These SMART goals do make sense, you just might need more time to see these results. For example to increase hair growth and volume is one thing but having a thick healthy ponytail is another. An increase of density definitely depends on internal practices mostly as what you eat, how you exercise etc. are super important in determining how healthy and dense your hair grows out of your head. These sort of internal changes take about 3 months to show in your hair. Therefore in 3 months of incorporating the new practices you will learn, you should start to see results. However, these results could be in the form of new baby hairs which would probably help boost your density and volume at the scalp, though it would take a while for them to reach ponytail length! So it would take longer for your ponytail to get thicker!