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.
If you're specifically looking to target your belly, we have some bad news: you can't spot-target fat loss. That means you can do crunches or planks all day long, but you won't specifically burn belly fat. Instead, you can lose body fat overall, including from your belly. And by avoiding certain belly-bloating foods and with some strategic exercise, you will inevitably see results in your belly.
Drink sugar water once a day. This brain hack works by suppressing production of the hunger hormone ghrelin and is a small exception to the no sugar rule above. It was discovered by the late Dr. Seth Roberts, and tested and verified by Drs. Stephen Dubner and Steven Levitt, of Freakonomics fame. Done properly, it has a dramatic appetite-suppressant effect, making your diet much easier to follow.
Worried about hunger? There are a lot of simple tactics you can use to curb your appetite. Drink caffeine in the morning to kill your appetite until lunch, eat a lot of vegetables and protein, drink a lot of water, and make sure to have your sugar water at night. The first few days can be tough, but the hunger goes away a lot faster than you’d think.
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.