Does respiratory muscle training improve respiratory functions and sport performance? : Review of the concept and directions for future research / 体力科学

<p>As the intensity of exercise becomes higher, increases in the oxygen uptake (VO₂) and cardiac output (Q) start to level off, and they will enter a steady state. However, the pulmonary ventilation (V_E) continues to increase in an exponential manner even after the VO₂ and Q level-off. After exercising to extreme fatigue, the oxygen used by the respiratory muscles (VO₂) increases to 10 to 16% of the VO₂max. In this situation, the respiratory muscles use the oxygen that would have been allocated to the active muscles because the oxygen used for the entire body is already in a steady state. Therefore, overexercising must be discontinued due to a shortage of oxygen for the active muscles (in the legs); amount of O₂ debt has reached its limit. Since the total amount of oxygen that can be taken into the body remains constant, the enhancement of the respiratory muscles and their functions (including the respiratory efficiency (V_E/VO₂)) in advance is expected to improve their endurance. Several previous studies suggested that respiratory muscle training (RMT) enhances the endurance of subjects. Furthermore, recent studies suggested that RMT not only enhances endurance, but also improves the physical elements of significantly intense exercise (including speed, muscle strength, and power) performed for a short period of time. It is necessary to conduct further research to clarify the mechanism of RMT in the improvement of physical performance. RMT is not expected to improve the VO₂max, and the following are possible causes of the improvement of performance: improvements in the respiratory muscles and efficiency (V_E/VO₂), a subsequent decrease in the blood lactate concentration, and subjective respiratory distress and sense of fatigue in the active muscles.</p>

Two Case Reports of Overtraining Syndrome with Anemia Successfully Treated with Ryo-kei-jutsu-kan-to / 日本東洋医学雑誌

Ryo-kei-jutsu-kan-to was used to successfully treat two cases of overtraining syndrome with anemia. The first case was an 18-year-old woman. Several years ago, she was diagnosed with iron deficiency anemia, and she took Fe pills intermittently. After university graduation in 1996, she began to experience lightheadedness and general malaise concurrently with increased training of long-distance running. In September of the same year, her anemia worsened, and she was introduced to our department. Administration of Ryo-kei-jutsu-kan-to improved her symptoms, anemia and maximal oxygen uptake. The second case was a 19-year-old woman. She was an office worker and a member of her company's athletic club. She became easily fatigued, and she came to our clinic in December of 1996. Hochu-ekki-to was administered and her fatigue improved. But in the following year she began to feel depressed and lightheaded, and she became anemic after increased increasing her training of long-distance running. Administration of Ryo-kei-jutsu-kan-to improved her symptoms and anemia.

Cross-sectional study on muscular endurance and blood flow of the human forearm with the male and female subjects aged 19 to 75 years / 体力科学

Muscular endurance and blood flow of the forearm were measured in 65 healthy male and 53 healthy female subjects, all aged 19-75 years. Muscular endurance was measured using a hand-ergometer with a load equal to 1/3 of the maximum grip-strength of the subject. The blood flow in the forearm was determined before and immediately after exercise using mercury-in-rubber strain-gauge venous occlusion plethysmography.<BR>The following results were obtained<BR>1) The muscular endurance of both the male and female subjects was observed to increase with age (p<0.05) .<BR>2) The forearm blood flow before exercise by the male and female participants was did not change with age (p>0.05) . However, the forearm blood flow immediately after exercise showed a tendency to increase with age in both groups (p<0.05) .<BR>3) A close relationship was found between muscular endurance and forearm blood flow immediately after exercise in both the male group (r=0.584, p<0.001) and the female group (r=0.776, p<0.001) .<BR>4) In forearm blood flow (both before and immediately after exercise) and muscular endurance, differences between male and female subjects in the same age group were not significant (p>0.05) .<BR>5) These results agree with some of the changes seen in the morphorogical muscle characteristics with aging.

PULMONARY DIFFUSING CAPACITY, PULMONARY MEMBRANE DIFFUSING CAPACITY AND PULMONARY CAPILLARY BLOOD VOLUME AT REST AND DURING EXERCISE / 体力科学

Oxygen intake, pulmonary diffusing capacity (DL), pulmonary membrane diffusing capac ity (DM) and pulmonary capillary blood volume (Vc) were measured at rest and during maximal and submaximal work, with Filley's steady state technique on 3 athletes (middle distance runners) and 5 non-athletes. The results obtained in this study were as follows<BR>(1) At rest, DL, DM, Vc in athletes were 28.3±3.7 ml/min/mmHg, 52.2±5.3 ml/min/ mmHg, 124.1±41.8 ml respectively, and in non-athletes were 25.6±1.0 ml/min/mmHg, 47.5±7.5 ml/min/mmHg, 114.7 ± 25.9m1 respectively.<BR>(2) During submaximal works, DL, DM and Vc increased together with oxygen intake. At the same level of VO<SUB>2</SUB> athletes showed greater DL, DM and Vc than those of non-athletes. Contact time exponentially decreased as oxygen intake increased.<BR>(3) At maximal work, athletes showed significantly greater max VO<SUB>2</SUB> DL, DM and Vc than those of non-athletes. But, contact time of athletes was not significantly greater than that of non-athletes.<BR>(4) The results demonstrate that a higher DL, DM and Vc is accompanied by a higher aerobic capacity, a larger ventilatory capacity, and a larger cardiac output.