Let's look at conditioning for fighting.
If it were true fighting is the best conditioning then the best conditioning for any sport would be playing that sport. But decades of research and experience have conclusively shown that to be false. A large body of published research demonstrates that simply playing/fighting is not the best conditioning. Furthermore countless athletic teams have implemented specific conditioning programs and seen performance improve. Teams with these kinds of conditioning programs normally do better than those without.
When you are familiar with the evidence on the topic there is no doubt that simply playing is not the best conditioning.
Should we conclude that martial arts are the only human physical activity where this rule is broken?
The EvidenceA well-developed and effective program always has three characteristics:
OverloadCardiovascular overload is not common in free sparring for most people. It happens. Of course. But it's not happening much. And not to the degree seen in actual cardio training. If I do several matches during my groups free fencing period I may be quite winded by the end of the last one. But that's not the same as doing intervals.
In interval training I may sprint 100 yards in 20-25 seconds. I am far more winded at that point then I am after 3 minutes of fighting. I have achieved a higher level of overload.
And since I am interval training I do another 100 yard sprint as soon as I get back to the finish line. And I repeat this for several cycles. This is far more intense than just doing some fighting training. Or I'll do 1 minute at 10.5 mph (16.9 kph) on the treadmill. This is alternated with 4 minutes of walking. After 5 blocks like this (only 20 minutes) I am far more winded than 45 minutes of free-fencing with my students.
Some of you are probably quite fatigued by the end of a session of free-fencing. Some of you know people in your group who just don't last as long in free-fencing. If fighting was really working so well for conditioning would this still be happening? If it worked the problem would just go away after a couple of months of training like that.
When we free-fence at my school we fight until I have exhausted all the students. I can keep fighting at this point. I normally feel energized and awake at the end of class.
Besides, do we want fighting to the point of total fatigue to be our norm for training? Sure, training under stress conditions should be done periodically, to acclimate our body and mind. But as we fatigue we lose our ability to implement strategy, tactics and fine motor skills. Should we be regularly training to this level of fatigue? No, because doing so impairs the progress and development of those attributes.
And if you only fight to fatigue sometimes, then you are not doing it often enough to get a meaningful cardiovascular training response. For a good adaptive response it is necessary to train to overload several times per week.
ProgressionProgression is increasing the difficulty variables of training over time. Without it there is no long-term progress. With fighting as our sole conditioning what will you use as progression? You can increase the number and duration of fights. But can you force each fight to be equally intense? Or will you slow down as the number of fights mount up?
Against a canny opponent will you attack with great ferocity to train metabolic power? No. You will fight smarter. And the conditioning stimuli of each fight will depend on the opponent. You can't develop a clear program to stress specific variables.
As I've described previously there are a couple of different attributes to train with conditioning: recovery and power. Achieving progression with these components is easily done by manipulating simple variables like recovery time and duration. Variables that you can control completely. This leads too . . .