If you've ever had a hair tie break on you while as you put your hair in a ponytail, you'll know it's a terrible feeling. Because this always happens to me (especially seconds before my workout starts), I always stock up on hair ties. The Scunci Thick Hair Black Elastics ($13 for two packs) are my go-tos, and I always keep two on my wrist and one around my water bottle just in case.