Is Dwayne Johnson's exercise regime really healthy?

The rock uses a host of different workouts to force his muscles to continue to grow. These are pyramid structured sets, reverse pyramid structured sets, straight structured sets. He also alternates different muscle groups. These include back legs, arms, chest, and abs, are performed twice a week with weighted swiss ball crunches.

Four sets x 25 peps. At four o'clock in the morning, he wakes up and has his coffee, and then he does cardio sessions. He warms up for about five minutes, and then he does about twelve minutes of high impact cardio, followed by a five-minute cooldown.