This article discusses the validity of slow jogging and introduces ideas for authors seeking an ideal weight reduction method, based on slow jogging and the science of sports nutrition, as a tool in fighting obesity and improving athletic performance, which are common goals in developed countries.

Skeletal muscle is a critical organ for generating force. To increase muscle mass effectively and to maximize performance, the combination of resistance exercises with skill training is important. Nutritional intake, especially protein, stimulates muscle protein synthesis within 1 to 2 hours. This anabolic response is induced mainly by leucine, which is an essential amino acid. An increase in the blood leucine concentration leads to muscle protein synthesis. Resistance exercise is another intervention that acutely increases muscle protein synthesis. Resistance exercise-induced augmentation in muscle anabolism depends on the force-time integral （load × contraction time）. Therefore, low-intensity resistance training with a high number of repetitions until failure can induce as much muscle hypertrophy as that achieved using high-intensity exercise. There should be three considerations in respect to protein intake with resistance exercise: 1） the additive effect of protein intake is most prominent when provided immediately after exercise, but protein intake for up to 24 hours after exercise can still induce a significant additive anabolic effect, 2） the dose-response relationship of protein intake reaches a plateau with 20 to 25 g of high-quality protein, and 3） the quality of protein （i.e., the leucine content as well as the absorption of the protein） can affect post-exercise muscle protein synthesis significantly.

【Aim】

This study aimed to develop and validate scales for assessing the stage of change (SOC) and self-efficacy (SE) of college athletes regarding their eating habits.

【Method】

Sixty-six college track and field athletes participated in this study, which examined SOC and SE scales for eating habits. The validity of the SOC scale was checked by measuring its correlation with the “actual versus estimated required intake.” For the SE scale, the internal consistency was estimated using the Cronbach alpha measure, and its validity was checked by separately examining its correlation with the “SOC,” “level of satisfaction with dietary pattern,” “access to information,” and “actual versus estimated required intake.”

【Results】

A correlation between the SOC and the intake of vegetable dishes was observed, revealing that the college athletes tended to eat less than the estimated required amount of vegetables. A factor analysis resulted in a SE scale with 19 items and a 5-factor structure. Each factor had a Cronbach alpha above 0.70. A criterion-related validation revealed a correlation between Factor 1 and “SOC,” while Factor 2 was separately correlated with the intake of “Grain dishes,” “Fish and Meat dishes,” and “Energy intake.” Factor 3 was separately correlated with the intake of “Milk” and “Fruits.”

【Conclusion】

This study developed and validated a scale for assessing the SOC for the intake of vegetable dishes, as well as a SE scale consisting of 5 factors pertaining to the eating habits of athletes. The results suggest that these scales might be useful as nutritional education instruments.

To develop a novel method of promoting glycogen recovery, we examined the effects of the co-administration of glucose and milk on insulin secretion and glycogen resynthesis in muscle and liver after exercise in C57BL/6J mice. In Experiment 1, non-exercised mice were orally administered a glucose solution (2 mg/g body weight [BW], CHO group), milk (40 µL/g BW, Milk group), or milk containing glucose (CHO-Milk group). Blood samples were collected from the tail vein, and the levels of plasma glucose, insulin and glucose-dependent insulinotropic polypeptide (GIP) were determined. Compared with the CHO and Milk groups, the CHO-Milk group had a significantly higher plasma insulin level and a lower glucose level after administration. Furthermore, the plasma GIP concentration was significantly higher in the CHO-Milk group and was positively correlated with the plasma insulin concentration. In Experiment 2, mice performed an acute bout of 30-min running exercise and were then orally given a milk and/or glucose as in Experiment 1. At 60 min after administration, the glycogen concentrations in the muscle and liver were significantly higher in the CHO-Milk group than in the CHO group. These results suggest that the co-ingestion of glucose and milk stimulates insulin secretion via gut-derived GIP and promotes muscle and liver glycogen resynthesis after exercise in mice.

To maximize the rate of muscle glycogen recovery, athletes are recommended to consume a sufficient amount of carbohydrate within 30 min after the exercise. The purpose of this study was to reevaluate the effects of the time of carbohydrate intake on the post-exercise glycogen resynthesis rate in mouse skeletal muscle. Male ICR mice were subjected to 60-min running exercise and then were orally administered a glucose solution (2 mg of glucose/g body weight) either immediately (0 min) or 30, 60 or 120 min after the exercise. At 2 h after the glucose administration, the tibialis anterior muscles were dissected out and the muscle glycogen concentrations were determined. The muscle glycogen resynthesis rate during the 2-h recovery period was significantly higher for the mice administered with glucose solution immediately after the exercise, compared with those fed at 30, 60, or 120 min after exercise. While no significant differences in phosphorylation statuses of AMP-activated protein kinase and glycogen synthase were seen, the increase in the plasma glucose level (area under the curve [AUC] of plasma glucose) was significantly higher for the mice administered immediately after exercise, compared with the other groups. In addition, a significant correlation was observed between the plasma glucose AUC and the muscle glycogen recovery rate. These results suggest that even a 30-min delay in the intake of carbohydrates resulted in a slower rate of muscle glycogen recovery after exercise. Furthermore, the higher rate of post-exercise glycogen resynthesis induced by the earlier ingestion of glucose appears to be caused by increases in intestinal glucose absorption and glucose availability in the systemic circulation.

【Objective】

This investigation evaluated the effects of a nutritional education program on the parents of junior golfers and the junior golfers themselves in terms of their knowledge, consciousness, and behavior concerning food.

【Methods】

The subjects were 38 children and their parents living in the Kanto area of Japan. Ten parents and their children served as the control group (CONP and CONC), and 28 parents and their children served as the intervention group (INTP and INTC). Before participating in the nutritional education program, all the parents completed a survey regarding the dietary intakes of their children. The INTP group then received health guidance from a registered dietitian regarding the individual dietary needs of each child and attended 4 lectures held over a 2-month period. Changes in nutritional knowledge and behavior were then assessed at 9 weeks after the start of the program.

【Results】

The INTP group exhibited improved social support (p = 0.001), self-efficacy (p = 0.001) and stage of change (p = 0.002) scores. Moreover, knowledge of recommended recovery snacks (p = 0.035) and recovery snacks (p = 0.014) was significantly better in the INTC group than in the CONC group.

【Conclusion]

Parents exhibited remarkable improvements in social support, self-efficacy, and stage of change after completing a nutritional education program. In addition, the parents were strongly motivated to improve their knowledge of recovery snacks for their children．

The Female Athlete Triad, an interrelationship of low energy availability, menstrual dysfunction, and low bone mineral density, is prevalent in sports activities. Because estrogens have a pivotal role in an extensive range of physiological functions regulating cellular homeostasis and energy metabolism, estrogen insufficiency caused by menstrual dysfunction leads to systemic health problems including metabolic dysfunction. We investigated the effect of prolonged estrogen insufficiency on skeletal muscle in young ovariectomized (OVX) female mice. Estrogen insufficiency resulted in muscle atrophy, reduced muscle force generation and a shift to a faster fiber type distribution. Population expansion of muscle stem cells, called satellite cells, was significantly reduced in OVX mice. Indeed, muscle regeneration was markedly impaired by a decrease of estrogen levels. Together, these results suggest that estrogens are essential for comprehensively maintaining muscle function with its insufficiency affecting muscle force and regeneration in young female mice. Here, we review recent progress in our understanding of the roles of estrogens in muscle function, and discuss nutritional interventions to prevent and treat the Female Athlete Triad.