may have lower REE than eumenorrheic athletes, even if thyroid and reproductive hormones are within the normal range.

著者

Naohisa NOSAKA Yoshie SUZUKI Akira NAGATOISHI Michio KASAI Jian WU Motoko TAGUCHI

出版者

Center for Academic Publications Japan

雑誌

Journal of Nutritional Science and Vitaminology (ISSN:03014800)

巻号頁・発行日

vol.55, no.2, pp.120-125, 2009 (Released:2009-05-12)

参考文献数

31

被引用文献数

2 20 20

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Medium-chain triacylglycerols (MCT) are known to hydrolyze readily and completely to fatty acids and to be metabolized more easily by β-oxidation than long-chain triacylglycerols (LCT). Therefore, we investigated the effect of 2 wk of ingestion of food containing a small amount (6 g) of MCT on energy metabolism during moderate-intensity exercise and high-intensity exercise in recreational athletes. For comparison, the subjects were administered food containing MCT or LCT for 14 d, and were instructed to perform cycle ergometer exercise at a workload corresponding to 60% peak O2 uptake (VO2) for 40 min followed by a workload corresponding to 80% peak VO2 until exhaustion. Blood lactate concentration, VO2, VCO2, and rating of perceived exertion (RPE) were measured at rest and during exercise. The exercise time to exhaustion at a workload corresponding to 80% peak VO2 was significantly (p<0.05) longer in the MCT trial (10.2±7.6 min; mean±SD) than in the LCT trial (5.8±3.3 min). Blood lactate concentration and RPE during exercise were significantly (p<0.05) lower after ingestion of MCT-containing food. Fat oxidation rate was higher and carbohydrate oxidation rate was lower during exercise in the MCT trial than in the LCT trial, but the differences were not significant. These results indicate that the ingestion of MCT-containing food may suppress utilization of carbohydrate for energy production because of increased utilization of fatty acids for generating energy. In conclusion, our data suggest that short-term ingestion of food containing a small amount of MCT suppresses the increase in blood lactate concentration and RPE during moderate-intensity exercise and extends the duration of subsequent high-intensity exercise, at levels higher than those achieved by ingestion of LCT-containing food.

著者

Naohisa Nosaka Yoshie Suzuki Hiromi Suemitsu Michio Kasai Kazuhiko Kato Motoko Taguchi

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.67, no.11, pp.1455-1462, 2018 (Released:2018-11-07)

参考文献数

32

被引用文献数

3 10

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Medium-chain triglycerides (MCT) are useful for increasing fat utilization during exercise. The highest rate of fat oxidation during submaximal exercise tends to precede the lactate threshold in untrained adults. In our previous study, blood lactate concentration was more than 4 mmol/L (onset of blood lactate) in recreational athletes during exercise at a workload corresponding to 60% peak O2 uptake (V・o2), which was below ventilation threshold. In the present study, we investigated the effect of 2 week of ingestion of food containing 6 g MCT on substrate oxidation during moderate-intensity (50% peak V・o2) exercise and high-intensity (70% peak V・o2) exercise in recreational athletes. For comparison, two experimental trials were conducted after participants had been administered isoenergic test foods (MCT-supplemented food with mainly maltodextrin-containing carbohydrate (MCT + CHO) or CHO) for 2 weeks, with a washout period between trials. Participants were instructed to perform cycle ergometer exercise at a workload corresponding to 50% peak V・o2 for 40 min followed by a workload corresponding to 70% peak V・o2 until exhaustion. Fat oxidation was significantly increased in the MCT + CHO trial (13.3 ± 2.7 g/40 min, mean ± SD, p < 0.05) during moderate-intensity exercise and the duration was extended significantly (23.5 ± 19.4 min, p < 0.05) during subsequent high-intensity exercise, compared with that observed in the CHO trial (fat oxidation; 11.7 ± 2.8 g/40 min, duration; 17.6 ± 16.1 min). In conclusion, continuous ingestion of 6 g MCT with maltodextrin could increase fat oxidation during moderate-intensity exercise and extend the duration of subsequent high-intensity exercise in recreational athletes, compared with the ingestion of isoenergic maltodextrin alone.

著者

Tatsuya Ishizu Suguru Torii Eri Takai Nozomi Miura Motoko Taguchi

出版者

The Japanese Society of Physical Fitness and Sports Medicine

雑誌

The Journal of Physical Fitness and Sports Medicine (ISSN:21868131)

巻号頁・発行日

vol.11, no.2, pp.107-116, 2022-03-25 (Released:2022-03-14)

参考文献数

51

被引用文献数

3

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The purpose of this study was to examine whether the bone parameters and food groups consumed differ according to the energy availability (EA) status in Japanese female athletes, and to determine the relationship between calcium intake and other food groups consumption among these athletes. We investigated EA status, nutritional and food group intake, bone metabolism using biochemical analysis, and evaluated body composition and bone parameters using dual-energy X-ray absorptiometry. Fifty-two Japanese female athletes (Age: 20.0 ± 1.2 years) were enrolled in this study. Group differences between the low EA (EA < 30 kcal/kg FFM/d, n = 22) and moderate EA (EA ≥ 30 kcal/kg FFM/d, n = 30) groups were examined. Compared to the moderate EA group, the low EA group exhibited a lower daily intake of protein (g/kg BW), carbohydrate (g/kg BW), calcium (mg), grains (g), meats (g), milk and dairy products (g). Moreover, the bone resorption marker was significantly higher in the low-EA group. The daily intake of soybean products (g), vegetables (g), fish and shellfish (g) and milk and dairy products (g) correlated positively with daily calcium intake (mg). Female athletes with low EA and insufficient intake of milk and dairy products exhibited increased serum tartrate-resistant acid phosphatase 5b levels. As with milk and dairy products intake, consumption of various food groups was also significantly positively correlated with calcium intake. These findings suggest that a diet with sufficient energy and multiple food groups to provide adequate calcium may benefit bone health among Japanese female athletes.