For its biggest marketing push to date, Gatorade is throwing it back to the ’90s. The PepsiCo brand’s latest campaign, called “It Hasn’t Changed,” is based on a decades-old tagline, “Is it in you?,” which anchored a campaign hinging on the idea that drinking Gatorade would help athletes perform at their peak. This year’s reboot, like other media from the ’90s and early 2000s that have seen recent revivals, has a slightly different message. Youth participation in sports tends to drop off considerably around high school, and “It Hasn’t Changed” is centered on addressing that drop-off by showing young athletes that they already have what it takes to be great, Anuj Bhasin, Gatorade’s chief brand officer, said.