High Intensity Interval Training: The Basics
One of todays’ hottest fitness trends is the increased application of high-intensity interval , or “HIIT” for short. Given the highly versatile and efficient nature of the workout, this shouldn’t come as much of a surprise. The basic concept of HIIT is to intersperse brief intervals of maximal exertion with short periods of rest or low intensity exercise. This approach can be applied to different types of exercise like running, cycling, or weight training. A runner, for instance, would spend five minutes running at a maximal speed, followed by one minute of walking or jogging lightly, before repeating the cycle. Can this really be all that effective?
The Science behind High-Intensity Interval Training
Whether you’re near peak physical fitness or just getting back in shape, you can expect significant improvements with a smart HIIT program. Like most other forms of regular exercise, HIIT is an effective way to improve cardiovascular health, cholesterol profiles and blood pressure. Current scientific literature also provides ample evidence of the benefits over other workouts:
- Compared to moderate intensity continuous training like jogging, HIIT has been shown to be more effective at improving brachial artery function
- HIIT has been shown to be a viable method for significant fitness improvements over short periods of time
- Studies of highly trained athletes point to significant improvements in overall performance through HIIT
By definition, high-intensity interval training is strenuous, and it’s recommended that you reach a basic level of fitness before implementing a more rigorous training program. You should also check with your physician if you have any existing conditions that could cause complications.
Once you’re ready to get started, you’ll want to tailor a HIIT program that addresses your particular goals and pace yourself based on your level of personal fitness. It’s important to remember that HIIT programs tend to be more mentally and physically demanding, so it’s important to give yourself ample recovery time between sessions. Starting out, you may want to plan on no more than 1–3 sessions a week. Eventually, your rest periods should decrease in length and frequency, and your bursts should become longer and more intense as you improve in your overall fitness.
In any application, HIIT relies on pushing yourself to maximal performance repeatedly over the course of a workout. The intervals of intense exercise deplete your muscles’ glycogen stores and put your body in an anaerobic state before allowing it time to obtain some oxygen in the rest interval. This repeatedly pushes your cardiorespiratory system to its upper limits, ultimately leaving you in a post-workout, oxygen-deficient state referred to as excess post-exercise oxygen consumption (EPOC). During EPOC, your body is working hard to get oxygen to replace consumed ATP, repair muscle tissues, restore body temperature and break down lactate. This means that for up to 45 minutes after your workout, your metabolism is pumped and you’re still burning calories.
As with any workout, you want to fuel your body with components it’ll need to properly recover. Opinions on which diet — protein- or carbohydrate-high — is the most effective differ, but both address the need for the body to recover with building blocks and fuel. Carbs will help replenish depleted stores of glycogen, while protein serves to rebuild muscle fibers. It’s likely that a combination of both is best (just avoid the fat!).
HIIT: The New Kid on the Block That’s Here to Stay
High-intensity training has proven effective, and it’s bound to have its proponents for years to come. Whether you use it for body building, cardio, or just overall physical fitness, HIIT can be an effective tool to get your body to the next level.