The major reason HIIT works so well for dropping body fat is due to the greater calorie burn (or EPOC—excess post-exercise oxygen consumption) that's maintained after the workout is over. In other words, you burn more calories and more body fat while you're sitting around doing nothing. In addition to this increase in resting metabolism, HIIT is effective at enhancing the mechanisms in muscle cells that promote fat burning and blunt fat storage.
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.
Gale co-founded SkinnyMs. with a goal to provide women with delicious & clean recipes, fitness routines, and healthy ways to reach their ideal weight. Guided by her firm belief in clean eating and the power of exercise, Gale has written two cookbooks and several fitness ebooks. She earned her Fitness Training Certification from, National Exercise & Sports Trainers Association. Gale loves to run and has completed numerous half-marathons.
For even more impressive effects on body composition: aim for exercise forms which elicit a positive hormonal response. This means lifting really heavy things (strength training), or interval training. Such exercise increases levels of the sex hormone testosterone (primarily in men) as well as growth hormone. Not only do greater levels of these hormones increase your muscle mass, but they also decrease your visceral fat (belly fat) in the long term.
“Exercise should not be used to purge calories,” Albers says. “Instead, to boost your mood to keep you motivated.” The thing is, exercise is great for you and can make you feel awesome. And feeling good about yourself seems to be actually useful in weight-loss efforts. Plus, some research has shown that changes in exercise behavior can lead to changes in eating behavior. “In part, it is neurochemical. Movement and exercise you enjoy boosts your serotonin and dopamine levels, which makes you feel good all the way around,” Albers says.
In a way, moderate-intensity physical activity is that "magic pill" a lot of people are looking for, because the health benefits go beyond keeping your waistline trim: Not only can it reduce your risk of cancer, stroke, diabetes and heart attacks, but studies have shown that physical activity can significantly improve the moods of patients with major depressive disorders.