ACE announced last week that the attempt to recruit people from the age of 50 had not been successful and that Heyday would concentrate instead on people aged between 65 and 80.
Lishman said his apology focused on the fact that local Age Concern branches had paid for recruitment officers for Heyday. More than 40 Heyday staff have now been made redundant.
He said that there were lessons to be learned, but added: "We have never used the word 'failure'." Heyday aimed for 300,000 members in a year but got only 45,000.
Lishman said that ACE trustees had voted unanimously against a motion from the charity's north-west region that said he and Catherine McLoughlin, the chair of ACE, should be held accountable for Heyday.
"There's no sense in which any individual is more responsible than any other," he said.