Recently I have been loving these series of exercises relating to high-intensity training in intervals. They do make me sweat and feel good afterwards.
This 7-minute workout came from the May-June 2013 issue of the American College of Sports Medicines Health and Fitness Journal. These 12 exercises of 30 seconds each and 10 seconds of rest in between have similar impact as a long run combined with weight-training, but all in 7 minutes. Whether this exercise is intense enough depends on how hard you push yourself, and the exercises are for anyone, especially those who are worried that they sit too much and have too little time for regular long workouts. You don’t even need to get out of the house.
From reading user experiences, these types of workouts are best done 2-4 times a week, or in 2 rounds with a brief resting interval in between, and in combination of longer workouts. But with any exercise, just by doing it already results in beneficial molecular changes in your body.