NAPA, Calif. — Rashad Jennings takes every precaution he can to keep his body in top shape necessary for an NFL running back.
He eats a gluten-free diet and sticks to organic foods. He stretches every night and has a regular routine of pilates, acupuncture, yoga and massage.
And when Jennings' long days of training camp are over instead of settling into a soft bed, he climbs into a hyperbaric oxygen chamber to sleep.
Jennings bought the oxygen chamber as a rookie instead of splurging for a car, thinking it would help keep him fresh and prolong his career.
He admits it "freaks" some people out at first and the loud noise forced him into a single room in what he calls the "dungeon" of the team hotel in training camp.
But Jennings is working on getting some converts, saying he has at least six teammates waiting to try out the chamber next week to see how they like it.
"It's not an end all be all," Jennings said. "It's not like this is the biggest healer in the world type of thing, but it does heal you on a certain level. It speeds up the process. I love to practice and I love to stay on the field. It keeps you healthy. Playing this game is important to me. The way I eat and take care of my body is pretty important."
The Oakland Raiders are counting on a healthy Jennings this season as the backup to Darren McFadden, who has never made it through an NFL season without an injury.
Playing the role of a backup to a big-play back is something Jennings has plenty experience doing, having served in that role behind Maurice Jones-Drew in Jacksonville to start his career.
"I tell people all the time there aren't any backups in this league," Jennings said. "The backups are at home. You got to prepare as the starter, you are the starter.
"It's too late to prepare when the opportunity presents itself. I'm a piece of a puzzle. When I'm called upon I have to make sure I'm making my statement."
Jennings did a good job of that in the preseason opener when he ran nine times for 39 yards.
He got loose for a 16-yard run on a read-option play with quarterback Terrelle Pryor and showed the ability to grind for tough yards in short yardage the Raiders are looking for in McFadden's backup.
Jennings is working his way back from two disappointing seasons in Jacksonville.
After averaging more than 5 yards a carry in each of his first two seasons, Jennings missed all of 2011 with a knee injury.
He then struggled mightily last season, averaging 2.8 yards per carry — becoming the 10th back to average under 3 yards a run with at least 100 carries since 2000.
"It was a lot of things, looking at film, I could've done better, but it's all in the past whatever happened, it is in the past," he said. "It's a fresh start as a Raider and that's what I'm out here to capitalize on."
Jennings entered camp in a competition with fifth-round pick Latavius Murray to be McFadden's backup and seems in position to get that job because of his experience and reliability.
Murray showed some good signs in the preseason opener as well with eight carries for 29 yards but has also missed time throughout camp with injuries to the dismay of coach Dennis Allen.
"Being available and being accountable are two things that we have to make sure we're able to be," Allen said.
NOTES: LT Jared Veldheer had a second MRI on his injured triceps and missed practice. ... LB Nick Roach left practice with an undisclosed injury and DE Lamarr Houston returned to the field.
AP NFL website: http://www.pro32.ap.org/poll