If you like fitness but don’t want to spend money, where can you find such a good thing? Let’s take a look at using Coke bottle waste to make dumbbells. The production method is super simple. Prepare two Coke bottles, cut off the head and bottom respectively, and fix them together with tape; then fill the bottle mouth with sand; finally, combine the two parts through the bottle mouth. One is easy to use. The dumbbell DIY is completed.