I have good news and bad news for you.
Good news…. If you hate spending hours doing cardio, then you will love this.
Bad news…. That “I don’t have time to exercise” excuse you keep using is getting chucked out the window for good.
What if I told you that you could:
- Burn Fat
- Improve Metabolic Health
- Improve Muscular Endurance
- Reduce your Risk for Diabetes
- Burn Calories After your Workout
- And Improve Cardiovascular Health
All in a 20 – 30 minute session, just a few times a week?
Sound too good to be true? It’s not. Welcome to Interval Training.
Please note, I am not a doctor. I have done research on this for my own use, but please consult your doctor before starting any exercise program.
What is Interval Training?
High Intensity Interval Training (HIIT) is actually a very simple but effective exercise. You will alternate short periods of high intensity work, followed by longer periods of low intensity work. In a 20 – 30 minute routine, you may do 15 – 20 minutes of low intensity work and 10 minutes or less of high intensity work. A powerful fat burning workout in less than 30 minutes with less than 10 minutes of actual hard work? You might be wondering…
Does Interval Training Work?
Regardless of intensity, exercise puts stress on your body. When facing this stress, your body adapts and grows to make it easier to handle the stress in the future. And despite being a short workout, it still puts great stress on your body, resulting in increased calorie burning and fat loss.
Studies show that:
- 7 sessions of HIIT over 2 weeks showed an increase in fat oxidation by about 30%, meaning you burn more fat with interval training [Journal of Applied Physiology (2007)] [i]
- A 15 week exercise program showed that interval training lowers insulin levels and can increase fat oxidation, showing greater fat loss in the long term[Medicine & Science in Sports & Exercise (2007)] [ii]
- Plus, this can be modified to be a program for obese patients. HIIT programs are more effective at lowering fasting glucose levels and improving metabolic health in those with Type 2 diabetes[Obesity Reviews (2015)][iii]
The point is, interval training is effective at burning fat, lowering insulin and glucose levels, improving metabolic health and helping your body adjust to intense workouts.
But does interval training work better than low or moderate intensity cardio?
But does interval training work better than low or moderate intensity cardio? A high intensity workout puts greater stress on the body, forcing it to grow more than during a low intensity workout. As with anything in life, what you put in is what you get.
Studies show that:
- 3 HIIT sessions per week for 8 weeks has been shown to increase VO2max (this is how well you utilize oxygen, a common measure of cardiovascular health) and increase fat loss [East Tennessee State University (2001)][iv]
- HIIT results in a higher energy expenditure over 24 hours, meaning that you will continue to burn calories after your workout[Medicine & Science in Sports & Exercise (1996)][v] Why? This is a difficult workout so your body will work harder to recover and will use more energy (calories) even after exercise.
- HIIT is superior over low or moderate intensity training for reversing the risk factors of metabolic syndrome (conditions that increase risk of heart disease, diabetes and stroke) in a 16 week study of 32 adults with metabolic syndrome [Circulation (2008)] [vi]
Interval training is more effective at burning fat, burning calories after a workout and improving metabolic health than standard low to moderate intensity cardio.
Sounds good, but how do I get started?
You will have one short period of high intensity exercise, followed by a longer period of easy exercise. Now repeat. OK it’s not quite that simple, but almost!
Do I have to run? I really hate running….
Of course not! Anything you enjoy that can get your heart rate up, then allow it to recover is perfect.
Running is a great choice as it is easily adaptable; you can adjust speed and incline on a treadmill or take it to the streets. If you are in good shape, try sprinting then jog for recovery. Just getting in shape? Try a light jog followed by a recovery walk. You want to adjust at your own pace and listen to your body.
Bad joints? Try a bike, agility ladder, rowing machine or elliptical machine. This is an incredibly customizable program that can be tailored to your goals and favorite exercises. Any form of cardio works as long as you can alternate intensity.
Try rope slams, box jumps, jump ropes, the Jacob’s Ladder, anything that gets your heart rate pounding!
High intensity sounds…. Intense…. How intense?
Pretty intense, keep in mind we are trying to get a solid workout in 30 minutes. But don’t be scared of that because it will be short then you can recover.
You want the high intensity period to be about 80% or higher of your max heart rate, and the low intensity period to be about 40-50% of your max heart rate. For those of us that do not use heart rate monitors a lot, this means high intensity should feel difficult, it should be difficult to carry a conversation and you should feel like you really put work in. The low intensity period should feel comfortable, it is a recovery phase and should help bring your heart rate down. But keep moving!
How Long Should I Do This?
Short answer: Maybe 30 seconds to 1-minute high intensity and 1 minute to 2 minutes recovering. However….
A 1:3 or 1:4 ratio is a good starting point while adjusting to this program[vii]. For example, this can mean high intensity for 30 seconds, recovery for 1 minute 30 seconds or 2 minutes. Listen to your body and do what feels right. You are pushing yourself but only by your standards, not anyone else.
As you advance, try a ratio of 1:1. High intensity for 1 minute, recovery for 1 minute. As your body adapts you want to continue pushing yourself by either reducing recovery time or increasing effort.
How many times should I do this?
Another short answer: about 5 to 12 times (high intensity + low intensity = 1 time), but this will vary.
Repeat this to make up a 20 to 30-minute workout. You may repeat this anywhere from 5 to about 12 or 15 times depending on how long your intervals are. The idea is to reach a 20 to 30 minute workout and put a lot of effort into the high intensity periods.
The ACSM recommends doing one HIIT routine per week while starting out, then increase to two routines per week[viii]. Make sure you give yourself time to recover between each, but you can even do this 3 times per week as you adapt.
If you would like to know more about HIIT and enjoyed the information here, take a minute and check out The Impossible Life!