Long summer days spent licking ice cream cones at the beach and backyard barbecues are the last places you want to have to think about your diet. Unfortunately, they’re also the places you’re most likely to stress about it. Luckily, many of the activities you’re doing all season also happen to double as excellent calorie burners. We’ve rounded up nine of the most surprising (and most effective) ways you can burn calories in just 30 minutes all summer long.