shinwa,
Running laps is the WORST kind of conditioning to do for fighting… LSD-- long slow distance, is the bane of fighters. You have to do explosive, interval type stuff… 3 minutes on, one minute off… 30 sec all out, 30 sec off. That kind of thing. The days of miles and miles of roadwork is pretty much over.
That said, I think I finally figured out what I’m thinking of.
What seperates athletes from others is not just heart, or work ethic, but kinesthetic awareness. Kinesthetic awareness is that blend of power, timing, flow, coordination, etc. that all of us train for. Kinesthetic awareness is what allows the boxer to hit his target, the gymnast to execute flips, the dancer to move with grace and power.
Kinesthetic awareness is innate, but I’ll theorize this: it can be trained to a higher level through something I’ll kinesthetic conditioning.
Kinesthetic conditioning, to be optimal, must be functional:
It must involve multiple muscle groups.
It must involve timing.
It must involve coordination.
It must challenge the aerobic system.
It must challenge the anaerobic system.
It must challenge the neuromuscular system.
Different activities obviously have different effects… Long, slow distance running certainly improves your aerobic system for long slow distance, but does little to challenge your timing, coordination, or anaerobic system. Olympic weightlifting obviously challenges everything but your aerobic system. Golf makes you into a fat *****. 
People with a high level of Kinesthetic awareness, whether brought about by genetics or training, are potentially dangerous opponents, regardless of “fighting skill level,” because they are so aware of how their body is moving or not moving in relation to their opponent. IE, a kinesthetically aware person, may not know how to throw a great punch or to block properly, but they will probably be in tune enough with the situation to have the right timing to make things difficult, perhaps dangerous. It doesn’t take a genius to figure out that if you step in while somebody tries to kick you, you can take the power out of the kick and grab the leg.
They won’t think of it in those terms, because they aren’t fighters or MA types, but they’ll be doing it anyway, by intuition. They won’t be NEARLY as good as somebody who trains for self-defense, but they will be more dangerous than most, never-the-less.
A college linebacker, Juoko Ahola, an Olympic Weightlifter… all are dangerous opponents because of their kinesthetic awareness.
Skill without kinesthetic awareness is quite possible. How many of you have ever met that dedicated guy who can do ALL the moves in the air, can explain every little detail, can hit the pads with alarming force, knows exactly what to do and why… and has trouble executing on a resisting opponent? They have rotten kinesthetic awareness, for whatever reason. This person, despite their skill level is NOT nearly so dangerous an opponent as somebody who is very kinesthetically aware.
This is what I meant by conditioning: Kinesthetic Awareness. And I will take Kinesthetic Awareness over skill any day of the week.
Of course, by training MA’s you train both fighting skills and your kinesthetic awareness, putting you one up on the rigorous athlete 