TUSCALOOSA, Ala. -- Alabama football players opened preseason camp with five NCAA-mandated "acclimation" practices to get the fundamentals down.

The heavy lifting began Tuesday.

The first of three two-a-day practice dates began a stretch of playbook-cramming that coach Nick Saban knows can be a lot for the young players to handle.

"It's kind of the whole theory of learning," Saban said after the two-hour practice that started at 9:30 a.m. CDT. "You throw it on the wall and see what sticks. Pick up what doesn't stick and throw it up there again and see if it sticks the next time."

In a rare move, the players wore full pads Tuesday morning for the second straight practice. They wore shorts with shoulder pads and helmets for the 7:30 p.m. session.

There will be just one workout today at 2:30 p.m., followed by another two-practice day Thursday. The final two-a-day will come Monday following the first off day since camp started.

Each day is segmented into three blocks of time (morning, afternoon, night). When there is one practice scheduled for the afternoon, there are morning meetings and weightlifting and night meetings that typically include a speaker. Rogers Redding, the SEC director of officiating, spoke to the team Monday night about rules changes.

When a two-a-day is scheduled, the morning and night blocks are designated for practice with meetings in the afternoon.

Players eat two meals and have two opportunities to hydrate between each practice.

"It has cut down enormously on injuries, IVs, heat problems," Saban said. "We still have a few, but there is a lot of statistical information with the medical staff here that supports the way we go about doing things. We end up having more guys practice more days than most because of that."

Injuries were exceptionally rare for the Crimson Tide in 2008 as less than a handful of starts were lost to physical problems.

A second cooling tent was added to the Thomas-Drew Practice Fields to give players additional opportunities to keep body temperatures from rising into dangerous territories.

Besides giving players' bodies an opportunity to rest, the team meetings help reinforce the teaching done on the practice fields. That means plenty of video work.

Ideally, Saban said, the teaching from the film room carries over to individual drills in practice and will come together when the full unit gets together.

Player leadership is imperative in helping newcomers learn the system, Saban said. Veterans help them through the basics and terminology, and with the smart group of leaders currently in the program, Saban said that process is expedited.

He cited Rolando McClain, Mike Johnson and Julio Jones among those with experience who have worked with the new guys. But everyone learns at a different pace, which can test Saban's patience.

"It's probably good to not yell at them, and it's probably not good to get on those guys," he said. "You know, hey, I pray every Sunday in church that I don't get angry and I don't want to yell at any of the players, but you guys have been around long enough to see my practices and you know that doesn't always happen. So I've got my stuff I need to work on, too. But it does get their attention."