Is HIIT(high intensity interval training) better for fat loss then LISS(low intensity interval) training?

HIIT is short, high effort sprints, between 10- 30 seconds, spaced with low intensity steady state work.

Example:

5 minute warm up.

5 rds:

20 second max effort row.

2 minutes of easy pace in between.

5-minute cool down.

LISS is something like walking on treadmill, at a steady pace, without maximal exertion.

For the longest time LISS was said to be the better cardio of choice because it burned more fat as fuel during the session, and HIIT uses more carbs as fuel.

Both of these are true, but what really matters is what happens to fat balance over a 24 hour period.

HIIT training has become popular over the years because even though you might not burn as much fat during your session you will after the session has ended with what we call EPOC(exercise post oxygen consumption).

So, while you are watching the show Friends late at night your body continues to burn fat, because you are consuming more oxygen hours after you have completed your HIIT session.

And with steady state your caloric burn comes just from the session itself.

But what you might not know is that the EPOC effect isn’t as important as we thought…

The extra calorie burn doesn’t account for any apparent greater fat loss potential.

Did you know…

30 minutes of either HIIT or LISS cardio burn roughly the same number of calories?

So then why HIIT?

  • Slightly more time efficient
  • People tend to push themselves harder
  • Not as boring as LISS, so easier to adhere to

BUT…

HIIT is more difficult to recover from especially if you are also weight training.

Especially when our goal is to reduce bodyfat while maintaining as much muscle as possible.

And if you think about it, weight training does somewhat resemble HIIT…

 

Both have a 20-30 second all out bouts with a 2 minute rest, repeated during your session.

Which means you could make an argument you get all the benefits if HIIT with weight training.

Remember that cardio should not be your primary vehicle for fat loss, instead it should come from your diet.

Plus, something to remember is that HIIT is harder, and tends to take longer to recovery which could hinder your weight training session.

So…

If you do decide to include HIIT in your training pick a safer modality like a rower or bike instead of sprints and only do 1-2 sessions a week, plus make sure your HIIT sessions are not the day before leg day!

When deciding HIIT or LISS…

Just pick a method that works best for you, your schedule, and you can adhere to it.

I personally don’t do any HIIT. I train hard with weights, walk my dogs for cardio, and adjust my diet as I see fit for fat loss, and muscle building.

-Evan, evan@forge-rx.com