HIIT nearly 30% better than MOD for fat loss

Spike_G

Yeh OK that seems a bit of a click bait title but read the article as it's a study by the British journal of sports medicine.

Don't forget you can't exercise out a bad diet!

Link to the original source journal article that is open access and full-text.

https://bjsm.bmj.com/content/early/2019/01/23/bjsports-2018-099928

Conclusion Interval training and MOD both reduce body fat percentage (%). Interval training provided 28.5% greater reductions in total absolute fat mass (kg) than MOD.

Citation: Viana RB, Naves JPA, Coswig VS, et al Is interval training the magic bullet for fat loss? A systematic review and meta-analysis comparing moderate-intensity continuous training with high-intensity interval training (HIIT) Br J Sports Med Published Online First: 14 February 2019. doi: 10.1136/bjsports-2018-099928
 


NorthCascades

Fat loss basically comes down to calories. HIIT is a 20 minute workout where half the time is resting. Because the other half is at such high intensity, it stresses your CNS, you need a lot of recovery time, so you can do it two or three times a week. That's not ideal for fat loss. I mean by contrast I've spent six hours cross country skiing at a variety of intensity levels over the weekend. Lots of people do long hikes and bike rides. Exercising for hours always burns more calories than exercising for minutes.

claireychn074

One of the theories appears to be that HIIT doesn’t raise the appetite as much as longer workouts - all v interesting, but the best form of exercise for health and / or calorie burn has to be one you really enjoy and want to keep doing.

sijomial

"HIIT nearly 30% better than MOD for fat loss"

Yes that headline is very much in the style of the Daily Mail - a more accurate interpretation would be that people who exercise with higher intensely are slightly more successful at losing fat. Which perhaps means there's a lot of selection bias.
More people that are prepared to push themselves harder are successful at losing a bit more fat?
People with the physical capacity to exercise at a higher intensity are ultimately slightly more successful?

Caveats that spring to mind.....
Lumping HIIT and interval training together muddies the waters immensely, not all higher effort interval training is HIIT. From the posts on these boards about 90% of what people call HIIT simply isn't. A lot of what is described isn't even that intense, a good proportion isn't even cardio!
Have a look at all the multiple search strings used to compile the sample.

How many of the studies selected actually had people tracking calories? Without knowing that then what caused the marginal difference in total fat lost? Increased muscle? Higher protein intake? Better compliance?

As an example of what @NorthCascades says here's the trace of my last interval session (intense cardio but not HIIT).
Although it was extremely exhausting, made me starving hungry, probably caused me to reduce my activity the rest of the day and needed recovery time the overall calorie burn was just over 500 net cals/hour.
That rate of burn is my easy pace outdoor cycling which I can do for hours on end with very little hunger, no recovery and huge calorie burns. ( @claireychn074 I'm someone who moderate exercise has very little hunger response but for intense cardio or weights my hunger is far higher than the actual calories expended.)

claireychn074

Interesting, I’m actually the opposite. I can do HIIT or high intensity cardio (and yes I do agree they are not the same) without being hungry, but lifting or endurance exercise makes me absolutely starving!