This study investigated the acute effect of an 18-hole round of golf on serum interleukin-6 (IL-6) and brain-derived neurotropic factor (BDNF) concentration. Nine young, healthy males, unaccustomed to playing golf, completed an 18-hole round of golf (course length: 5,807 m.). Blood samples were collected prior to, immediately after and 1 h following completion of the exercise session. Interleukin-6 and BDNF, as well as creatine kinase (CK) and myoglobin concentrations were analysed in serum, while adrenaline concentrations were assessed in plasma. The participants completed the course in 303 ± 4 min. Serum IL-6 and BDNF concentrations were respectively elevated 8.6 ± 5.4-fold and 1.2 ± 0.3-fold immediately post-exercise (IL-6 p = 0.008; BDNF p = 0.038). Creatine kinase (p = 0.008), myoglobin (p = 0.011) and adrenaline concentrations (p = 0.038) were also acutely elevated following completion of the golf course. Creatine kinase and myoglobin concentrations were significantly correlated with the acute increase in IL-6 concentration post-exercise (r = 0.70 p = 0.034, r = 0.79 p = 0.012, respectively), while no such relationship was found for BDNF concentration. (r = 0.37 p = 0.333, r = 0.08 p = 0.833, respectively). An 18-hole round of golf was found to acutely elevate IL-6 and BDNF concentration in young, healthy males unaccustomed to playing golf. The correlation of CK and myoglobin with the acute IL-6 response suggests that muscle damage may have influenced the acute increase in this marker. Together, this pilot-study indicates that golf may be promoted as an accessible, low-intensity activity to acutely elevate markers suggested to stimulate improvements in metabolic health and cognitive function.

Japanese collegiate and club lacrosse games are often held under environmental conditions of extreme heat in the summer. Lacrosse players are also required to wear protective equipment, which is a risk factor for heat-related illness. Nevertheless, the thermoregulatory responses of lacrosse players under such conditions are poorly understood. The present study compared the thermoregulatory responses in subjects wearing the mens’ lacrosse uniform or general athletic clothes during an exercise-simulated lacrosse match played in the heat (high temperatures). Eight men performed two experimental trials of 4 × 15-min intermittent cycling exercise in the heat (35°C, 50% relative humidity). All participants performed two trials wearing a lacrosse uniform (WEAR) or general athletic clothes (CON). The physiological strain index was significantly higher (p < 0.05) in the WEAR condition than in CON, and exceeded the high risk level for heat-related illness in WEAR during the 3^rd quarter. Additionally, rectal temperature, skin temperature, heart rate, and ratings for perceived exertion, thermal sensation, and thermal comfort were significantly higher (p < 0.05) in the WEAR condition than in CON. Rectal temperature continued to increase during half-time in the WEAR condition, but not in CON (p < 0.05). These findings indicate that lacrosse players are at a higher risk of heat-related illness compared to other team sport athletes during a match because of the protective equipment worn, especially after half-time. Although further studies are required to confirm the thermoregulatory responses during an actual lacrosse match, our data will be useful in developing strategies to minimize the risk of heat-related illness.

In order to clarify the acute effects of exercise on the cold sensory function of cold-sensitive women, 12 young adult females with an awareness of cold constitution were subjected to two experiments: an exercise condition in which cycle exercise with a light-to-moderate intensity for 15 min was performed and a control condition in which rest without exercise was maintained in a crossover design. Cooling tests in which the hand was immersed in cool water at 15°C for 1 min were carried out before exercise, immediately after exercise, and 30 min after exercise, and the sensitivity of the cold sensory function was evaluated based on changes in skin temperature, thermal sensation, and comfort in the hand. In the control condition, cooling tests were performed at the same timing as in the exercise condition. Cold sensation and thermal discomfort during hand cooling were reduced by a significant increase (+0.5 ± 0.3°C) in core body temperature after exercise. Exercise did not alter the sensitivity of thermal sensation, but reduced the sensitivity of thermal comfort. These sensitivities remained unchanged throughout the control condition. A warm feeling increased in the trunk portion immediately after exercise, but a cold feeling in the foot decreased at 30 min after exercise. This suggested that the thermal sensation was affected in a site-dependent manner due to increases in core and skin temperatures after exercise, and that the sensitivity of cold-induced discomfort is transiently suppressed without altering the sensitivity of cold sensation.

Pelvic floor muscle training has been reported to be effective in preventing and improving urinary incontinence. Patients must learn to perform pelvic floor muscle contractions without pushing down the pelvic floor by contracting other muscle groups. This study aimed to determine the effect of maximal-effort contraction of the hip adductor and abductor muscles on the pelvic floor of young, healthy women. For these experiments, 23 healthy nulliparous women performed unilateral maximal-effort isometric contractions of the abductor and adductor hip muscles in a supine position. Simultaneously, the movement of the bladder’s posterior surface was measured using an ultrasonic imaging device. The displacement of the bladder base during maximal-effort contraction of the hip adductor/abductor muscles was calculated based on changes in the distance between the abdominal wall and the bladder base at rest. The results demonstrated that the bladder base significantly descended during maximal-effort isometric contraction of hip adduction/abduction. The maximal-effort isometric hip adduction/abduction muscle strength positively correlated with bladder base descent. These results indicated that isometric contraction of the hip adduction/abduction muscles under maximum effort pushed the pelvic floor downward. In pelvic floor muscle training, when the adductor and abductor muscles of the hip joint are contracted with maximum effort, the pelvic floor muscles cannot learn contraction and may inhibit movement.

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.

Physical fatigue accompanying athletic training has been a problem for ages. While salivary cortisol has traditionally been used to assess physical stressors, salivary human herpesvirus 6 and/or 7 (HHV-6/7) have recently been presented as novel microbiological markers. Thus, we examined differences in the short-term variabilities of salivary HHV-6/7 and cortisol levels in athletes. We collected saliva samples from 14 healthy male university judo athletes who participated in a three-day training camp pre- and post-training each day to measure salivary HHV-6/7 and cortisol levels. Simultaneously, the plasma superoxide dismutase (SOD) inhibition rates and total mood disturbance (TMD) scores in the Profile of Mood States were measured as indicators of physical and psychological stressors, respectively. The plasma SOD inhibition rates significantly increased post-training, but the TMD scores did not change; thus, the physical stressors were relatively higher than the psychological stressors during the training camp. Salivary HHV-6/7 levels increased post-training with a significant main effect of training, but no changes were observed in the daily levels. Only salivary HHV-7 levels showed a significant training × elapsed day interaction. Salivary cortisol levels showed a significant main effect of training, but its levels decreased post-training. These findings suggest that salivary HHV-6/7 are sensitive markers of physical fatigue more than salivary cortisol.

Endurance exercise induces skeletal muscle adaptations such as fiber-type switching, mitochondrial biogenesis, angiogenesis, and the enhancement of glucose disposal, all of which ameliorate metabolic dysfunction. Since many factors such as body temperature, pH, osmolality, the secretion patterns of neurotransmitters, and humoral factors, change during exercise, it is not easy to determine precisely how each factor contributes to exercise-induced adaptations. To determine these contributions, there is need for experimental studies using an in vitro muscle culture system focusing on a single added stimulus. In this study, we focused on whether contractile stimulation is itself responsible for inducing skeletal muscle adaptations. We constructed a chronic contraction model in mouse primary myotubes and investigated which type of contractile stimulation could induce muscle fiber switching and/or metabolic adaptations. We tested five sets of contractile stimulus conditions, including tetanus and twitch, for different stimulation periods. Of these, when myotubes were stimulated by 6 V/15 mA electric pulses at 1 Hz (20 ms contraction followed by 980 ms relaxation) for 24 hours, we observed a significant increase in the expression of myosin heavy chain (MyHC) I protein, a marker protein for type I (oxidative) myofiber, and a tendency for MyHC IIa expression to increase, a marker protein for type IIa fiber (the most oxidative myofiber out of the type II isoforms). However, the same conditions did not induce any change in the expression of GLUT4, COX IV, and hexokinase II, proteins related to the transport of glucose and metabolism. These results suggest chronic contractile stimulation does not induce the expression of proteins related to metabolism, but it does regulate the expression patterns of MyHC. This chronic contraction model has the potential to clarify the molecular mechanisms underlying the induction of oxidative myofibers in response to muscle contraction.