Noted fitness expert Mackie Shilstone is writing about injuries in the NFL this season and will take a look at the injury report for the New Orleans Saints and their opponent each week.

Have you ever made or heard the comment, "that person has great depth," implying extensive and detailed study or knowledge? The dictionary defines the word "depth" in one category as "the distance from the nearest to the farthest point (where) something happens." In the NFL, depth can be defined as the strength of a team's reserve of substitute players.

Last Sunday in the Saints' victory over the Bucs, depth was one of the keys to the Saints' win. Backup tight end Dave Thomas filled the void left with the ankle injury to Pro Bowl tight end Jimmy Graham. NOLA.com|Times-Picayune columnist Mike Triplett commented in his last Monday column "First and 10," that "once again the Saints proved that their offense is deep and versatile enough to survive the loss of any one playmaker- even someone as critical as Graham."

Noted fitness expert Mackie Shilstone is writing about injuries in the NFL this season and will take a look at the injury report for the New Orleans Saints and their opponent each week.

Several years ago I found myself sitting across from boxing champion Bernard Hopkins on a flight from New Orleans to New York. We had just broken training camp in New Orleans and our team was heading to Atlantic City for an historic fight against then-light heavyweight champion Antonio Tarver. Hopkins was moving up two weight divisions to try and unseat Tarver from his 175-pound title.

I was Hopkins' performance nutrition and conditioning coach. Some of what I have used in preparing all of my 3,000-plus pro athletes for their respective areas of athletic competition has been taken from studying the teachings of the battle strategist Sun Tzu, as told in his 500 B.C. manuscript "The Art of War."

Faster than a speeding bullet, more powerful than a locomotive ... I think you know the rest of the description of Superman. Many fans would attribute this Superman description to that of an NFL player. After all, today's NFL player is bigger, faster, and stronger than ever. In 2006, there were more than 500 players on preseason NFL rosters who weighed more than 300 pounds, so at least part of the equation is accurate.

If I told you that there was a collision involving multiple parties in which some were injured and required medical attention, you might think I was referring to an auto accident. But the impact of tackling in pro football does, in fact, represent an intended accident with each play. And there are more than 100 of these collisions in a typical game.

Think back for a moment and picture a World War II submarine action movie. Remember the scene after the enemy destroyer passes above the submarine with a depth charge run. While the sub's captain is lining up a torpedo shot from the bow torpedo tubes, he calls for damage control to give him an assessment of any and all damage to the submarine. That is, if he survives the attack.

In other words, the battle rages despite damage to the sub or crew. It's about staying alive. While the weekly NFL battle is anything but heroic, it does have some striking parallels to this wartime analogy.