Felix Baumgartner could have died in one of many ways during his record-breaking skydive from the edge of space on Sunday.

The slightest breeze could have interrupted the daredevil's solo ascent to roughly 39 kilometres above the Earth in a gossamer-like balloon. His pressurized suit could have failed, his blood could have boiled, his chute could have failed to deploy. Even breaking the sound barrier could have had disastrous, unknown effects on Baumgartner's body.

But in the end, said Dr. Greg Wells, CTV's sports analyst and human physiologist, Baumgartner's meticulous training and preparation paid off. The extreme athlete successfully executed his death-defying free fall from 38.6 kilometres, landing safely in New Mexico after reaching a maximum speed of 1,324 kilometres an hour, or Mach 1.24, which is faster than the speed of sound.

"He's jumping from the edge of space, it's an environment that's -68 F, there's literally almost no air molecules,” Wells told Canada AM on Monday. “When you see him step out of the balloon and plummet to Earth there's nothing holding him back, he's accelerating up to 1,300 km/h."

Here are some key of the key physiological challenges Baumgartner, a 43-year-old Austrian, managed to overcome ahead of his supersonic skydive, as broken down by Wells:

Diet: Baumgartner maintained a tightly controlled diet during the lead up to his jump, Wells said. He eliminated any fibre content from the foods he ate, consuming only foods that were easily digestible by his body. By the time he reached jump altitude, his body was effectively empty of food.

"If you go to altitude and there are any kind of gases in your system, they could expand and that would feel extremely uncomfortable," Wells explained.

Breathing: Similar to his dietary restrictions, Baumgartner had to closely control what he breathed in the hours leading up to his jump. For the two hours before his balloon lifted off the ground, Baumgartner breathed nothing but pure oxygen, which essentially "got rid of all the nitrogen from his body, because you can essentially get the bends when you ascend to the heights he was at."

Pressurization: Baumgartner used a special suit to control the pressure within his body as he experienced changes in atmospheric pressure. The suit was designed to provide protection from temperatures ranging from 100 F to -90F, but also to maintain pressure and keep the liquids within his body tissue from turning to gas and expanding. This condition is called embolism, which Wells said is akin to a boiling of the blood.

"At that height, if his skin was exposed, there's so little pressure that the blood and the gases within the blood would boil up just like opening a can of pop, it would boil out and blister or burn the skin," Wells said.

Control: At one point, after Baumgartner had stepped off the platform and begun his free fall, he appeared to lose control and begin to spin wildly. But he quickly managed to regain control and stop the cartwheel-like spin.

"That was really scary because that's the one thing that could go wrong if he spun too quickly and the G-force knocked him out," said Wells, noting that meant Baumgartner wouldn’t be able to deploy his parachute.

"The fact he was able to regain control – and you saw him in perfect control near the end of the jump – was quite an accomplishment."

An estimated 7.3 million viewers watched as Baumgartner became the first person to reach supersonic speed without travelling in an aircraft. The capsule he jumped from had reached an altitude of 39,000 metres above New Mexico, carried by a 55-story helium balloon.

Wells said the jump sets a new standard in the daredevil world, but also for those questioning just how far the human body can be pushed.

"You can imagine the sensation of looking out over the Earth, the sky is absolutely black, you can see the curvature of the Earth, jumping, and then the acceleration, your heart coming up into your throat and then actually executing under pressure, controlling the diet, managing the spins,” Wells told Canada AM on Monday.

“He was communicating with the ground at several key points in time so it was amazing control from an incredible athlete.”