Natural Force is the second studio album by Welsh singer Bonnie Tyler, released in May 1978 by RCA Records. In the United States, the album was titled It's a Heartache. As with her debut, Ronnie Scott and Steve Wolfe wrote most of the tracks on the album. David Mackay returned again to produce, with Scott and Wolfe. Other songs include covers of American artists Stevie Wonder and Carole King.Five singles were released from Natural Force.