How does it work?
The majority of endurance workouts, such as walking, running, or stair-climbing-are performed at a moderate intensity, or an exertion level of 5-6 on a scale of 0-10. High-intensity intervals are done at an exertion level of 7 or higher, and are usually sustained for 30 seconds to 3 minutes, but they can be as short as 8-10 seconds or as long as 5 minutes; the higher the intensity, the shorter the speed interval. Recovery intervals are usually equivalent to or longer than the speed intervals.
High-intensity interval training is done at a submaximal level; around 80-95% of maximal aerobic capacity. Sprint interval training (SIT) is a type of high-intensity interval training that pushes beyond this level to 100% or more of maximal aerobic capacity, or an exertion level of 10.
What are the benefits of HIIT?
The payoffs of pushing yourself with HIIT are numerous, and include:
Significantly increased aerobic and anaerobic fitness
Decreased fasting insulin and increased insulin sensitivity
Reduced abdominal and subcutaneous (just under the skin) fat
The amazing thing about HIIT is that it involves a very small total amount of exercise. By including HIIT as part of your exercise program, you can realize outstanding results in a short amount of time, which is good news for busy individuals.
Is HIIT safe?
High-intensity exercise of any type brings with it a higher risk of musculoskeletal injury and cardiac events. But together with healthy subjects, HIIT has been studied as a training method for people with heart disease and congestive heart failure. Under clinical supervision, subjects had been able to tolerate high-intensity intervals without negative effects. Most significantly, they experienced even bigger improvements in cardiovascular function compared to those undergoing continuous moderate-intensity training.
The bottom line? HIIT may or may not be safe for you. Check with your health care provider before adding it to your exercise plan.
How can I get started with HIIT?
Choose an aerobic exercise-like stationary bicycling. Warm up for 5 minutes, and perform just a few alternating speed and recovery intervals; 3-4 of each should be plenty and will give you a feel for it; finish with an easy cool down. Here’s an example:
|Time||Interval||Exertion Level (0-10)|
|22 min. Total Time|
|(4 min. total speed)|
HIIT protocols vary widely. There’s no one best single way to structure them. Experiment with shorter and longer speed and recovery intervals to find what works best for you.
Gradually work up to 8-10 or more speed intervals, depending on your fitness goals. Keep in mind that the most common mistake made with interval training is making the recovery intervals too short.
Perform HIIT workouts 1-2 times a week at most to reduce your risk of injury. This high-intensity training method is best used periodically for up to 6 weeks or so to enhance regular training rather than as a year-round fitness strategy.
For best results, work with a fitness professional such as myself to create a personalized HIIT training plan. HIIT requires a big, sweaty effort, but if you stick with it, chances are you’ll be rewarded with impressive results.
You can find more details on my training and nutrition by clicking HERE