Results seen from filler that is placed in areas of high mobility (e.g. lips) will not last as long as filler placed in more static areas of the face (e.g. cheeks). This is because the muscular activity causes the product to spread out more diffusely over time from its desired location. If you purposely move your face with exercises, the results will certainly be shorter lived.
There aren't any studies or evidence to show that this helps with the longevity for Juvederm.