(CNN) — We all have days when there’s no time to get to the gym. So we wondered: Which close-to-home cardio activities blast fat fastest? Wonder no more. Here are the top seven fat-and-calorie burners, from Los Angeles based celeb trainer Ramona Braganza, who has helped shape the amazing bodies of stars like Jessica Alba, Halle Berry, and Anne Hathaway. Try any one of these, and you'll boost your metabolism for up to a whole day afterward. One small workout, one giant payoff. 1. Inline skating Burns 425 calories in 30 minutes Surprised? While skating might be so much fun you forget you're actually working out, it's also numero uno on our list when it comes to blasting fat and calories. The big burn stems from the side-to-side movement of your thigh and butt muscles (demanding more from your body than the straightforward motion of our number-two activity -- running). And your core gets involved in a big way to keep you balanced. What's more, you get all these benefits without putting too much stress on your knees and other joints. Skate at a strong, steady pace. Don't forget your helmet, wrist guards, and knee and elbow pads. Boost the burn: Alternate one minute of hard skating with one minute of medium-paced strokes. 2. Running Burns 374 calories in 30 minutes The typical runner's shape is sleek and lean, and there's a reason for that: The major running muscles -- legs, butt, core -- happen to be the biggest calorie-and-fat-burning muscles in your body. To get the most ...