If you went back to the gym this week, here’s Sonny Bill Williams' Beast-Mode workout to inspire you!

Video footage of rugby star Sonny Bill Williams has emerged showing the All Blacks midfielder in full beast mode as he battles back to full fitness.

Williams will miss the start of the 2017 season as he recovers from a partial rupture of his Achilles tendon suffered during the All Black Sevens' unsuccessful Olympic campaign in Rio.

But a compilation video of Williams working out in the gym and on the training field has him looking close to his physical best just nine days into the new year.

The 31-year-old looks a picture of health as he performs a mixture of low intensity movement and agility-based exercises as well as more intense resistance training using weights, bands and heavy balls.

- Herald on Sunday