No, from the half-shutter press the focus is set. This is true in burst mode too. I would say to manually set the ISO up higher, but understand this will add some noise to the image. My other suggestion would be to just fully press the the shutter button from the get-go. That way there's very little lag from focus to shoot. Also, try the scene mode "Kids and Pets" as this assumes action and so adjusts the camera accordingly. Also, try shooting in burst mode just in case your blurriness is coming from your shutter finger shaking.