Bryson DeChambeau has been the talk of the PGA Tour since adding 20lbs of muscle during the coronavirus shutdown and becoming one of the longest hitters on the circuit – and the architect behind the 26-year-old American’s retooled phsyique understands the chatter might not exclusively be complimentary. Greg Roskopf, a biomechanics specialist who works with the NFL’s Denver Broncos, is keenly aware that outsiders might think DeChambeau’s abrupt muscle gain is a product of chemical enhancement, but insisted what may appear to outsiders like an overnight transformation was anything but. “Because we’ve had [a three-year] foundation, you’re seeing the end result of it happened quick,” Roskopf told ESPN on the eve of this week’s PGA Championship at TPC Harding Park. “But the two years of preparation to get him to the point where he could make those changes is really why he’s been able to make those changes as fast as he’s been able to make it. “But under normal circumstances, you’d say the only way somebody could make those changes is by taking steroids. And I can guarantee you, that’s not been part of his process and not even a thought in his head. It’s just been part of the evolution of him being involved in this program and being able to tolerate the forces that his body’s been able to tolerate. And those changes in strength have been amazing, but it’s all natural from this end of it.” DeChambeau, the world No 7, has increased the distance on his tee shots by more than 20 yards on average since adding 20lbs of muscle under Roskopf’s watch. He captured the eighth win of his career at last month’s Rocket Mortgage Classic and is hotly tipped to improve on his career-best major finish of a tie for 15th. The Californian has attributed his dramatic overhaul from 190lbs to a muscle-bound 240lbs to a diet of about 3,500 calories per day including an array of protein shakes, but Roskopf told ESPN that figure is likely undershooting it – an increasingly foreign experience for DeChambeau these days. “I think that’s very low,” Roskopf said. “It might be close to double that, five to 6,000. I’ve done measurements of caloric intake and dietary analysis. And I’ve seen with athletes, what they are taking in and I’d say he’d be up to five to to 6,000 calories a day with all the protein shakes he’s taken in and the food he is eating. He’s got a lot of calories going into his body, and in a low level, 3,000 to 3,500 wouldn’t allow him to gain the type of mass that he’s gained over this short period of time.” DeChambeau made headlines last week when he revealed his intent to “live to 130 or 140 [years old]” in an interview with GQ magazine. “I really think that’s possible now with today’s technology,” he said. “I think somebody’s going to do it in the next 30 or 40 years.” He added: “I didn’t have a lot of resources when I was young. I couldn’t go down all these roads with these questions that I asked at an early age. But now that I’ve been able to have some success, I’ve kinda gotten deep into most of these things and only taken what has added value to me.”