You can start using a baby gym and baby play mat as soon as your baby is comfortable lying on their back without being swaddled. While a newborn might not yet interact with various toys and textures, they'll enjoy just looking at dangling toys when alert. Your baby will get the most out of a play mat once you can introduce tummy time, typically around 3 months of age. When you start, you'll want to limit sessions to five minutes, with three of these short sessions each day. You can gradually work up to an hour of tummy time daily.