Atlas was raised in his mother's Catholic faith and spent summers in Spring Lake, New Jersey, with his family's friends.

Atlas was involved in a street fight in Stapleton, Staten Island, in which his face was severely slashed with a "007" pocketknife.

He had some amateur fights and won a 135-pound Golden Gloves title but had to turn to work as a trainer due to a back injury.

Atlas enjoyed his biggest success as head trainer to Michael Moorer, whom he guided to the world heavyweight title in 1994.

He drew criticism for what some considered to be overly dramatic speeches in the ring corner, particularly during Moorer's heavyweight title fight with Evander Holyfield, and some felt he did this to draw attention to himself rather than help his fighter.

"[7] Atlas also worked the corners of featherweight world champion Barry McGuigan in one fight and light heavyweight Donny Lalonde.

With Atlas in his corner, Bradley knocked out Rios in the ninth round of their fight, which took place on November 7, 2015, in Las Vegas.

In September 2018 Atlas agreed to train Oleksandr Gvozdyk for upcoming fight with Adonis Stevenson on December 1, 2018 in Montreal for WBC and lineal light heavyweight titles.

On January 25, 2008, Atlas was suspended by ESPN twice, once for threatening a crew member and once (for one week) after confronting the network's boxing program director, Doug Loughrey.

[15] Atlas worked as a boxing commentator for NBC's coverage of the Olympic Games in Sydney (2000), Athens (2004), Beijing (2008),[16] London (2012) and Rio de Janeiro (2016).

[17] In 1989 he was part of the cast and the crew in the film Triumph of the Spirit which portrays the story of Salamo Arouch, a Jewish Greek boxer who survived the Holocaust by boxing (over 200 bouts) for the entertainment of German Nazi officers in Auschwitz Concentration Camp.