He notes in the video that he was already going to the gym three times a week before this challenge, and that the Murph isn't for novices. "If I were a fitness newb, I'd never even think about going through this challenge," he says. "Even having extensive gym experience, I still consulted with my doctor to make sure that my body could endure this ordeal."

The Murph consists of:

  • 1-mile run
  • 100 pullups
  • 200 pushups
  • 300 air squats
  • Another 1-mile run

Some sound advice which he took on board before starting the challenge included not attempting the Murph on an empty stomach (a meal a few hours before your workout will provide much-needed fuel), and not to try to sprint the first mile: "It's your warmup, so don't waste your energy on it."

He broke the total of 600 reps into 20 sets of 5 pullups and 10 pushups and 15 squats each. (He also forwent the traditional 20-pound vest that CrossFit athletes usually wear during the Murph.)

Day 1 was exhausting, which was to be expected. "Somewhere along the way I started thinking maybe I should have scaled the workout back to a lighter version, or half-Murph," he says. "When I was done, I barely had the energy left to take a shower and get to work."

He also found that his muscles were incredibly sore on Day 2, because he forgot about one very important thing: stretching. "Even though every muscle on my body was on fire and screamed for rest, I still felt motivated to keep going."

By the end of the first week, though, he had already fallen into his new routine. "I still felt unbearably exhausted after each session. This workout is grueling, so it simply won't be any other way....But later, this tiredness turned into a boost of energy that made my day super productive. I even got used to getting up 2 hours earlier so I could do the Murph before work."

He kept going, even through a short bout of food poisoning, and by the midway point, he started to notice visible changes in his body: the shirt he usually wore for work felt tighter as the muscles in his back had grown.

"The last workout was the most satisfying one I've ever had," he says of Day 30. "The pain and tiredness didn't even bother me."

He gained around 4 pounds (1.8 kilos) of muscle, and said that he felt drastically stronger. "I've never been in better shape," he says. "But the most important changes were in my mind... I surprised myself with my own dedication and persistence."