Yousuke Yamamoto

Exercise training and energy restriction decrease neutrophil phagocytic activity in judoists.

PURPOSE To investigate the effects of weight reduction as the result of exercise training and energy restriction on neutrophil function. METHODS Eighteen male competitive college judoists participated in the study. In a whole blood assay, oxidative burst activity, phagocytic activity, expressions of Fc gamma receptor 3 (CD16), and complement receptor 3 (CD11b) of neutrophils were measured on a per cell basis by flow cytometry at day 20, 5, and 1 before and at day 7 after the competition. RESULTS The rate of neutrophil producing reactive oxygen species decreased before the competition, whereas the oxidative burst activity per cell increased significantly in all subjects, which resulted in a significant increase of the total oxidative burst activity. However, there were no significant effect of energy restriction on oxidative burst activity. The rate of neutrophils incorporating opsonized zymosan decreased significantly with energy restriction. The total phagocytic activity of 10,000 neutrophils and the phagocytic activity per cell also decreased significantly by severe energy restriction. The surface antigen expressions of CD11b and CD16 were unaffected by weight reduction. CONCLUSIONS The results suggest that with respect to the management of health conditions, weight reduction for judoists should be composed of exercise training and energy restriction should be moderate.

Differences In Fat-free Mass And Muscle Thicknesses At Various Sites According To Performance Level Among Judo Athletes

The purpose of this study was to investigate differences in fat-free mass and thicknesses of various muscles among judo athletes of different performance levels. The subjects were 69 male judo athletes of 3 different performance levels. Group A was composed of athletes who participated in the Olympic Games or Asian Games (n = 13). Groups B(n = 21) and C (n = 35) were composed of judo athletes at a university who did or did not participate in intercollegiate competitions (including qualifying matches), respectively. Muscle and fat thicknesses were measured by B-mode ultrasound at 9 sites. Fat percentage was calculated from fat thicknesses using a previously reported equation. Fat-free mass was calculated from fat percentage and body weight. Muscles thicknesses were normalized to the height of the individual. Group A had significantly larger fat-free mass than Group C (p < 0.05). The normalized thicknesses of the elbow extensor and flexor muscles were significantly larger in Group A than in Group C. The normalized thickness of the elbow flexor muscle was significantly larger in Group A than in Group B. The results of this study showed that judo athletes with low performance levels such as those in Group C had lower fat-free mass, and the degree of development of the brachialis muscles differed according to performance level.

Change in the capability of reactive oxygen species production by neutrophils following weight reduction in female judoists

Objective: Athletes undergoing weight reduction are recognised as being more prone to infection. Few studies exist for athletes on the weight reduction-mediated changes in neutrophil function and related activities such as reactive oxygen species (ROS) production capability, phagocytic activity (PA) and serum opsonic activity (SOA). Methods: 16 Japanese female university judoists were examined in the early morning of the first day (pre-values) and the last day (post-values) of a 20-day pre-competition training period. Of the 16 subjects, 8 needed to reduce weight (WR group) and the other 8 did not (control group). The parameters assessed were the neutrophil count, serum immunoglobulins and complements, myogenic enzymes, ROS production capability, PA and SOA. Results: Comparing the post-values with the pre-values, ROS production significantly increased in both groups (p<0.01 for both). PA significantly decreased in the WR group (p<0.05); it also decreased in the control group but the decrease was not significant. SOA significantly increased in the control group (p<0.05), but showed no significant change in the WR group. Conclusions: The changes in the WR group were probably a direct consequence of the weight-reduction regimen coupled with the exercise regimen, suggesting that neutrophil parameters (ROS production, PA and SOA) had tended to deviate from their typical compensatory changes to maintain immune system homoeostasis.

Development of predictive equations for body density of sumo wrestlers using B-mode ultrasound for the determination of subcutaneous fat thickness.

Objective: To develop an equation for predicting the body density of sumo wrestlers. Methods: The following were measured: subcutaneous fat thickness measured at nine sites using B-mode ultrasound equipment; circumference at seven sites; hand to leg bioelectrical impedance. The subjects consisted of 24 college sumo wrestlers (mean age 19.7 years, mean body weight 111.2 kg) and 24 matched obese controls (mean age 19.1 years and mean body weight 111.2 kg). In addition, body density was measured by the underwater weighing method, and the percentage of fat was calculated from the measured body density. Results: Linear regression analysis was used to estimate the relation between body density and other variables, and a predictive equation for the body density was derived: y = 1.088−0.00036 × (fat thickness at nine sites) (r2 = 0.90) for the sumo wrestler group and y = 1.083−0.00033 × (fat thickness at nine sites) (r2 = 0.91) for the control group. A multiple regression analysis was performed using the body density as the objective variable, and other measured items as the explanatory variables. This was used to derive a predictive equation: y = 1.121−0.00038 × (fat thickness of abdomen)−0.00043 × (circumference of hips)−0.00142 × (fat thickness of triceps) (r2 = 0.94) for the sumo wrestler group, and y = 1.076−0.00070 × (fat thickness of abdomen)−0.00140 × (fat thickness of tibialis) (r2 = 0.91) for the control group. The difference between the two equations was due to the difference in body fat distribution. Neither of these predictive equations is applicable to non-overweight non-athletes. Conclusion: This is the first predictive equation developed for the body density of sumo wrestlers.

Effects of long-term training on neutrophil function in male university judoists

Objectives: To clarify the effects of high-intensity and high-frequency long-term/chronic training on neutrophil function and serum levels of myogenic enzymes in male university judoists. Methods: The subjects were 24 male judoists who had stopped judo training for 6 months and then restarted their training. The following parameters were examined before and after a 2 h unified exercise loading (UEL) at the beginning of the restarted quotidian training (pre-training) and at 2 months, 4 months and 6 months thereafter: myogenic enzymes, neutrophil and leucocyte counts, and neutrophil phagocytic activity (PA) and oxidative burst activity as a measure of reactive oxygen species (ROS) production capability. Results: Myogenic enzymes that were measured after UEL at all four points significantly increased except for creatine kinase at the 2-month point (p<0.01 in each) and neutrophil counts significantly increased after UEL at the pre-training, 2-month and 4-month points (p<0.01 in each), but these changes became smaller from the 2-month point. PA significantly decreased after UEL at the pre-training and 2-month points (p<0.01 in each), but no change was seen at the 4-month and 6-month points. On the other hand, no change in ROS production per cell after UEL was seen at the pre-training point, but it significantly increased after UEL at the 2-month, 4-month and 6-month points (p<0.01 in each). Conclusion: The changing rate of the levels of UEL-mediated myogenic enzymes, neutrophil mobilisation and neutrophil function was seen to decrease at the 2-month, 4-month and 6-month assessments, compared with the pre-training point: these may comprise at least some of the long-term training effects.

The effects of a two-hour judo training session on the neutrophil immune functions in university judoists

The present study examined the effects of judo training on neutrophil and related functions. We measured and studied changes in the neutrophil and its related functions in 22 male university judoists immediately before (Pre values) and immediately after (Post values) a 2 h training session: reactive oxygen species (ROS) production capability, phagocytic activities (PA) and serum opsonic activity (SOA). Neutrophil count in whole blood, myogenic enzymes (creatine kinase, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase), immunoglobulins (IgG, IgA and IgM) and complements (C3 and C4) in serum were also measured. The Post values of the neutrophil count, myogenic enzymes and IgG increased significantly compared with the Pre values. ROS production capability and SOA also significantly increased following training, although PA showed a slight decrease (but not statistically significant). Taking the findings of our previous studies into consideration, three major neutrophil or related functions, namely ROS production capability, PA and SOA, might compensate for each other to maintain the overall integrity of the neutrophil immune function, in that ROS and SOA increased to compensate for the slight decrease in PA, or PA slightly decreased to compensate for the increase in ROA and SOA after exercise.

Measuring neutrophil functions might be a good predictive marker of overtraining in athletes.

In order to develop a predictive marker of overtraining in athletes, we examined the changes in neutrophil function [reactive oxygen species (ROS) production capability and phagocytic activity (PA)] for 10 male and 13 female judoists attending a training camp. Measurements were taken four times in total--immediately before and after a 2 h unified exercise loading (UEL) performed 1 day before (Pre-Camp) and the day after the 7 day training camp (Post-Camp). UEL-mediated aspartate aminotransferase was higher at Post-Camp than at Pre-Camp in females but not in males. Post-Camp leukocyte/neutrophil counts after the UEL significantly increased in females but not in males. The rate of change in C4 was significantly smaller in females than in males at Post-Camp. Only ROS significantly decreased without any compensation (increase in PA) being made at Post-Camp in females. In conclusion, this finding, namely that ROS significantly decreased only at Post-Camp without any compensatory mechanism (increase in PA), would suggest that the training camp imposed greater loading on females than males. This consideration was supported by the atypical aspartate aminotransferase, leukocyte/neutrophil counts and C4 findings which were seen at Post-Camp only in females. Therefore, regularly examining neutrophil functions such as ROS and PA might be a good preventative measure against overtraining in athletes participating in training camps.

Effect of glutamine supplementation on neutrophil function in male judoists.

Glutamine is an important amino acid for immune function. Though high intensity and prolonged exercise decreases plasma glutamine concentration and causes immune suppression, the relationship between neutrophil functions and glutamine has not yet been found. The purpose of this study was to investigate the impacts of glutamine supplementation on neutrophil function. Twenty-six male university judoists were recruited. Subjects were classified into glutamine and control groups. The glutamine group ingested 3000 mg of glutamine per day and the control group ingested placebo for 2 weeks. Examinations were performed at the start of preunified loading exercise (pre-ULE), then 1 and 2 weeks after ULE (post-ULE). Reactive oxygen species (ROS) production, phagocytic activity, serum opsonic activity and serum myogenic enzymes were measured. Differences between the levels obtained in pre-ULE and post-ULE for the two groups were compared. In the glutamine group, ROS production activity increased 1 week after ULE, whereas it was not observed in the control group (P < 0.001). Though myogenic enzymes increased significantly after ULE (P < 0.001), the glutamine group remained unchanged by supplementation during ULE. Glutamine supplementation has prevented excessive muscle damage and suppression of neutrophil function, especially in ROS production activity, even during an intensive training period.

Influence of a 3-month training program on muscular damage and neutrophil function in male university freshman judoists.

We studied the effects of a high intensity and high frequency 3-month training program on muscle damage and neutrophil function in male judoists. The study included 15 male judoists who started intensive judo training program after a 6-month break. Creatine kinase (CK), neutrophil counts and reactive oxygen species (ROS) production capability as well as phagocytic activity (PA) of neutrophils were measured at 2 stages; entering university (pre-training) and after 3-month training (post-training). At both points, we investigated parameters three times: just before, immediately after and 24 h after a 2-h practice session. Practice-mediated change in CK was lower at post-training than at pre-training. Neutrophil count significantly increased after 2-h practice but recovered 24 h later whereas it showed no subsequent and further increased at 24 h post-practice. Although neutrophil ROS production capability and PA both decreased (breakdown) after practice session, ROS production capability increased and PA decreased (well-adapted) at the post-training. Long-term training strengthened muscular function and improved neutrophil reaction against practice-mediated stress.

Gender Differences in Physical and Psychological Stress Responses among College Judoists Undergoing Weight Reduction

Gender-related differences in anthropometry, blood biochemistry, psychological parameters, and energy intake during prematch weight reduction were studied in 22 men and 7 women college judoists who lost weight by combining judo training, restricting food and fluid, and sweating. Body weight (BW) decreased significantly by 2.2±1.4 kg in men and 2.0±1.4 kg in women 2 weeks after weight reduction started — not significandy different. Body fat, relative body fat and total energy intake also decreased significandy in both groups 2 weeks after weight reduction started. Lean body mass decreased significandy 2 weeks after weight reduction started only in men. Men had significantly decreased blood lipids, immunoglobulins, complements, hematocrit, white blood cell count, and serum electrolytes, and significant increases in blood uric nitrogen, creatinine, and hemoglobin, while women showed no such changes. The score for vigor in the Profile of Mood States (POMS) decreased in both groups 2 weeks after weight reduction started, but with no statistically gender difference. In women, scores for anxiety in the State-Trait Anxiety Inventory (STAI) and confusion in POMS increased significandy. Although the men and women had the same BW reduction, significant physical stress response was seen only in men, and psychological stress due to weight reduction and mental pressure of an upcoming competition were seen more in women.