The symptoms of anemia, decreases in the levels of circulating red blood cells (RBC), hemoglobin (Hb) and hematocrit (Ht) lead to decrease endurance performance, and the risk of anemia increases in female endurance athletes. Although Hb is composed of a large amount of amino acids, the relationships between circulating levels of amino acids and RBC, Hb and Ht in female endurance athletes have not been clarified yet. Thus, the purpose of the present study was to investigate the relationship between circulating levels of amino acids and RBC, Hb and Ht in female endurance athletes. Twenty-four female endurance athletes (19.8 ± 0.2 years) participated in this study. We measured circulating levels of RBC, Hb and Ht from blood. Also, we measured circulating levels of amino acids from plasma by use of comprehensive analysis. The levels of circulating RBC, Hb and Ht in all subjects were within the normal range. We found that circulating taurine levels were significantly correlated with RBC (r = 0.48, p < 0.05), Hb (r = 0.44, p < 0.05) and Ht (r = 0.42, p < 0.05) in female endurance athletes. In the present study, we demonstrated that circulating taurine levels were significantly associated with RBC, Hb and Ht in female endurance athletes. These results suggest that circulating taurine levels may be a predictor of anemia and treatment strategy for anemia.

Premenstrual syndrome (PMS) that occur during late luteal phase is a problem for many female athletes. Many studies reported that subjective condition is affected by PMS in female athletes. Moreover, female athletes with PMS have higher stress and/or anxiety levels during luteal phase compared with non-PMS athletes. However, the relationship between PMS and physical performance in female athletes are not clarified yet. The purpose of this study was to investigate the relationship between premenstrual syndrome (PMS) and jump performance in female track and field athletes. Sixteen participants who has natural basal body temperature pattern with the menstrual cycle (observed low-temperature and high-temperature phase), were participated in this study. PMS was assessed by ACOG’s premenstrual syndrome questionnaire. As physical performance, counter movement jump (CMJ) and rebound jump (RJ) were evaluated in low-temperature phase and high-temperature phase. The result of this study, no significant differences were observed in body composition and physical performance between low-temperature phase and high-temperature phase. However, compared with participants who had non-symptom, participants who had a breast tenderness of PMS showed larger decreases in jump height of CMJ (p = 0.038) and RJ index (p = 0.015) in high-temperature phase. Therefore, PMS may have a negative effect on physical performance during high-temperature phase in female athletes.

Arterial stiffness in endurance athletes is low, whereas arterial stiffness in strength athletes is high. The adaptation of the arterial stiffness may be different depending on the training type. On the other hand, there are mixed-trained athletes that can’t be classified as endurance- or strength- trained athletes. The aim of this study was to investigate the arterial stiffness among mixed-trained athletes. The total of 51 young male athletes (15 long-distance runners, 10 handball players and 26 kendo players) and 16 young healthy sedentary individuals (control group) participated in this study. Carotid-femoral pulse wave velocity (cfPWV), carotid-brachial PWV (cbPWV) and femoral-ankle PWV (faPWV), were measured as indices of central and peripheral (upper and lower limbs) arterial stiffness, respectively. cfPWV showed significantly lower in long-distance runners (high endurance capacity) and handball players (strength and high endurance capacities) compared with kendo players (strength and low endurance capacities) and control groups (P < 0.05 for both). cbPWV showed significantly lower in handball players and kendo players compared with the control group (P < 0.05 for both). There was no difference in faPWV among the groups. These data suggest that the competitive characteristics of athletes (i.e., endurance capacity or target muscle groups of sport) influence the adaptation of arterial stiffness. It can be speculated that endurance capacity in mixed-trained athletes can affect central arterial stiffness and similar to endurance trained athletes. In addition, the adaptation in upper limb arterial stiffness will be included in the training effects associated with the sports-specific target muscle groups, while lower limb arterial stiffness may not be unaffected by any type of exercise.