Yes they are: shown in the below images in two different designs.
Gym sacks are inexpensive, costing in the region of £10-£20, which is due to the simplicity of the item: a single piece of material that is enclosed with dual draw cords. Gym sacks are minimalist: typically featuring just one compartment - although some feature an extra pocket on the front - that is a single piece of fabric enclosed with stitching on the bottom and side, and a draw cord/string on the tope to enclose and open the sack. Adidas gym sacks are usually made from polyester: a manmade fiber that is durable, waterproof, lightweight and cheap. Gym sacks provide enough storage for a change of clothes, a drink, fruit or energy bar; ideal for taking to the gym.