Cilem diplomove prace bylo zjistit u basketbalistu kategorii U14 a U16, zda se vprubehu soutezniho obdobi meni tuhost dolnich koncetin (LS) a reakcni silovy index (RSI) jako indikatory svalove unavy. Studie se zucastnili basketbaliste v kategorii U14 (n=24) a v kategorii U16 (n=24). Obe kategorie hracu byly nasledne rozdeleny na vyssi (Prostejov, U14A a U16A) a nizsi (Olomouc, U14B a 16B) uroven. Testovani probehlo na zacatku, uprostred a na konci sezony. Vysledky ANOVY ukazaly signifikantni rozdily mezi hodnotami RSI na zacatku, uprostred a na konci herni sezony (F=4,48, p=0,014, 2=0,15). Post-hoc test ukazal vyznamne vyssi hodnoty RSI na konci sezony oproti zacatku u hracu kategorie U16A (p=0,019) a U16B (p=0,04). Naopak hodnoty relativni LS oproti zacatku na konci sezony vyznamne poklesly u hracu kategorie U16A (p=0,02) a U16B (p=0,04). Vysledky ANOVY rovnez prokazaly signifikantni rozdily RSI mezi kategoriemi U14 a U16 (F=13,36, p=0,001, 2=23). Post-hoc test ukazal rozdily na zacatku (p=0,04 a p=0,04), v polovine (p=0,037 a p=0,039) i na konci sezony (p=0,001 a p=0,02). Nebyla jednoznacne potvrzena kumulace neuromuskularni unavy u hracu na konci herni sezony. Zlepseni urovne sledovanych indikatoru unavy nervosvaloveho aparatu kolenniho kloubu svekem bylo potvrzeno jen v pripade RSI. Nebyl potvrzen rozdil mezi hraci nizsi a vyssi urovne u obou souteznich kategorii.The objective of the diploma thesis was to find out, in basketball players of categories U14 and U16, whether the leg stiffness (LS) and the reactive strength index (RSI) as indicators of muscle fatigue change during the competition period. The study involved basketball players of U14 category (n=24) and U16 category (n=24). Both categories of players were further divided into a higher level (Prostejov, U14A and U16A) and a lower level (Olomouc, U14B and U16B). Testing took place at the beginning, in the middle and at the end of the period. ANOVA results showed significant differences between RSI values at the beginning, in the middle and at the end of the competition period (F=4,48, p=0,014, 2=0,15). The post-hoc test showed significantly higher RSI values at the end of the period as compared to the beginning in players of categories U16A (p=0,019) and U16B (p=0,04). On the contrary, the relative LS values at the end of the period dropped significantly in categories U16A (p=0,02) and U16B (p=0,04) if compared tothebeginning of the period. ANOVA results also showed significant differences of the RSI between categories U14 and U16 (F=13,36, p=0,001, 2=0,23). The post-hoc test showed differences at the beginning (p=0,04 and p=0,04), in the middle (p=0,037 and p=0,039) and at the end of the period (p=0,001 and p=0,02). The accumulation of neuromuscular fatigue in players atthe end of the competition period was not conclusively confirmed. Theimprovement of the level of monitored indicators of fatigue oftheneuromuscular apparatus of the knee joint with age was confirmed only in case of the RSI. The difference between the lower and the higher-level players in both competition categories was not confirmed.