Ronald Post, 53, was sentenced to death for the 1983 murder of Helen Grace Vantz, a hotel clerk in Ohio.
Post, who weighs more than 480 pounds, moved the Federal court through his attorneys on Friday seeking a delay in execution claiming that his current physical condition might lead to a "torturous and lingering death," as reported by AP.
Post has said in court filings that the executioners will most likely face several problems due to his weight, vein access, scar tissues and it could result in inhumane suffering to him. He also argued that he might not fit on the execution gurney.
"Indeed, given his unique physical and medical condition there is a substantial risk that any attempt to execute him will result in serious physical and psychological pain to him, as well as an execution involving a torturous and lingering death," the filing said, according to the AP report.
Post is scheduled to be executed on Jan. 16 with lethal injection that is normally injected through veins in the arms.
According to the court filings, Post said that he did attempt to bring down his weight working out on the prison's exercise bike, but it gave away under the load. Moreover, he is not encouraged to walk as he risks falling and has severe knee and back problems which prevent him from exercising.
Issues of excess weight coming in the way of executions have cropped up in the past too. Condemned double-killer Richard Cooey had filed a similar appeal to stop his conviction in 2008, stating that his weight would make it difficult for the executioners to find a vein in which to inject the lethal concoction.
However, the court had rejected Cooey's appeal, who weighed 267 pounds then, and he was executed on Oct. 14, 2008.
However, a convict sentenced to death by hanging in Washington state got reprieve from execution after the court accepted his argument that he was too obese to be hanged.
Post's appeal has not been welcomed by the victim's son, who told Morning Journal newspaper that his punishment was long overdue.
"Some have said that since it's been so long just let [Post] stay in prison for the remainder of his natural life. No!" William Vantz wrote.
"We all have recourse to the law and it's time he paid his debt to society. It's way overdue!" he added.