I know this isn't really a physics-focused question, but this is still the best science forum that I know of.
http://en.wikipedia.org/wiki/SenseHuman beings have a multitude of senses. In addition to the traditionally recognized five senses of sight (ophthalmoception), hearing (audioception), taste (gustaoception), smell (olfacoception or olfacception), and touch (tactioception), other senses include temperature (thermoception), kinesthetic sense (proprioception), pain (nociception), balance (equilibrioception) and acceleration (kinesthesioception). What constitutes a sense is a matter of some debate, leading to difficulties in defining what exactly a sense is.
I guess I was thinking as a guy who runs for exercise, running for half an hour at a time. I am very aware of such things during a run.Its BS to cite "heating up", and "breathing" as an indicator of how fast you are running. You can run for 3 meters and you can hold your breath doing it.
People know their own bodies, but are taught incorrectly in school that there are 5 senses and then don't think about the issue (but you are, which is why you are asking the question!). Well, there are way more than 5 senses and you use other senses besides just the 5 commonly cited ones in this case.
Anaerobic running (sprinting) is a special instance. Yes, you can run in this fashion for a short distance, but if you wish to run any real distance, you must rely on rely on your senses to let you know what level of exertion you're experiencing, and that is not BS. As a former state-level Cross-Country runner, I can guarantee you that you need a lot more than BS to to gauge your performance during a race and avoid burn-out while turning in your best possible performance. Once I was on-pace (and that might be different for every race), I used to synch my pulse and breathing to my stride to get my best output, but that optimization could not achieved without some reliable expectation of the exertion that would be required. If I hadn't run a particular course before, I could only hope that our team bus got to the venue early enough to allow a brisk walk-through. That was good for a warm-up, and good for a mental tune-up regarding the demands of the course.Its BS to cite "heating up", and "breathing" as an indicator of how fast you are running. You can run for 3 meters and you can hold your breath doing it.
The biggest indicator is from the motion of your legs: the faster you take one step the faster you are running. You know when you take a step because you can feel your legs and you know where your feet are at, its called coordination.