Neymar has already begun training alone in his home city of Santos despite not being required to join his new Barcelona teammates until July 29.
The 21-year-old Brazil striker is scheduled to fly to Barcelona Thursday where he will have four days to settle before starting his pre-season campaign with the Catalan club, reports Xinhua.
He posted a photo on Instagram in which he showed obvious physical exertion during an abdominal workout Wednesday.
According to Globosporte, Barcelona have already tailored a programme for the forward designed to add five kilograms to his 64.5kg frame.
Neymar is not expected to play in Barcelona's friendly against Poland's Lachia Gdansk July 30, which was rescheduled after the announcement of coach Tito Vilanova's resignation due to illness.
His first match for the reigning Spanish champions is likely to be against former club Santos in a friendly at the Camp Nou Aug 2.
The fixture is part of the agreement that brought Neymar to the club in June for 57 million euros.