In his book "Run to Daylight," Vince Lombardi describes a Saturday practice in the 1962 season that sounds an awful lot like the typical Saturday practice in today's NFL.
His Green Bay Packers, working on what's now Lambeau Field the day before the game, warmed up with calisthenics. They practiced driving off the snap, did a seven-on-seven passing drill, and then walked through formations and plays.
Lombardi didn't invent the Saturday jog-through, and the custom very well could date as far back as the late 1920s, when Curly Lambeau pioneered daily practices in the NFL.
So last year, Philadelphia Eagles coach Chip Kelly proved to be a true radical when he flip-flopped his schedule by conducting jog-throughs Friday and regular-speed practices Saturday. When coach Mike McCarthy did the same this year, the Packers became only the second NFL team to defy conventional wisdom in an area of team management — the training schedule — that coaches consider paramount to success.
"Turns out we pretty unanimously have enjoyed it," said Matt Flynn, the Packers' backup quarterback. "But it's definitely different. It goes against everything that everybody's always done. I like that people upstairs have thought outside the box and are doing things they know are going to help our bodies."
Kelly and McCarthy made the change because of their trust in sports science, and though it's too early to conclude whether it has improved performance, early signs are promising.
For the Eagles, it's hard to separate the impact of Kelly's in-season practice schedule from everything else he's brought to the team, including his turbo-speed offensive system, play-calling acumen and possible upgrades in personnel. But his team is winning. The Eagles were 4-12 in 2012, the year before he took over, and are 17-8 (10-6 in '13, 7-2 this year) in his 1½ seasons.
McCarthy's Packers are 6-3 this season, and their injuries are way down from the last few years.
One of the main theories behind the flip-flop is that practicing nearly full speed Saturday primes players' central nervous systems for game day, whereas jog-throughs don't. The key is that the Saturday practice has to be relatively short.
Dr. Inigo Mujika, a sports scientist at the University of the Basque Country in Spain, is one of the world's leading authorities on training tapering for optimal performance. He said in an email he couldn't offer a clear answer on the Packers' and Eagles' new schedule without knowing the details and goals of the practice week. But he thinks the schedule makes sense because players get Friday to recover from hard work Wednesday and Thursday, and then are fresh and sharp for a quality practice the day before the game.
"But only," Mujika said, "if the Saturday session is not so demanding that it induces excessive neuromuscular fatigue and provokes too much of a depletion in the muscles' glycogen stores (the main fuel for performance during the game), as 24 hours would not be long enough to fully recover if that were the case."
Practicing briskly the day before the game is new to football, but not to sports in general. Olympic sports have trained with that philosophy for years, and Kelly reportedly consulted experts in track and field before he first made the change while at the University of Oregon.
"If the athlete is already rested/primed for competition, taking a day off or (going) very light often leaves them feeling flat," said Dr. Robert Chapman, associate director for sports science and medicine for USA Track and Field, in an email. "Most will do something short (the day before the race), but approaching competition intensity."
The Packers' and Eagles' practice schedules are similar because of the flip-flop, but they're not the same.
For the rest of the NFL, players on Monday walk through assignment corrections from the previous day's game and do some kind of active-recovery workout to alleviate soreness. Tuesday is the players' day off. Practices Wednesday and Thursday are on the longish side, perhaps two hours, and practice Friday is a little shorter, 1½ hours or so. Then Saturday is a walk- or jog-through, usually an hour or less, to rehearse formations, audibles and substitutions.
Kelly, on the other hand, gives his players Monday off and practices them four days. On Tuesday, according to a story in the Philadelphia Inquirer in September, they practice for about 1½ hours. They practice Wednesday and Thursday, like everyone else in the league. Friday, their only on-field work is a long walk-through. Then Saturday they conduct a short practice.
McCarthy, on the other hand, kept the old Monday schedule and the three-practice work week. Like the rest of the league, his players are off Tuesday, then have their heavy practices Wednesday and Thursday. On Friday their only on-field work is a walk-through, plus they have mandatory recovery activities. And Saturday, they practice for at most 70 minutes.
"You get your work in for two days and then you get Friday off to get little massages and all of that stuff," said Julius Peppers, the Packers' 34-year-old outside linebacker. "It's kind of like (throwing you) a bone. You practice for two days, then you're off, so I think you get a better quality of work."
Friday's mandatory recovery activities are set up around the team's facilities after morning meetings and lunch. Players generally are required to do at least two, though some do more.
The choices include deep-tissue and trigger-point massage; Graston Technique, which uses metal instruments to break up scar tissue; chiropractic treatment; hot and cold tub; foam rollers; and NormaTec compression boots, which are like giant blood-pressure cuffs worn from toe to hip that provide pulsating pressure up and down the leg like a massage.
"It definitely helps," said Sean Richardson, a core special teams player and backup safety, of the Friday recovery. "Most guys already take care of their bodies anyway. It's just a mandatory thing, make sure everybody's doing it, and then do less stuff outside the stadium with their own massage therapist."
On Saturday, the short practice includes no contact and is conducted at a brisk pace though not quite full speed.
"You don't want anybody on the ground, you don't want to take the chance of getting a guy injured the day before the game," Capers said. "It's more timing and the mental preparation, so you go out and it's not that physically taxing on them. It's probably a little less (intensity) than what you would have had on a Friday practice (with the old schedule)."
Said Flynn: "As quarterbacks, we throw the ball hard and loosen up the arm and grease it up a little bit. I know the receivers, they run fast and try to get a good sweat going. But I don't think anybody's overdoing it. We aren't overthrowing it, receivers aren't running to where they're getting tired. It's all about taking that day off Friday and coming out Saturday and revving it up just a little bit."
The change in practice schedule is about performance Sunday, but it also is part of McCarthy's efforts to reduce injuries after several bad years on that front. One season is too small a sample from which to draw many conclusions, but he has to be happy with the results heading into Week 11.
In Week 11 last year, the Packers had nine players on IR and 11 more on their injury report. They played without eight starters and rotational players that week. The year before, they had 16 players on the injury report and two more on IR. On game day, only one of their seven inactives was healthy, and they played without seven starters and key rotational players.
This year is a different story. They have four players on this week's injury report, only two of whom won't play: backup tight end Brandon Bostick, and backup outside linebacker Jayrone Elliott. And though the Packers have eight players on IR, only one (B.J. Raji) is a starter, and there's a good chance none of the others would be more than special teams players even if healthy.
Neither Kelly nor McCarthy say much publicly about the specifics of their training systems, because it's one place teams think they can gain an advantage. But NFL teams catch on quickly. The guess here is that within a few years, many and perhaps even most coaches will flip-flop Fridays and Saturdays.
"It's going to take proof to be able to change guys, and it's going to take open minds," Flynn said. "This is pretty new. I wasn't aware that Philly did it last year, but if they did it's still new compared to what everyone's always been doing. So the results still remain to be seen."
— firstname.lastname@example.org and follow him on Twitter @PeteDougherty