FLUKTUACIJE U SRČANOJ FREKVENCIJI I SPOLJAŠNJIM ZAHTEVIMA U ODNOSU NA PERIOD IGRE U FUDBALU

This study aimed to investigate fluctuations in external demands and heart rate (HR) response across two game periods (half-times) in recreational football players. Eighteen recreationally active, male college students (goalkeepers: n = 2; outfield players: n = 16; age: 20.9 ± 1.5 yr; height: 179.4 ± 5.0 cm; body mass: 76.9 ± 8.1 kg; fat mass: 15.3 ± 5.5%) participated in this study. Two sessions were used to administer 4-a-side small-side games (SSG). Differences in activity demands and HR response were analyzed using a paired sample t-test. The magnitude of the differences in each dependent variable was quantified with effect size (ES) analyses and interpreted as: trivial, 2. An ES analysis showed, small to moderate, significant decreases in distance covered at 0-6.00 km·h-1 (ES = -0.54, small), 6.01-12.00 km·h-1 (ES = -0.99, moderate), 12.01-18.00 km·h-1(ES = -0.66, moderate), >24 km·h-1 (ES = -0.72, moderate), total distance (ES = -0.91, moderate) and high-intensity accelerations (ES = -0.60, moderate) during the second rather than the first half. In addition, unclear significant decreases in HRmean, and percentage of time spent working 81-90% HRmax were observed across two game periods. Our findings indicate game-related fatigue, whereby players demonstrated a consistent HR response across two game periods despite diminutions in activity demands during the second half. Similarities in HR response across two game periods might be due to the lower physical fitness of recreational players, eliciting slower HR recovery.Cilj ove studije bio je da se istraže fluktuacije u spoljašnjim zahtevima i srčanoj frekvenciji kroz periode igre kod fudbalera rekreativaca. Osamnaest rekreativno aktivnih studenata muškog pola (golmani: n=2; igrači: n=16; starost: 20.9 ± 1.5 god.; visina: 179.4 ± 5.0 cm; telesna masa: 76.9 ± 8.1 kg; masna masa: 15.3 ± 5.5%) je učestvovalo u ovoj studiji. Dve sesije su korišćene za igru 4 na 4. Razlike u spoljašnjim zahtevima i srčanoj frekvenciji analizirane su t-testom zavisnih uzoraka. Veličina razlike u svakoj zavisnoj varijabli je kvantifikovana efektom (ES – effect size) i interpretirana kao: trivijalna, 2. Analiza veličine efekta pokazala je mala do umerena, značajna smanjenja u predjenoj distanci brzinom 0-6.00 km·h-1 (ES = -0.54, mala), 6.01-12.00 km·h-1 (ES = -0.99, umerena), 12.01-18.00 km·h-1 (ES = -0.66, umerena), > 24 km·h-1 (ES = -0.72, umerena), ukupnoj distanci (ES = -0.91, umerena) i visoko intenzivnim ubrzanjima (ES = -0.60, umerena) u drugom poluvremenu u odnosu na prvo. Pored toga, uočeno je nejasno značajno smanjenje srčane frekvencije i procenat vremena provedenog u radu 81-90%HRmax kroz periode igre. Nalazi studije ukazuju na umor uzrokovan igrom, pri čemu su igraču pokazali konzistentnu srčanu frekvenciju uprkos smanjenju spoljašnjih zahteva tokom drugog poluvremena. Sličnosti u srčanoj frekvenciji kroz periode igre mogle bi biti posledica manje fizičke spremnosti rekreativnih igrača, izazivajući sporiji oporavak srčane frekvencije