Naming Fields - Longer / More Descriptive Names

Which is considered clearer and better for naming?

class SpeedAnimation {
//rate to increment frames at 0 speed
public float baseIncrementRate;
//additional rate to increment frames at, scaled by the speed
public float speedIncrementMultiplier;
//current fractional frame index
public float currentFrameIndex;
//give the upper and lower index bounds to animate between
public int startingIndex;
public int endingIndex;
}

vs.

class SpeedAnimation {
//rate to increment frames at 0 speed
public float base;
//additional rate to increment frames at, scaled by the speed
public float multiplier;
//current fractional frame index
public float index;
//give the upper and lower index bounds to animate between
public int start;
public int end;
}

I've always been really elaborate with my names, because I thought that being more descriptive is more precise and lowers the chance that names might clash with each other, but then I noticed that a lot of my code becomes really lengthy and tiring to read, ie.:

float speed = body.getVelocity().len();
float positionIncrement = (baseIncrementRate + speedIncrementMultiplier * speed) * deltaTime;
currentFrameIndex += positionIncrement;
currentFrameIndex = currentFrameIndex % (startingIndex+endingIndex-1) + startingIndex;