Yet again I gave squats a go to see what effect they'd have on my body. For a couple of months I did free squats; one rep to three quarters and one rep full counting as one repetition. I'd do 312 of these in a countdown workout. On the plus side, it is a good way to build the thighs; especially the lower thigh. However, for me, whether on the toes, flat-footed, half or with weight, the tendency is for my stomach to push out. It is just the way my natural body leverages work.
Now for some, this is not the case. Once again, it all depends on your limb lengths and how forward your spine sits in relationship to your hips. Hip width also plays a part. So anyway, for what I want, sprints are more practical in terms of over all fitness and self-defense. So now that we've got the warmer months and sunshine; it is back to incline sprints.
By the way, sprinting is a good thing to practice for self-defense. You may have to run away from a predator, or perhaps even chase one down. Imagine a child or grandchild being kidnapped. You see the practicality of sprinting in that application?
Mike - you might want to try the 1 and 1/2 rep squats I was using. It creates a lot of tension on the thighs and doesn't require weight, although you could very well use a light barbell with them. This was a technique from some of those 1940's and 1950's era bodybuilders who didn't have a lot of equipqment and had to adapt.