Sonny Bill Williams is back for training after his injury. Photo / Twitter@SonnyBWilliams.
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.
The two-time Rugby World Cup winner is also seen performing some unorthodox-looking exercises sure to test the strength and flexibility in his lower legs, including one legged hopping drills, calf raises and attempting to walk across a tightrope strung low between two trees.
The code-swapping sensation - who could be sidelined from his new Super Rugby team the Blues up until May - spent the early part of the new year working out in Byron Bay in northern New South Wales, training alongside former professional rugby player turned personal trainer Ezra Taylor.
Taylor - who represented Otago, the Highlanders, the Queensland Reds and Manu Samoa - is one of the high-profile supporters of the Real Movement Project, a fitness initiative which includes a 28-day fasting diet.
Last week, Taylor shared a picture to social media of himself, Williams and Wallabies star Quade Cooper at Byron Bay, with the message: "An awesome couple of days spent with some special people."
Williams also features in a series of photos on the Real Movement Project's Instagram account.
The Real Movement Project states on its website: "Move, Nourish, Evolve. A movement of performance coaches reshaping the world."
During the first week of the programme, participants eat just one meal a day - with each meal high in fat, having moderate proteins and low in carbs.
Week two is a complete fast, with just water, multi-vitamins and electrolytes allowed. Participants are allowed one meal a day during week three.
The fourth and final week begins with a 40-hour fast, after which participants can eat one meal a day.
It is unclear if Williams' training with the Real Movement Project includes the fast.
But a post on the regime's website states: "Apply the mind, diet, movement and regeneration methods used by Sonny Bill Williams, Alastair Day and thousands of athletes and coaches around the world to become a better version of themselves."