High intensity interval training, also known as HIIT, is exactly what it sounds like: exercise done at maximum effort but in intervals rather than continuously. A HIIT workout consists of very short periods of vigorous intensity followed by slightly longer periods of lower intensity recovery. The HIIT model can be applied to various forms of exercise, especially running.
Whether you devote longer chunks of your day to moderate exercise or want to squeeze in a quick, aggressive workout the choice is yours, if you’re pressed for time, HIIT might be the solution you’re looking for. The average HIIT session lasts from 10 to 30 minutes. Because it involves repeated periods of maximum effort, it burns calories quickly and is more efficient than options such as strength training or moderate intensity cycling. It also results in a post-workout metabolic increase that lasts up to 48 hours, which means you’re still burning more calories even after you’ve hit the shower.
Increased exercise intensity does more than just reduce the length of your workouts. HIIT is a type of depletion workout, which means if done correctly, it can use up your glycogen and get to your fat stores.
Glycogen is dietary carbohydrate that hasn’t been used yet. When you eat carbs, they’re converted to blood glucose. Your pancreas secretes insulin which sends this glucose where it’s needed for fuel, and anything leftover is stored in your muscles and liver as glycogen. When your glycogen reserves are full, the rest is stored as fat.
Exercise that’s done at a high intensity burns through glycogen stores quickly. Next in line to be used for fuel is stored fat, making HIIT a good fat-burning option.
HIIT can help you shed and keep off excess pounds by increasing your insulin sensitivity.
Insulin is the hormone that enables you to use dietary carbs as fuel or store them as glycogen or fat. If you are less insulin-sensitive, it means that your body responds poorly to the insulin you have, so your pancreas tries to help by secreting more.
Insulin blocks leptin, which is an appetite suppressing hormone. If you have a large amount of circulating insulin in your blood, your brain doesn’t get the message from your secreted leptin signaling that you don’t need any more food. You feel hungry and eat, which in turn stimulates more insulin secretion, which blocks leptin even more.
HIIT increases your insulin sensitivity. This means that the insulin in your blood works better, so your pancreas secretes less. With less circulating insulin in your blood, the leptin hunger suppression signal can reach your brain, enabling you to control your appetite. When you are hungry it’s because you need fuel, not because of disrupted hormone signaling.
HIIT is challenging and might seem intimidating to get started with. The most effective and easiest way to try HiiT classes is with boutique fitness classes that are taught by amazing instructors with expertise in High Intensity Interval Training. Specifically, Studio lets you experience HiiT classes for a fraction of the price of in person fitness classes. Studio is also more convenient as classes can be taken anytime on your iPhone from any treadmill or outdoors. Head Instructor Lisa Niren, is one of the best instructors in the world when it comes to HiiT and has created a signature workout called HiiT It.