It is well established on the historical evidence that—however you wish to explain it—the followers of Jesus had experiences after his death that completely convinced them that he had returned from the grave.  Among the different naturalistic hypotheses which attempt to account for this is the Apparent Death Hypothesis or, “Swoon Theory.” This proposes that Jesus did not really die on the Cross but only fainted and later revived in the cool of the tomb.
On superficial inspection the Swoon Theory seems plausible enough. We often hear stories in the news about people being pronounced dead only to wake up in the morgue or, in some cases, during their own funeral.  However, today the Swoon Theory finds virtually no support among even skeptical New Testament historians; and in what follows, I shall outline the three main reasons for this.
The Swoon Theory is massively disconfirmed by our knowledge of Roman execution methods and military culture. As the historian N. T. Wright notes, “The Romans were very, very good at killing people. They specialised in it.” One reason for this was that the authorities provided soldiers with a powerful incentive to carry out their orders successfully: Any soldier who let a prisoner escape would forfeit his own life in their place—sometimes by being buried up to the neck and burned to death under a fire fuelled by his own clothes. The rule applied if the escapee was an ordinary prisoner of war and applied, a fortiori, if he had been charged, like Jesus, with insurrection against the Roman Empire. Roman soldiers were also prohibited from leaving the scene of a crucifixion until death had occurred and it is inconceivable that the soldiers tasked with executing Jesus would have allowed him to be carried off unless they were certain he was dead.
The Swoon Theory is also massively disconfirmed by our knowledge of crucifixion pathology. Victims of Roman crucifixion were typically scourged until their arteries, muscles and intestines had been laid bare. The Gospels report that Jesus was scourged and that after his scourging he was too weak to carry this Cross to Golgotha—a detail which medical authorities (Edwards, Gabel and Hosmer, 1986) suggest is consistent with hypovolemic shock. Once impaled upon the cross, the victim faced an excruciating physical dilemma: To yield to gravity and slump down, whereupon the weight of his body would constrict the intercostal muscles surrounding his lungs and cause asphyxiation and unconsciousness within around twelve minutes; or to push up against gravity to maintain consciousness but at the cost of supporting his entire body weight on pierced feet. As the historian Gary Habermas observes, it would have been a very simple matter for a centurion practiced in crucifixion to determine that Jesus was dead: He would only have to observe that Jesus has ceased to haul himself up heaving for breath and had remained slumped on the cross for around half an hour. And the spear in the side, recorded in John 19:34, provides additional proof of mortality: The fluid which gushed forth is consistent with a rupture of the pericardium—the sac which surrounds the heart.
And finally: The swoon theory lacks explanatory power to the point of total incoherence when its proponents attempt to account for the origin of the transformative belief among the disciples that God had raised Jesus from the dead. It is prohibitively improbable that the moribund survivor of a botched execution somehow extricated himself from his burial shroud, pushed back the heavy bolder at the entrance of the tomb, overpowered the guard and limped back to his followers—who all immediately fell at his feet in frightened awe and proclaimed him the risen Lord and luminous conqueror of death. As early as 1879, German critic David Strauss put paid to the swoon theory for all time by pointing out that a half-dead Jesus would have inspired little more in the disciples than a wish to provide medical care. According to Habermas, Albert Schweitzer, in his classic volume surveying historical studies of Jesus, “lists no convinced proponents of the swoon theory after Strauss’s critique.”
Skeptics attempting to provide a naturalistic explanation for the post mortem appearances of Jesus would do well to look elsewhere. The Swoon Theory is dead and buried and unlikely to revive.
 “Historians,” writes Bart Ehrman, “have no difficulty whatsoever speaking about the belief in Jesus’ Resurrection. For it is a historical fact that some of Jesus’ followers came to believe that he had been raised from the dead soon after his execution.” Ehrman goes on to suggest a historian, qua historian, cannot adjudicate on whether a miracle occurred. And so Ehrman places the Resurrection hypothesis in historical quarantine.
 For example: A bishop in Lesbos by the name of Nicephorus Glycas was declared dead on March 3, 1896. In accordance with tradition, his body was put on display in the Methymni church. But on the second night of “the exposition of the corpse” Glycas reportedly sat up and demanded to know what he was doing there.