Biking is the celebrity go-to workout this year, and actress Blake Lively is joining in on the fun and the cardio: The starlet and boyfriend Leonardo DiCapriohit the streets of N.Y.C. recently with for some cycling. Biking can be leisurely under 10 mph, but if you speed up a bit to 15 mph for a vigorous ride, you can burn approximately 700 calories, according to studies. In fact, hopping on a stationary bike at the gym can burn just as many calories as doing the real thing outdoors. Take advantage of the sunny weather in the weeks to come to get outside for Blake's favorite, fun workout.