Female rhythmic gymnasts with dietary problems are extremely conscious of their physical shape and often are diagnosed with iron deficiency (ID). Although there are several reports on training volume and quality throughout the year, there are few reports on the association between dietary intake and prevalence of ID. The aim of this study was to examine the association between the prevalence of ID, including erythropoiesis and hemolysis, and dietary intake for 10 months. A total of 19 Japanese collegiate elite female rhythmic gymnasts participated in five surveys in four different seasons: early pre-season (April), late pre-season (July and August), in-season (October), and off-season (January). Blood samples were collected to analyze body iron status including delta-aminolevulinic acid dehydratase (ALAD) activity, erythropoietin, and haptoglobin, and dietary intake were assessed. The definition of anemia was based on hemoglobin concentrations (<12.0 g/dL), and ID was diagnosed when one of the following clinical criteria or both were met: ferritin (< 12 ng/mL) and transferrin saturation (< 16 %). A higher incidence of ID (58%) was noted in July and August. ALAD was significantly higher in July to October than in April. Erythropoietin did not show any significant changes throughout the study. Haptoglobin was significantly lower in August than in January. Intakes of energy, protein, and iron were significantly lower in August than in April. Our findings suggest that inadequate intakes such as energy, protein and iron may concern with the high incidence of ID in August when the synthesis and destruction of red blood cells is enhanced in elite rhythmic gymnasts.
Abdominal bracing exercise is used to enhance all abdominal muscle activity. There are two methods of abdominal bracing— “activate the abdominal muscles without hollowing the lower abdomen” and “activate the abdominal muscles while inflating the lower abdomen”. Although the latter method is widely used in athletic fitness coaching, the electromyographic activities of the abdominal muscles in this method have not been measured yet. This study aimed to clarify the electromyographic activity of all abdominal muscles during abdominal bracing using the latter method of “activating the abdominal muscles while inflating the lower abdomen”. Thirteen healthy men (age: 22 ± 2 years) participated in this study. Transversus abdominis (TrA), internal oblique (IO), external oblique (EO), and rectus abdominis (RA) electromyography was recorded using an intramuscular fine wire and surface electrodes. The participants performed abdominal bracing and hollowing for 5 s (seconds) in six different positions. The electromyographic data during trials were calculated as a percentage of maximal voluntary isometric contraction (%MVIC). A two-way ANOVA was used to compare the %MVIC of each trunk muscle between abdominal bracing and hollowing among the six different positions. In TrA electromyography, there was no difference between abdominal bracing and hollowing. On the other hand, the activities during abdominal hollowing were significantly higher than those during abdominal bracing in IO and EO (p < 0.05). In RA, the activities during abdominal bracing were significantly higher than those during abdominal hollowing (p < 0.05). Abdominal bracing under the method of inflating the lower abdomen is not recommended for high activity of the IO and EO.
The amount of taurine and taurine derivatives in the body is affected by various diseases and physiological events, such as exercise. However, there is little information about possible changes in taurine distribution within tissue. In the present study, we examined whether matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) can be used to determine the effect of exercise on the distribution and content of taurine and acetyltaurine, a taurine derivative present in skeletal muscle. Using 9-aminoacridine to detect the amino acids in tissue samples, the content of taurine and acetyltaurine in homogenates of skeletal muscle was measured by MALDI-IMS. While the intrinsic levels of taurine in skeletal muscle tissue were adequate to be detected by MALDI-IMS, that of acetyltaurine was not observed. Following 120-min of treadmill running (20m/min), taurine content of soleus and plantaris muscles significantly declined. In the gastrocnemius muscle, taurine content is higher in slow-twitch fiber than fast-twitch fiber. However, the taurine content was not significantly changed by treadmill running in both fast- and slow-twitch fiber of the gastrocnemius muscle. In conclusion, MALDI-IMS using 9-aminoacridine as a matrix could detect the distribution of taurine in skeletal muscle before and after exercise.
This study was conducted to evaluate the influence of acute exercise on insulin secretion capacity and its underlying regulatory mechanisms in isolated pancreatic islets. Two groups of male C57BL/6J mice were assessed: a sedentary control group and a group that was subjected to a single 3-h (hour) period of swimming exercise. Immediately after the swimming exercise, an oral glucose tolerance test (OGTT) was performed and glucose-stimulated insulin secretion was assessed in isolated islets. The expression levels of proteins involved with insulin secretion were also examined in isolated islets. The areas under the curves (AUCs) for plasma insulin in the OGTT did not differ significantly between the control and exercise groups. However, the exercise group exhibited a significantly higher insulin secretion capacity of isolated islets relative to the control group (p < 0.05). Glucose transporter (GLUT)-2 protein, which is the predominant glucose transporter isoform in rodent pancreatic β cells, was expressed at a higher level in the exercise group relative to the control group (p = 0.05), but the expression of other proteins (i.e., markers of autophagy and intracellular Ca2+) were unchanged. These results indicate that the increased insulin secretion capacity following acute exercise is accompanied by increased GLUT-2 protein content.
Non-communicable disease (NCD) is now a burning public health issue in Bangladesh. Among crucial NCD risk factors, widespread low high-density lipoprotein cholesterol (HDL-C) levels is of top concern in Bangladesh. Over the last ten years, through an extensive nationwide investigation in Bangladesh, we found that more than 80% apparently healthy rural women in Bangladesh have low HDL-C levels. Thus, the present study investigated whether a lifestyle intervention program through daily walking could improve the low HDL-C levels in these women. A total of 231 rural women in Bangladesh were studied using an interventional approach, and analysis was performed based on a case-control design between low HDL-C and normal HDL-C. The subjects underwent a ten-week daily walking program (1.5 km walk twice a day). Among 231 participants at baseline, those with low HDL-C levels were 82.5%. Mean total HDL-C levels were 39.4 mg/dl in low HDL-C subjects and 56.1 mg/dl in normal HDL-C subjects, respectively, at baseline levels. The percentage of hypertriglyceridemia was 25.5% in low, and 10.3% in normal HDL-C subjects and the percentage of diabetes mellitus was 16.4% in low and 7.7% in normal HDL-C subjects before the exercise intervention. Although blood glucose levels and blood pressure were not changed significantly after the exercise intervention, low HDL-C levels were significantly improved with exercise (baseline, 39.8 ± 0.56; exercised, 46.3 ± 1.01, p < 0.001). The current research findings show that even a 10-week mild exercise program improved low HDL-C levels in rural Bangladeshi women, which can be a potential strategy for the prevention of NCD.
We investigated the effects of chronic pre-exercise acetate administration on body weight and metabolic adaptations to endurance training in ICR mice fed with either a normal fat diet (NFD) or high fat diet (HFD), respectively. Mice were divided into a control group (Con), an acetate group (Ace), a training group (Tra), and an acetate+training group (Ace+Tra) with NFD or HFD, respectively. Mice received orally either water or acetate (72 mg/kg body weight/day) for 4 weeks. The mice in the training group were subjected to training using a treadmill (20–25 m/min×60 min, 5 times/week) immediately after administration. As a result, in the NFD mice, there was no effect of acetate in any of the measurements. In the HFD mice, the final body weight in the Ace, Tra and Ace+Tra groups was significantly lower than the Con group. Moreover, the acetate treatment tended to decrease blood glucose concentration at rest. Gastrocnemius muscle glycogen concentration in the Ace+Tra group was significantly higher than that of the Ace and Tra groups. Unexpectedly, a significant negative main effect of acetate treatment in the maximal activity of β-HAD was observed, though the endurance training increased enzyme activity of citrate synthase in the plantaris muscle. These findings show the possibility that acetate treatment with endurance training shifts the metabolic characteristics of mice toward a carbohydrate metabolism against a lipid metabolism with the HFD condition, but not with the NFD condition.