Changes in Brain Neutrophils and Neurological Function in Response to Acute Speed and Plyometric Training in Adolescent Boys

Neural activation is associated with increasing energy requirements, and increasing peripheral Lactate (LA) concentration in response to severe exercise, enhances LA supply as an energy substrate to meet acute neurological needs. The acute speed and football exercises may affect cognitive function by increasing LA concentration and nervous activation. Increasing the neurocognitive performance of growing adolescent boys plays an important role in their physical performance. Therefore, the aim of the present study was to investigate the effect of speed and plyometric training activity on the concentrations of nerve proteins in blood circulation.Although speed interval and plyometric training in football players may lead to progressive fatigue and activate the central nervous system and subsequent cognitive disorders, it may also positively increase neurotrophines such as BDNF or IGF-1 and affect brain neutrophils and neurological function. According to this evidence, we assumed that BDNF, BNG and IGF-1 increase in response to a football training session, which may be associated with increasing neurological function of adolescents. Therefore, the purpose of the present study was to investigate the effect of an acute speed and plyometric football-based exercise on plasma concentrations of BDNF, BNG and IGF-1 neural proteins, which may play an important role in enhancing cognitive abilities. And the effect of speed and plyometric training activity on the concentrations of nerve proteins in blood circulation.

The present study is a semi-experimental type with a pre-test and post-test design, which was conducted in two sessions, including an intervention and control session. After calling in Tehran's schools, 20 adolescents 14-15 years of age were selected and accessible as a sample, and randomly participated in 2 sessions of speed and plateometric exercises and control sessions. All subjects are familiar with how to perform speed exercises (RAST Test) during a familiarization period (two sessions). On the day of the main test, after 12 hours of fasting, the test was referred to the test site and the first blood sample (5 cc) was taken from the antiquiobital vein. After the standard breakfast of the subjects, we were wearing sportswear and after ten minutes of general warming up the speed training included six times a maximum of 35 meters with a 10-second recovery between each run. After the test was performed, the plyometric exercise was executed, including a pair jump and one -foot barriers, jump on barriers with 180 degrees rotation, zigzag jump and one foot forward, jump on  obstacles with both legs and legs Single-to-foot jumping on the barriers of single -foot and throwing a medicine ball, on the sides, with 12 repetitions. The active rest between turn was considered two to three minutes (29). The subject's heart rate was performed during the controlled exercise (Polar heart rate monitor) and the exercise in the range of 80-90 % of the heart rate. The second blood sample was taken immediately after the training session was completed. All sampling steps for each subject were performed under the same conditions and the BDNF and NGF levels were measured through the USA-made Kit. The IGF-I levels were measured through the ELISA methods and IGF-I Kit. Cognitive neurological function was also measured through the Stroop test (ST) before and after the training session. In this study, the Polish paper version of ST was used. ST consisted of 71 words written with colored ink. The task of the participants was to name the font color regardless of the written word. For statistical analysis, the research data are first described using the mean and standard deviation, then the changes before and after all the variables of the two sessions were calculated and analyzed using the dependent stroop test. A significant level was considered to be P≤0.05 and SPSS 16 was used to perform statistical calculations.

The mean and standard deviation of the somatic specifications of the research subjects was as follow: Weight (59.7±3.2), Body mass index (21.4±1.3), Fat percentage (21.7±2.8), and Fat free mase (41.10±4.1)The results of the present study showed that BDNF data changes were significantly different in training and control session (t19=12/89, p<0/001). In the exercise session, the BDNF rate increased by approximately 2.5 times compared with control session. NGF data also showed significant differences in both sessions before and after acute speed and Plyometric training (t19=4.89, p<0/001). Regarding the plasma levels of IGF-1 also the results showed a quite significant difference in comparison of two sessions (t19 =2.89, p=0.019).The time of implementation of the stroop test at two sessions of training and control in the preceding and later times also showed significant differences that in the exercise session the test was significantly reduced than the control session (t19 =3.89, p=0/009). The test time in the exercise session decreased from 59.3s to 53.1s. There was no significant change in the control session at the time of stroop performance (58.6 s and 59.3 s).These findings show that acute speeds and plyometric exercise are useful for improving post exercise cognitive performance in adolescent. Skeletal muscle contraction during high-intensity exercise increases BDNF levels in the brain, and the speed and plyeometric exercise protocol is a more effective and preferred intervention to raise BDNF levels than traditional exercise mode, with moderate intensity. Acute speed and plyometric exercises increase human cognitive function. Improvement of cognitive function may be the synthesis or release of neurological proteins that are adjusted by high blood LA after exercise.

In summary, the current findings suggest that acute plyometric and speed training enhances human cognitive performance. The improvement in cognitive performance may be from the synthesis or release of neuroprotective proteins modulated by high blood LA concentrations after exercise.