Precisely. Sadly scientists (like other humans) are all too willing to step aside and let the press do whatever it pleases to maximize their publicity. The 'last psychiatrist' had a recent posting relating this to how certain scientific facts appear to later become unreproducible. The truth being that the original research was merely misrepresented, usually via a motivated lack of skepticism and disregard of nuance.

Before human civilization I suspect that we walked much more than a couple miles per day. Caging the rats is comparable to the reduction in daily movement due to cars, availability of food, etc.

Setting the baseline to non-urban rats would tell us more about the health of prehistoric humans than modern ones.

For their study to be valid in proving that exercise prolongs 'youthfulness' it requires that they be meeting the species normal exercise limits before expanding on them, otherwise they're actually performing a study on how sedentary lifestyles reduce youthfulness.

This is a scientific study that isn't being accurate about what it's even studying, which makes me instantly dubious of any of its results.

That is assuming the definition for exercise is any level of activity above the standard and expected activity level of a species.

Put into context, your reasoning implies that a rat running around all day looking for food is not exercise.

Their control is sedentary rats because they hope to extend the results to humans, and humans are sedentary. If we were all hunter gatherers, you would have a point.

Then their control isn't the control but is the experiment group. If you're exercising under the species baseline norm then you're studying how sedateness decreases youthfulness, not how exercise prolongs it.

Humans were hunter gatherers, their level of exercise would be our evolutionary norm, IE the obvious control group. Exercise above or below our evolutionary norm would give us information as to how best increase longevity.

It's a commonly accepted 'fact' that our exercise below this evolutionary norm is detrimental to our health. Exercise above and beyond our social norm is obviously going to beneficial to our health and weight as it is equivalent to moving us towards our hunter gatherer ancestors, but this is only normalizing a wrong we already know about.