Manager Steve Bruce says his Sunderland side will quickly feel the benefit of their trip to Portugal.
The Black Cats spent 10 days in the Algarve, playing games against Brighton, Hull and Benfica in Albufeira.
They returned to the UK yesterday with a win, a draw and a single defeat under their belts ahead of the final two friendlies.
The side trained twice a day throughout the trip in hot conditions, a process which Bruce says will reap considerable benefits in the long run.
"We've got to be pleased with the overall tour," said Bruce, whose side will now face Leicester at the Walkers Stadium this Saturday.
"It's never about results, it's about fitness levels.
"We've gome some yardage in and put some money in the bank, as the cliche goes.
"The lads have worked really hard in hot conditions and that can only benefit them when they get home."