Walmart offers the Stalwart 8-Piece TG EVA Foam Exercise Mat for $9.68. (Home Depot has it for the same price.) Opt for in-store pickup to dodge the $5.99 shipping fee. That's $2 under our May mention and the lowest price we could find by $6. Each tile measures 12.4"x 12.4".

Besides making exercise easier on the joints, this mat can also be used to protect your children and your hardwood floors from each other.