Over the last few years, HIIT has hit the fitness world and promises a great workout designed to help athletes reach performance goals. The average gym goer picked up on this workout and has never looked back. I have been using this type of training for my own workouts on occasion as well as with many of my clients looking to break through a plateau, increase athletic performance for sports such as soccer, hockey etc. and increase caloric burn.
How does it work?
Most 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 typically sustained for 30 seconds to 3 minutes, although 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 equal 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.
Benefits of HIIT
-Significantly increased aerobic and anaerobic fitness
-Decreased fasting insulin and increased insulin sensitivity
-Reduced abdominal and subcutaneous (between the muscle and skin) fat
-More efficient circulatory system
One of the greatest benefits is that it's a brief, intense workout that can be done in 20 minutes. This is good for those days when you may have time constraints due to work or other commitments.
Is HIIT safe?
High-intensity exercise of any type brings with it a higher risk of musculoskeletal injury and cardiac events. But with healthy people, HIIT has been studied as a training method for people with heart disease and congestive heart failure. Under clinical supervision, people were able to tolerate high-intensity intervals without negative effects. Most importantly, they experienced bigger improvements in cardiovascular function compared to those undergoing continuous moderate-intensity training.
The bottom line... As I always recommend, check with your physician before beginning this or any other exercise program to ensure you are fit enough and able to perform the workout.
Getting Started
Choose an aerobic exercise such as the stationary bike or elliptical trainer. Perform a warm up at a modest pace for the first 5 minutes or so. Once you have started to break a sweat and feel the muscles and joints are warm, increase your intensity by sprinting at 70-90% your max effort 30 seconds to 1 minute. Follow this with a 1-2 minute recovery period (you can manipulate the recovery to suit your fitness level). Again, increase the intensity back to 70-90% effort for 30-60 seconds followed by a 1-2 minute recovery. As your body adjusts to the intense workout, increase the intensity more toward the 90% effort level. If you are giving the "work" portion an honest 70-90% max effort, you should be spent after 3-5 intense rounds.
There are different ways to increase the intensity for the workout. For instance, if using a treadmill or elliptical trainer, you can either increase your speed, resistance or incline... or all three! If using a stationary bike or rowing machine, you can increase your speed and/or resistance.
Below is an example of a 20 minute HIIT workout
Time Interval Exertion Level (0-10)
5 min. Warm-up 3–4
1 min. Speed 7–9
2 min. Recovery 5–6
1 min. Speed 7–9
2 min. Recovery 5–6
1 min. Speed 7–9
2 min. Recovery 5–6
1 min. Speed 7–9
5 min Cool-down 3–4
.
Total Time 20 min.
As you progress, you can add more intervals and decrease the recovery time. However, don't cut your recovery time too short, you will rob yourself of the ability to give an all out effort on the speed/intensity portion.
I recommend not doing this type of workout more than 1-2 times each week for no more than 6-8 weeks. Again, if done properly, this is an intense workout that should not be attempted unless you have been cleared to do so and have a history of intense cardiovascular endurance. Contact myself or a Certified Personal Trainer if you would like a HIIT workout developed specifically for you.
*information compiled from ace.org