There’s one caveat, though: Don’t train your abs. (You’re welcome.) While you need to work abs most weeks, the point of workouts at this stage is to get the muscles that pump up well to swell further with increased glycogen storage. Since abs don’t get pumped like biceps or shoulders, it doesn’t make sense to drive glycogen into them—in fact, doing so can cause them to inflate too much, blurring definition.
Make sure that you don't get hungry by eating small portions throughout the day at regular intervals. Between your meals, eat a 150-calorie snack to keep your metabolism burning and to stave off hunger. Be sure that you don't eat a fattening snack such as sweets or crisps. When you're hungry, your body conserves calories and slows down your metabolic processes.
The next time you train that muscle group, decrease the starting weight by 5-10 pounds. If any of the HIIT 100s exercises are new to you, you'll need to spend some time figuring out how much weight you can do for 10 reps. The week before you start the HIIT 100s program, work these exercises into your training to get a gauge on appropriate weights. When estimating your 10RM, be sure to do the HIIT exercise first for that muscle group.
Here's something else most people probably don't know: Fidgeting is good for you. It's considered a nonexercise physical activity, and it's an important way to burn energy. You get more health benefits if, in addition to exercising, you are a more fidgety, more active person the rest of the day. This means gesturing while you're talking, tapping your foot, just moving around.