I prefer hard water bottles for their versatility. Of course, I drink out of it, but it can also relax tight muscles and soothe sore knees.
Instead of transporting a cumbersome foam roller to events, I use my water bottle instead. Filled with warm water, the therapy is super effective and convenient in any ski lodge.
After the race is over and my bottle is sitting outside all day, it freezes pretty solid. Usually, this isn’t a bad thing though because a frozen water bottle makes for a great ice massage. By the time I finished icing both knees, the water is generally thawed and ready to hydrate.
For winter traveling and athletics, nothing beats having to schlep less gear. That’s why my water bottle is always on hand.