Director Magnus van Horn tackles the emptiness of an Instagram-driven life in Sweat, the story of an ambitious young woman (Magdalena Kolesnik) who amasses 600,000 adoring followers as a love-spreading exercise guru. Kolesnik's Sylwia resides in the world of the selfie. She's all about appearances and the movie brings us into three days of a life that's both manically focused and weirdly unsettled. In its early going, Sweat functions as a near-blatant critique of a hyper but hollow existence, a condition emphasized by lots of hand-held camera work. Sylwia has an exercise pal (Julian Swiezewski), but she's mostly a solo act and her days seem to consist of striking a series of poses. Look, I'm making a shake now. In one of her endless videos, Sylwia admits to feelings of loneliness, which allows the movie to open the door to an underside that continues when Sylwia encounters a stalker who likes to watch her from his car while masturbating. A visit to her mother's birthday celebration shows how out-of-touch Sylwia can be with anything resembling normal interaction. I'm not sure that Van Horn deepens the movie enough but Kolesnik's performance drives Sweat through the burn of endless exercise and the pain of a life measured by online posts dealing with matters such as the virtues of climbing stairs rather than riding elevators. Sylwia's thousands of devotees can't alleviate her isolation or satisfy the glimmers of longing that even she can't suppress. But it's not clear that she'll ever be able choose moments of meaning if her 600,000 followers aren't watching.