40-yard dash tests more than just speed

40-yard dash is key entry point to the NFL (1:15)

Bill Polian explains the importance of the 40-yard dash at the NFL combine, while Darren Woodson demonstrates proper technique. (1:15)

The 40-yard dash is a moneymaker. Post a great time in Indianapolis? Well, a 4.4 40 buys you a ticket to The Show.

I knew it way back in 2000 when I ran at the combine. Every defensive back does. Same with the wide receivers. Heck, even the big boys on the offensive and defensive lines want to test well. Speed sells in the NFL.

But these young cats running this week in Indianapolis aren't in the perfect environment to light up the track inside Lucas Oil Stadium. Nope. By the time you put your hand in the ground and drop into a sprinter's stance, you're worn down. Days of interviews, medical testing (with doctors and trainers raking on your knees, shoulders, etc.), written exams, the bench test, late-night meetings with scouts, early-morning wake-up calls for drug testing ... man, that beats you up. And you don't run or do any positional drills until the final day at the combine.

But hey, that's exactly what the league wants, right? And I get it. This isn't a pro day on campus where you get to dress in your own locker room and run on your own track. Those things are layups compared to the grind of the combine.

Here in Indianapolis, these pro clubs want to see how you perform in an adverse situation. You should be worn down given the enormity of this event. Your body tightens up, you don't sleep much and all you can think about is that 40-yard dash. I know I did from the minute my plane landed.

But despite all that, teams want to know: Can you showcase your athletic ability when the environment isn't ideal? That's exactly what being an NFL player is all about.

The track has changed since I ran back at the old RCA Dome. That was real turf, the old-school stuff, and it had a little bounce to it. Some of the top guys didn't even bother running the 40. But a guy like me? A late-round defensive back? Yeah, I was going to run. No doubt. I even tried to sneak some track spikes out there until a scout looked down and told me there was no chance I was wearing those shoes. Take them off, son. Nice try.

So I settled for a pair of track flats. Lightweight speed shoes. At least, that's what I told myself while warming up. And then I spent five minutes trying to rig up the oversized, heavyweight combine T-shirt I was issued. It went well with the 1980s Larry Bird-style shorts they handed out. Gross.

The sweet Under Armour gear the guys wear now? The shirts with heart-rate monitors built in or something? Nah, we didn't have that stuff.

Tie up your T-shirt and go. That was it for us. I broke 4.5 -- barely (4.49).

"Your body tightens up, you don't sleep much and all you can think about is that 40-yard dash. I know I did from the minute my plane landed."

The track inside Lucas Oil Stadium now is pretty clean. Honestly, it makes me question any healthy prospect who decides not to run here. It's a fast track. With FieldTurf and prospects wearing cleats, you can get a good start and bust out some serious times. We will see that over the weekend and into Monday when those wide receivers and defensive backs toe the line.

But while most of our focus is on the 40-yard dash, we can't forget about the change-of-direction testing, the vertical jump and the positional drills that expose all of your weaknesses. Tight? Stiff? Inflexible? Then it will show in the short-shuttle and three-cone drills, and when you are asked to open your hips or work laterally in position drills.

The point? You can't hide at the combine. I took a bath in some of those defensive back drills. I really did. That wasn't my gig as a player, and it showed.

That's why I still value the athletic testing at the combine. No, it doesn't tell us whether a prospect can play at a high level in the pros, nor does it show us how tough or physical a guy is. And a 4.4 40 doesn't mean much if a prospect has sloppy technique on his college game film. I'll take a safety with 4.6 speed any day if he can tackle, create range over the top and display the proper angle to finish a play. That's football.

But the combine is just another part of the grading process. And the various tests, culminating with the 40, leave players exhausted. I mean, it felt as if I had just played a game. My hamstrings were locked up, my back was tight. The combine will break down even the toughest guys in this year's draft class. Which is exactly the point.

ESPN.com NFL analyst Matt Bowen played seven seasons as a defensive back in the NFL.