The Hercules actor stopped by NBC's Tonight Show Tuesday, where he joined the host for some silly exercise skits. Johnson set the segment up by saying he first got interested in fitness after watching the Fungo brothers' VHS tape. "They were really ahead of their time," Fallon joked. "All the fitness trends over the years—the Thighmaster, the Shake Weight—these guys did it first. They were never quite successful but they were always so close to the next big thing. It's amazing they never got credit for it."
Fallon then accessed the "vintage" clips via NBC's computer database.
Enter mop-topped fitness duo Jeff and Tad. "Do you wanna run faster do you want you your legs that will cause disasters and glutes that are harder than plaster?" Jeff (Fallon) asked. "You gotta get the thigh cruncher." Tad (Johnson) added, "You'll know it's working when you feel the burn between your legs."
They ended the demonstration with their catchphrase: "You've gotta hustle for the muscle!"