As well as putting himself through brutal beech workouts, Sinckler has also been training in Brazilian Jiu-Jitsu.
The prop looks significantly leaner but still has the power required to be one of the best tighthead's in the world.
BEACH WORKOUT:
#2.Manu Tuilagi
The trimmed-down England centre has lost 2kgs after ending his guilty pleasure of binging on food.
Now off the crutches, the centre has continued to slim down as he looks to lessen his chance of injury.
Heading into the summer, Tuilagi tipped the scales at 114kg (17-stone 9lbs), but has lost six kgs [10lbs] and should drop a stone in weight once they are two or three games into the club season.
"I love my food. It is a mentality thing, you probably think you will be alright and you will get through it, until you think about it and you change your mentality.
"Running around for 80 minutes, those 2kgs can weigh you down quite a bit so we thought, lose a bit of weight and that would allow us to be a bit more mobile, a bit more agile."
#3.Sam Simmonds
Missing England's tour of Australia, the number 8 has been training hard as he looks to recapture his place in Eddie Jones plans for the Autumn Nations Series.
The Exeter mans place is under pressure following the world-class performances of Billy Vunipola against the Wallabies, playing a key role in their 2-1 series win.
A video made to promote stepone.life underwear appears to show a leaner Simmonds, who will be looking recapture his try-scoring form from the 2020/21 season.
Simmonds, who had bulked up significantly last season, appears to be getting back to the body shape that earned him a place on the 2021 Lions tour, but with bigger biceps.
#4.Joe Marler
He now looks almost unrecognisable from a year ago when the prop had put on a few extra pounds.
An image shared by stepone.life shows that the prop means serious business this season.
Jacob Stockdale looking a lot leaner in today's pics.
Jon Davies also looks a few kgs lighter this season.
Stuart Hogg lost stacks of weight to increase speed.
Wonder if it's the start of a trend for back?