When it comes to workouts, we’ve all heard the term High Intensity Interval Training (or HIIT) being thrown around, but does it even work? According to science, it does.

Here’s the low down.

When you’re doing steady state cardio (walking, jogging, elliptical, etc.), your body is still using oxygen. Your body breaks down carbohydrates and fats for energy in the normal processes of metabolism and can continue doing so for extended periods of time.

When you’re sprinting or pushing at max effort (90% of max heart rate), your body cannot use oxygen and therefore, cannot obtain maximum speed for a long time. So when you’re finished, your body needs to obtain more oxygen to replace the oxygen used. This helps you continue burning calories even after your workout is done.

You also activate your fast twitch muscle fibers when your slow twitch muscles burn out. Slow twitch muscle fibers help you build your endurance, while fast twitch muscle fibers help you build your muscle tone.

HIIT workouts have short bursts of maximum effort that increase your energy needs, then longer times of low effort to allow your body to recover for the next spurt of max effort.

The biggest advantage is that you burn more calories in a shorter period of time. When your current energy stores run out, then you access the glycogen (stored carbohydrates) in your adipose tissue, burning stored fat. The rest periods of HIIT workouts prevent you from burning muscle. This makes these types of workouts perfect if you are looking to lose fat and gain muscle.

Let me break it down to the main advantages:

  • You burn fat instead of muscle.
  • You continue burning calories after your workout is done.
  • It is super efficient (20-30 minute sessions are recommended).
  • It can be done anywhere and can include a variety of machines, stairs, and plyometrics.
  • Improves your circulatory system.
  • Boosts your metabolism.
  • It’s fun and challenging at the same time.

So how do you do them?

The great thing about HIIT workouts is that you can mix it up. Change up the lengths of sprints, rest periods, inclines, and scenery to find out what style you like best.


Try switching off between thirty seconds of sprints and one minute of rest for 20-30 minutes.


Try 15 seconds all out, 15 second low intensity, and repeat three times, then rest for one minute.


Try low resistance and rotate between sprints for 30 seconds and low intensity for 30 seconds to one minute.


Apply the same concept as the treadmill at whatever resistance you feel comfortable with.


Try picking six movements (like jump squats, lunges, kettle ball swings, etc.) and do five rounds of 20 reps of each movement.

#SpoonTip: Use a heart rate monitor to ensure you are getting your heart rate up to 85-95% capacity.

Get ready to sweat, Spoonies.