Combining evolutionary biology with modern genetic science, Mark Sisson takes you back to basics and explains what you need to do to get the body and health you want - with the minimum amount of effort. Mark's approach works by adapting the simple practices of our early ancestors to our modern lifestyles.

Take Mark Sisson's 21-day Primal Challenge and watch the pounds begin to melt away. Based on 8 key concepts and 5 action items, Mark outlines a blueprint to get your health back on track - and your body fit and toned. Shed at least 2lbs of fat a week, get a stronger, leaner body, enjoy endless energy, develop an iron-clad immune system and improve health conditions.

In Keto for Life, Mark shows readers how to reset their biological clock in 21 days through a unique program that combines intermittent eating with strategies to lower inflammation and achieve metabolic flexibility. Readers will come to understand the Four Pillars of Longevity: Diet, Fitness, Mental Flexibility, and Rest and Restoration, learning best practices to slow the ageing process. Then they will carry out a 21-day Biological Clock Reset, with action items complete each day from each of the four pillars (including dietary practices, journal exercises, movement and routines, and...