The 31-year-old Briton failed to progress beyond five quarter-final appearances in 2005, spoiling his record of reaching at least one ATP final in each of the previous eight years, and he dropped out of the top 20 for the first time since 1996.
Henman told reporters in Doha, ahead of Monday's $1 million Qatar Open, that he was determined to make a new beginning and strive hard to be more competitive.
"I have been training for four to five weeks back home," Henman said after a practice session on Sunday. "I am focusing more on staying fit as I want to play in more tournaments."
"I've always enjoyed coming to Doha and playing here," said Henman, who was a finalist here in 1997 and 1999. "The Qatar Open offers a good tune-up before the Australian Open but I am not thinking about winning it."
Henman, who finished the year 36th in the rankings after a rib injury ended his season prematurely, ruled out speculation that he was contemplating quitting the game.
"After 30 there is always such speculation, more so in the media, but I feel I still have a few more years of competitive tennis left in me," he said.
