Alam, who led the team to the World Twenty20 title in England last week, warned that the biggest problem for the tourists will be the hot climate.
"Fitness is very important on the tough and long tour of Sri Lanka," said Alam before heading for Dubai and then Colombo.
The tour comprises three Tests followed by five one-day matches and a Twenty20 international.
The first Test starts in Galle on July 4 but Pakistan open the tour with a three-day match against a Sri Lanka Cricket XI in Colombo from Monday.
"Sri Lanka will be hot and in such a climate your fitness is tested, so we have (put a stress) on fitness, which will play an important role," said the former leg-spinner and Pakistan captain.
He said the series would be interesting as both teams have talent.
"Sri Lanka have quality spinners in (Muttiah) Muralitharan and (Ajantha) Mendis but our batting is good and I hope it will be up to the challenge of playing in the heat and against two world-class spinners," h