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.

[Effects of gender-related weight reduction on the physical condition of male and female college judoists].

OBJECTIVE: In order to study the gender-related effects of weight reduction on the physical condition of male and female college judoists during weight reduction periods, we examined changes in anthropometric, nutritional intake and biochemical parameters in 43 male and female college judoists 20 days (pre-weight reduction) before and one day (post-weight reduction) before the game. METHODS: Subjects were divided into two groups. Thirty subjects (22 males, 8 females) who required weight reduction were defined as the weight reduction (WR) group, and the remaining 13 subjects (5 males, 8 females) were defined as the non-reduction (non-WR) group. RESULTS: In both WR groups, anthropometric parameters and nutritional intake significantly decreased after weight reduction compared to the pre-values. The change ratios of nutritional intake during the weight reduction period in the female WR group were higher than those in the male WR group. Serum lipids and electrolytes significantly decreased after the weight reduction compared to the pre-values in both WR groups. In the female WR group, Cr and UA significantly increased after the weight reduction compared to the pre-values. Although it was not significant, Ht increased after the weight reduction compared to the pre-values only in the female WR group. TP, Cr, UA, BUN, CK, LDH and IgA significantly increased after the weight reduction compared to the pre-values in the weight reduction compared to the pre-values in the male WR group. In contrast, in both non-WR groups, these parameters did not change significantly during the research period. CONCLUSIONS: Our findings suggest that nutritional exhaustion and dehydration may be the major effects brought about by energy and fluid restriction in female college judoists during a weight reduction period. On the other hand, in male college judoists undergoing weight reduction, the data suggest that muscle damage and myogenic protein catabolism may be caused chiefly by exercise. These differences may be due to the difference in the method of weight reduction for the different genders, namely, mainly exercise in males and mainly energy and fluid restriction in females.

The main neutrophil and neutrophil-related functions may compensate for each other following exercise-a finding from training in university judoists.

In order to clarify the relationship between exercise and neutrophil function, we measured three major neutrophil and neutrophil-related functions, viz. the reactive oxygen species (ROS) production capability and phagocytic activity (PA) of neutrophils and serum opsonic activity (SOA), simultaneously before and after a unified loading exercise under three different sets of conditions. Thirteen female collegiate judoists were examined with a unified exercise loading (2 h) immediately before and after a 64 day training period. Immediately thereafter, the athletes took part in a 6 day intensified training camp, following which the same exercise loading was repeated. Responses from circulating neutrophils were estimated by comparing the two sets of values obtained before and after the two instances of exercise loading. The parameters assessed included neutrophil count, SOA, PA and ROS production capability. ROS production increased after the exercise loading performed immediately before and after the 64 day training period just before the camp, (p < 0.01) but decreased following the exercise loading performed after the camp (p < 0.05). This suggested depressed bacteriocidal capability of the circulating neutrophils. PA decreased after the exercise loading sessions imposed prior to and after the 64 day training period (p < 0.01) but did not change in the loading session after the camp. No changes were seen in SOA produced with the loading exercise either before the 64 day exercise period or before the camp, but increased significantly following the post-camp session (p < 0.05). In conclusion, athletic training-induced changes in immune functional activities of neutrophils, such as ROS production and PA, and neutrophil-related factors, such as SOA, may compensate for each other to maintain the overall integrity of the neutrophil immune function.

Gender differences in the psychological response to weight reduction in judoists.

We examined gender-related differences in the psychological response to weight reduction in 43 judoists. Twenty-two males and 8 females who required weight reduction [weight reduction (WR) group] (the average percentages of weight reduction observed for males and females were 3.4% and 4.9%, respectively), and 5 males and 8 females who did not require weight reduction (non-WR group). The POMS scores were measured before and after weight reduction. The TMD (total mood disturbance) score in POMS significantly increased after weight reduction only in WR group males. In the female WR group, the anger and depression scores decreased after weight reduction, and the pre-value of the TMD score in thisgroup was relatively high. The psychological stress may be caused by anxiety engendered by the overall concept of weight reduction before actual weight reduction in females, whereas in males it may be caused by the actual weight reduction.

Effects of weight reduction on neutrophil phagocytic activity and oxidative burst activity in female judoists.

This study investigated the effects of short-term weight reduction on neutrophil functions in female judoists. Sixteen actively competing female judoists were divided into two groups. Eight who required weight reduction were defined as the weight reduction group, and the remaining eight were used as the control. Blood samples were taken before, immediately after and 8 days after the match. Phagocytic activity and oxidative burst activity of neutrophils were measured by flow cytometry. In the weight reduction group, the phagocytic activity per cell decreased significantly at the end of weight reduction compared with the control group. The rate of neutrophils producing reactive oxygen species and the oxidative burst activity per cell increased significantly at the end of weight reduction in both the control and the weight reduction groups. We concluded that weight reduction, consisting of both intense exercise and energy restriction, might possibly cause both an increase in oxidative burst activity and decrease in neutrophil phagocytic activity in female judoists. However, although exercise increased oxidative burst activity, it did not affect neutrophil phagocytic activity alone. Therefore, to avoid this problem, female judoists are recommended to keep their weight within those limits determined by their class, and which can be reduced by exercise.