Stuck indoors on a rainy day is NO excuse to skip your workout. This is also a good one when you are short on time. I am using a pair of weights and my BOSU but you do not need a BOSU to do this workout.
It is a HIIT workout with 10 seconds of rest followed by 20 seconds of work. Remember to WORK during those 20 seconds. But please do go at your own pace and modify when needed.