Introduction: Aerobic and anaerobic exercise capacity is essential to soccer players who need to repeat continuous and high-intensity movement for 90 minutes of soccer game. Inspiratory function has been known to be in charge of stable intake of oxyge...
Introduction: Aerobic and anaerobic exercise capacity is essential to soccer players who need to repeat continuous and high-intensity movement for 90 minutes of soccer game. Inspiratory function has been known to be in charge of stable intake of oxygen necessary for performance of exercise and contribute to the basic role for continuous performance of exercise, having an effect on the motor ability through delay of respiratory muscle fatigue and adjustment of metaboreflex in athletes. However, studies that have been conducted so far are limited to adult and elite groups, so studies targeting youth is considered necessary. Such studies are expected to be of help to improvement of aerobic and anaerobic exercise capacity and performance for youth soccer players. Accordingly, this study aims to examine the effects of inspiratory function on aerobic and anaerobic exercise capacity in youth soccer players.
Methods: Study subjects include 41 players in a youth soccer club(Age: 14 ± 1.0 yrs, Height: 162.4 ± 9.9 cm, Weight: 51.2 ± 10.4 kg). For diaphragm thickness, this study measured both resting and maximal inspiratory thickness of the left and right using ultrasound equipment. For measurement of maximal inspiratory pressure, this study found mean value after selecting only 2 maximum value with less deviation by measuring 3 time seach for 3 times using a Spirometer(POWER Breathe K5). VO2max was calculated by formula upon completion of 2.4km run test. Maximal lactate production rate was calculated by formula through measurement of maximal blood lactate concentration after 100m sprint test. For analysis of measured value, this study carried out One-way ANOVA and Kruskal-Wallis test for analyzing difference between position groups after Shapiro Wilk Normality Test. For analysis of correlation between variables, this study conducted Pearson’s correlation analysis and Spearman’s rank correlation analysis respectively. To analyze the effects of inspiratory function on aerobic and anaerobic exercise capacity, this study conducted the simple linear regression. Statistical significance level was set to 0.05.
Results: In regards to diaphragm thickness, maximal inspiratory pressure, VO2max, maximal lactate production rate in youth soccer players, no difference was found between position groups(p>0.05). In the diaphragm thickness on the right, negative correlation was discovered in the 2.4km Run time(r=-.346). And positive correlation was found in the diaphragm thickness and VO2max on the left and right respectively (r=.327, r=.336). Correlation between maximal inspiratory pressure and aerobic motor ability was not discovered. But negative correlation was found in the diaphragm thickness and 100m sprint time on the left and right(r=-.683, r=-.650). Correlation between diaphragm thickness and maximal lactate production rate was not discovered. And negative correlation was found between maximal inspiratory pressure and 100m sprint time(r=-.448). However, correlation between maximal inspiratory pressure and maximal lactate production rate was not found. And diaphragm thickness exercised an effect on 2.4km Run time and VO2max(R=-.346, R2=0.125, F=5.58, p<0.05), (R=.336, R2=0.132, F=5.938, p<0.05). Meanwhile, diaphragm thickness and maximal inspiratory pressure had an effect on 100m sprint timeR=-.650, R2=0.376, F=23.59, p<0.01), (R=-.448, R2=0.196, F=9.510, p<0.01).. Volume which is the variable of maximal inspiratory pressure affected maximal lactate production rate(R=.361, R2=0.130, F=5.846, p<0.05).
Conclusions: The results of this study significantly discovered the effects and correlation of inspiratory function on and with aerobic and anaerobic exercise capacity in youth soccer players. It is considered that diaphragm thickness and maximal inspiratory pressure that play a role of inspiratory function contributed to the role of stable intake of oxygen and basic respiration while exercising aerobic and anaerobic exercise capacity in youth soccer players. Therefore, consideration of inspiratory function is considered positively necessary for improvement of aerobic and anaerobic exercise capacity in youth soccer players. In addition to the foregoing, this study suggests training of inspiratory muscle for improvement of inspiratory function, which is expected to be a more effective training program for improvement of soccer performance.
Keywords: inspiratory function, diaphragm thickness, maximal inspiratory pressure, aerobic and anaerobic exercise capacity, VO2max, VLamax