#1 HIIT builds strength AND endurance
High intensity interval training has the dual benefit of burning calories AND building muscle. By performing exercises in quick succession with very little rest in between, you tap into your body’s two energy systems - aerobic and anaerobic.
This means you can improve your cardio AND build strength in far less time than performing cardio and strength training separately.
Individuals using a HIIT workout would expect to enjoy strength and improved conditioning benefits. However, one study found soccer players using HIIT over a 10 week period compared with traditional endurance exercise (running), also matched improvements in endurance. (6)
#2 HIIT burns a ton of fat
With its focus on strength training as well as cardio, performing HIIT workouts over a period of time will build more muscle. Greater muscle mass increases your metabolism, which burns more calories (7). This delivers a compound effect of stripping away even more fat, more quickly when following a structured program.
A study of 45 women compared a group performing “steady-state” exercise against a group who performed short high intensity workouts three times a week for 15 weeks. While both experienced improvements in cardiovascular fitness by the end of the trial, the group who performed the high intensity workouts experienced “significant” total body fat loss and in leg and trunk fat compared with the moderate exercise group. (8)
#3 HIIT dramatically improves your cardio fitness
One of the most important measures of health is aerobic - or cardiovascular -fitness. This is measured in the level of oxygen in your blood pumped by your heart to your muscles and how well your muscles use this oxygen.
Building aerobic fitness improves how well your whole cardiovascular system delivers oxygen - and energy - to your body.
Good cardio fitness reduces the risk of cardiovascular diseases, diabetes, strokes and high blood pressure. And, although aerobic fitness drops with age, you can restore this … if you know what to do.
A study of men aged over 65 compared health outcomes based on a low to moderate intensity program against a high intensity program. Researchers found those on a high intensity program were able to improve aerobic fitness significantly on a much lower volume of exercise (9)
The report noted: “Low-volume HIIT is emerging as a credible, well-tolerated and effective approach to improving aerobic fitness in aging men, irrespective of initial fitness levels”
#4 HIIT burns calories… even when you’re not exercising
Imagine being able to continue burning calories long AFTER you finish exercising. You can! HIIT workouts deliver a post-workout "afterburn”.
High intensity workouts trigger a process called post-exercise oxygen consumption (EPOC) which can burn calories up to 72 hours after you exercise. (10)
When you force your body’s aerobic system to work hard to take in oxygen faster, it takes longer for your body to return to its resting state. During this time, you continue to burn calories… even though you are no longer exercising. (11)
#5 HIIT improves glucose control and insulin resistance
HIIT has been found to benefit those suffering from diabetes in several ways.
One research study on individuals with type 2 diabetes found interval training produced greater improvements in body composition, aerobic fitness and glucose control. (12)
The study suggested the lower total exercise time commitment was a key factor in increasing physical activity levels.
Another study showed high intensity training could be effective in decreasing insulin resistance - an important factor in the development of type 2 diabetes.
#6 HIIT costs NOTHING
Now, isn’t that music to your ears? High intensity interval training is based around using just your bodyweight.
This means you can do it safely at home with NO gym and NO specialized equipment.
The requirement for no equipment or cost while being HIGHLY effective is why it is so popular with the military who use HIIT programs to stay fit and effective no matter where they are stationed. (13)
#7 HIIT is safe
I know what you’re thinking... “high intensity sounds a bit intense. Is it safe?!”
You have absolutely nothing to worry about.
As I will show you, HIIT training is not only hugely effective and quick, it is COMPLETELY SAFE. In fact, it significantly reduces your chance of injury because it is LOW VOLUME, meaning you don’t need to work out for as long.
A major review of 17 research studies involving 953 participants in the Journal of Sports Medicine concluded high intensity training was superior to medium intensity training for improved cardiorespiratory fitness. (14)
The study also reported that, despite the higher intensity, HIIT was as safe as medium intensity training.