The aim of this study was to identify performance-determining factors in biathlon standing shooting in rest and after intense exercise. Eight Finnish national- and nine junior-team biathletes participated in the study. Participants fired 40 resting shots (REST) and 2 × 5 competition simulation shots (LOAD) after 5 minutes of roller skiing at 95% of peak heart rate. Hit percentage, aiming point trajectory and postural balance were measured from each shot. Cleanness of triggering (ATV, movement of the aiming point 0-0.2 second before the shot) and vertical stability of hold (DevY) were the most important components affecting shooting performance both in REST (DevY, R = -0.61, P < .01; ATV, R = -0.65, P < .01) and in LOAD (DevY, R = -0.50, P < .05; ATV, R = -0.77, P < .001). Postural balance, especially in shooting direction, was related to DevY and ATV. Stability of hold in horizontal (F(1,15) = 7.025, P < .05) and vertical (F(1,15) = 21.285, P < .001) directions, aiming accuracy (F(1,15) = 9.060, P < .01), and cleanness of triggering (F(1,15) = 59.584, P < .001) decreased from REST to LOAD, accompanied by a decrease in postural balance. National- and junior-team biathletes differed only in hit percentage in REST (92 ± 8% vs 81 ± 8%, P < .05) and left leg postural balance in shooting direction in LOAD (0.31 ± 0.18 mm vs 0.52 ± 0.20 mm, P < .05), and the intense exercise affected the shooting technical components similarly in both national and junior groups. Biathletes should focus on cleanness of triggering and vertical stability of hold in order to improve biathlon standing shooting performance. More stable postural balance in shooting direction could help to improve these shooting technical components.