Working out hard can be enough to drive anyone to drop the F-bomb, but it turns out doing so could actually be beneficial. Keele University researchers found that spewing out expletives while working out increases pain tolerance and triggers an adrenaline response. This in turn makes you work out harder, therefore maximizing your calorie burn. The scientists think we evolved so that swearing is used as a tool to withstand pain by triggering the “fight or flight” response.