A new feature in the Subway app allows users to choose between sparkling water and energy water drinks.
The feature, which was announced today, will roll out to all subway card readers on July 31.
“In the near future, we are excited to introduce the ‘Sizzle’ option for our customers who want to save some time while enjoying delicious beverages with their favorite Subway sandwich,” Subway spokeswoman Rebecca Foll said in a statement.
“In addition to sparkling water, the ‘Energy’ and ‘S’ options also offer customers the ability to choose their favorite energy drinks from our entire portfolio.”
Energy drinks, including those with sugar and caffeine, can be more expensive, but energy drinks like Starbucks’ and Coke’s energy drinks tend to be healthier, according to the Food and Drug Administration.
Energy drinks are a growing market, with nearly $3 billion in energy drinks sold last year, according a 2015 report from the National Beverage Association.
Energy-filled drinks are usually made with water and sugar, and contain sugar and/or calories.
These drinks are popular because they are easy to store and can be delivered without hassle, according the National Association of Chain Drug Stores.