EUGENE — Cornering Jim Radcliffe for an interview is like trying to photograph a snow leopard.

EUGENE — Cornering Jim Radcliffe for an interview is like trying to photograph a snow leopard.

Oregon's strength and conditioning coach is a rare species who prefers to roam out of sight while the athletes he trains bask in the spotlight.

Ask anyone inside the program and they will tell you the renowned "Coach Rad" is the heartbeat of Oregon football.

And what a strong heartbeat Radcliffe has.

The 55-year-old is in better shape than many of the freshmen when they arrive on campus.

"He's extremely unique. I think he takes what we're trying to do on the field and structures his program to optimize what we're trying to do," offensive coordinator Scott Frost said. "There isn't always that cooperation between the X's and O's on the football field and in the weight room. Coach Rad gets us in shape, he gets us running well and he gets us faster."

Frost, the former Nebraska quarterback who looks as if he should still be on an NFL roster, added: "I can only hope I look like coach Rad and I'm in as good a shape as him when I'm 10 years younger than he is now."

After the first practice on Tuesday, coach Mark Helfrich said the Ducks are bigger, faster and stronger than they've ever been.

From defensive lineman Arik Armstead to quarterback Marcus Mariota to kicker Matt Wogan, returning players were driven to add muscle to their frames in preparation for a 2014 season that includes home games against Michigan State and Stanford.

Secondary coach John Neal described Radcliffe, who spends the winter and summer working with the players when assistants aren't allowed to be involved in workouts, as the "most trusted" member of Oregon's staff.

"We watch film together," Helfrich said of his relationship with Radcliffe. "And I'll say, 'How can we train this better? How can we break down a change in direction and make a tackle better? How does that now transfer into the weight room? How can we get bigger, stronger, better up front on both sides of the ball?'

"Part of that is recruiting, part of that is coaching, part of that is strength and conditioning. Fitting that together, he's been phenomenal for a long time."

Radcliffe has been getting the most out of Oregon's athletes, whether they're walk-ons, Heisman Trophy candidates or Olympians, for 30 years. The former defensive back received a bachelor's degree in physical education at Pacific University, earned a master's in biomechanics at Oregon and has written books on plyometrics.

When new players arrive in the summer, Radcliffe puts them through "running school." There are stories of unorthodox training sessions, including having linemen push his 1966 Chevy truck up hills around Eugene. Even the way the Ducks stretch before games is must-see viewing at Autzen Stadium.

"I remember when I first got here, I was supposed to be watching practice and learning the system, but I couldn't take my eyes off Rad," said wide receivers coach Matt Lubick, who is entering his second season at Oregon. "I've never seen a guy in that good of shape sprint 40 yards, every play. The way he attacks our stretch, it's contagious with our players. "¦

"The players watch him, and if you've got a guy who's double your age kicking your butt in every conditioning drill, you're going to do whatever it takes to step it up and feed off his energy. He's just unbelievable."

This winter Radcliffe reassigned the weightlifting groups, forcing cliques to disband and players of different ages and position groups to bond.

"I think being in those groups and not being with your friends, you get challenged more," senior defensive end Tony Washington said. "You're kind of working with guys you don't hang out with as much. You see them around, but you don't really know what they're like in the weight room. It's all about pushing each other, and I think that really helped us out this winter."

The burning question for the bulkier Ducks: Will the program, which sprinted its way onto the national map under Chip Kelly, lose a step?

"We won't. We have full faith in coach Rad," Washington said. "He knows what he's doing. He's been doing this longer than we've been alive."

Radcliffe, who declined to be interviewed, has described his job in the past as part art, part science. He has collected data on hundreds of athletes over the years and tailors his ever-evolving program to individual players, positions or teams to improve agility, balance, flexibility, mobility, posture, speed and strength.

"His expertise, knowledge and always staying on the cutting edge has been one of the huge reasons why Oregon is where it's at," Lubick said.

During the season, the Ducks "go hard" on Monday, Tuesday and Wednesday. The physical intensity is backed off for the Thursday practice, but the team ramps everything back up on "Fast Friday" instead of going through the motions of a typical walk-through like many programs. The recovery process begins immediately with postgame ice baths on Saturday and more treatment on Sunday.

Radcliffe doesn't ask his pupils to do anything he can't do with them. Players say he does more lifting, running and stretching than anyone.

"It's one of a kind. There are not a lot of programs that have a guy like coach Rad," wide receiver Bralon Addison said. "A pretty old guy, but you would never know he's so old. He runs around with us at practice all day. In the winter he's running around with us. Every workout we do, he's doing it with us. You don't find that at a lot of places. He's awesome.

"In my opinion, he's the best in the business. I think that helps us, to see a motivated guy like that."

Washington coach Chris Petersen, a former Oregon assistant, said hiring an elite strength and conditioning coach was No. 1 on his to-do list after joining the Pac-12. He was able to bring Tim Socha with him from Boise State.

"They're everything. Finally people are starting to figure out how valuable they are. They're staring to get paid better," Petersen told Sports Illustrated. "I mean, they probably spend, and I don't even think it's a probably, they do spend more time than myself or the assistants with these kids. That was my first hire, and probably my most important."

Radcliffe has worked for Rich Brooks, Mike Bellotti, Kelly and now Helfrich. Reporters with a trained eye can spot him after practices sprinting from the field into his laboratories at the Hatfield-Dowlin Complex or Casanova Center as if he were being chased.

"We're really fortunate to have a guy like him. He's completely dedicated, he's tireless and he's a really good person. That's a lot to say about a guy. That's a nice résumé," Neal said. "Jimmy could be the strength coach for any program at any level, but he chooses to stay at Oregon, which is really cool."