In Rocky IV, “Hearts on Fire” plays during Rocky’s Siberian training montage.
The song was written by Vince DiCola, Ed Fruge, and John Cafferty, and it was performed by Cafferty. Rocky trains in a remote snowy setting before his fight with Ivan Drago, using simple physical work such as chopping wood, running outdoors, and lifting improvised equipment.
The montage contrasts Rocky’s old-fashioned, self-directed preparation with Drago’s highly engineered Soviet training facility. Drago is shown surrounded by scientific equipment, computers, and monitored exercises, while Rocky trains with natural materials and local support. The musical sequence turns that contrast into one of the film’s best-known moments.
“Hearts on Fire” is not the same song as “Burning Heart,” which is performed by Survivor and also appears in Rocky IV. “Eye of the Tiger” belongs to Rocky III, making these songs easy to confuse across the franchise.