Mike MacIntyre
Mike MacIntyre (Associated Press file)

BOULDER — It's difficult to know what was tougher for Colorado's defensive line: going up the hill or giving up Cosmo's Pizza on the Hill.

The hill is a cement path that leads upward at about a 20 percent grade from Boulder Creek near the practice fields to the Dal Ward Center. Cosmo's is the campus pizzeria where the late-night hours are as fattening as the cheese is yummy.

The line, however, is conquering both. The group is nearing a goal first-year coach Mike MacIntyre set almost the first time he laid eyes on the big guys.

Lose a collective 100 pounds. Or else.

When fall camp starts Tuesday at 3:50 p.m., the line will be about 80 percent home. They have until the Sept. 1 opener against Colorado State to drop the other 20 pounds.

"It's very encouraging," MacIntyre said. "That shows you they're buying in."

It's not the entire defensive line, mind you. It's six players. When Colorado hired MacIntyre and he turned on game film from the 1-11 season, problems were obvious beyond the ugly stat sheet.

The Buffaloes' defense finished 119th out of 120 teams in yards allowed per rush (5.9), 115th in rush defense (226.0 yards per game) and 117th in total defense (488.5 ypg).

"They could play, like, two plays hard and the rest they're just getting through the play," MacIntyre said. "(In) today's football, you don't have time to huddle up anymore. You can't do that."

Dave Forman, the strength-and-conditioning coach MacIntyre brought with him from San Jose State, held team conditioning drills four days a week for eight weeks in June and July. Mondays and Fridays were the Longs Peaks of conditioning.

Sometimes the Buffs ran the hill 20 times in a 20-minute period. Other times they did 300-yard shuttle runs in which they ran 25 yards and back seemingly forever.

"It changes every day," Forman said. "There was very little straight-ahead stuff. When you start talking about the big bodies involved and how much force it takes to stop and then start again, you're adding to the load to what they're actually doing."

When the line's conditioning began to improve, Forman had them wear a 20-pound weight vest to simulate helmet and pads. On July 26, they all passed the team conditioning test.

"It was hard, but Coach Forman and the coaching staff did a good job of pushing us and just getting ourselves better," sophomore tackle Josh Tupou said.

Some of the transformations have been striking. Tupou weighed 335 pounds in January. Now he's at 312. Senior tackle Nate Bonsu has gone from 314 pounds in the spring of 2012 to 285 pounds. End Kirk Poston has vastly improved his flexibility.

"We started in the Big 12, and when it was the Big 12 styles weren't that much different," Bonsu said. "You had offenses like Texas, but a lot of people still tried to run the ball. But in the Pac-12, almost every offense is running some kind of spread. They're running 60, 70, almost 80 plays.

"So being in the best shape you can be as a defensive player just makes everything better."

If any player doesn't meet his target weight by the CSU game, he will get acquainted with a certain treadmill and a fat-burning run. But as camp opens, they're already ahead of last spring.

"I have some good hope for them," MacIntyre said. "We'll definitely be better."

Jhenderson@denverpost.com or twitter.com/ johnhendersondp