Abdominal training: The 6 minutes of relentless pounding for the perfect 6-pack

Forget everything you knew about abdominal training. Today, Jeff becomes one with the floor and with science as his ally, he performs a highly painful but highly effective circuit core workout program with a focus on the abdominal muscles. The «euphoria, indeed, thou shalt not» (what's 6 minutes anyway?), but the intensity will push you to your limits. «What's the pain?’