A pulley device includes a strap loop, a cord-securing component and cord respectively attached to the strap loop, a pulley component, the cord attached to the pulley component. The pulley component includes a housing, and may include a wheel that rotates within the housing. The wheel may have a circumferential groove or flat circumferential side to accommodate a cord or belt. The cord may form a loop, enabling the cord loop to be secured on the cord-securing component so that the pulley device may be worn on a person's wrist.