Phil Campbell, the author of Sprint 8 Cardio Protocol, is an exercise physiologist who specializes in speed training. Three decades ago he started experimenting with his own personal training regimen on a high intensity interval training (HIIT) program in order to improve upon anything else then available.
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“Sprint 8 is a tried and true workout that can rapidly and radically change your body for the better. It’s simple. It’s effective. And you’re going to love what it does to your body.”