Seattle Forrest

This shouldn't be surprising. Interval training can be great for fitness and confers some health benefits, but does not have magical fat erasing properties. Unfortunately a lot of people believe otherwise because of bro-science and clickbait headlines all over the internet, so I thought this study warranted its own thread.

Cyclist0108

As always, I very much appreciate your posts. But WTF is "bro-science"?

mcours2006

Made up stuff, myths, misconceptions, stuff that a brah said to another brah at the gym, and it got passed on and on until it became 'fact' because sprinkled with some pseudo-science and real science it sounds plausible. Or just BS.

mcours2006

People are always looking for a short cut to weight loss and fitness. Burning twice as many calories in half the time, and getting the benefit of an afterburn sure sounds appealing, doesn't it? Or what about 10 minutes a day of high-intensity exercise is just as good as 30 minutes of running?

wolfchild

The biggest selling point of HIIT is fast results, everybody wants instant fat-loss results and instant fitness...HITT has become just like CrossFit they both have a cult-like following...The truth is that HIIT is not a "one size fits all approach" to fat-loss or fitness...You can't take a newbie who is out of shape and have them do Tabata intervals. A person needs to build some basic aerobic base before they even attempt any type of high intensity training...Majority of your training should be spend in lower intensity aerobic zones...Lower intensity work can be done everyday, HIIT can't be done everyday...While HIIT may produce faster results those results are temporary and will plateau after about 6 weeks. Lower intensity work will produce more consistent long term results then HIIT.
For best results do both but spend more time in the lower intensity zones.

wolfchild

The thing is that, 30 minutes of lower intensity work 60%-70% of your max is sustainable and can be easily done everyday, while sprinting at 90%+++ of your max everyday is not sustainable for very long term.

Cyclist0108

If anyone needs the full text

canklecat

If I'm reading the abstract correctly, they included only 31 of 6,074 studies. I wonder what their criteria were for selecting studies. Most studies I'd read on the NIH site supported the earlier assertions that HIIT was more effective.

I've downloaded the PDF to see if it goes into more detail about how they chose studies for the meta-analysis.

Altimis

What about stress?

Long exercise = more stress = body want to store more fat after?

wphamilton

One of the criticisms or challenges of meta-analysis in general is that they depend on published data, which has a built-in selection bias against that which merely confirms established theories. But my worry about this one is the possibility that the other variables influencing weight loss fluctuated across the studies and that this one represents a regression to the mean. In other words it may be true as far as it goes, but HIIT plus something may still be more effective than steady-state cardio plus something else, or vice versa.

Machka 

The weight gain after long exercise (like cycling a century or something) is usually just water weight.

Ride the century on Saturday ... appear to gain weight on Sunday ...Wednesday wear a path in the carpet to the toilet, and voila, the weight is gone on Thursday.

gregf83 

What makes you think long exercise is more stressful? It's much easier to ride at low to moderate intensity every day than it is to do HIIT.

My experience has been that to lose weight effectively it helps to be consistent i.e. better to ride for 1-2 hrs every day rather than 2-3 longer rides in a week. It's difficult and stressful to do HIIT and few people do it consistently day in day out through all seasons.

kingston 

At maximum intensity the average person is going to burn around 900 calories an hour, so 30 minutes of interval training is around 450 calories or 2 oz. of fat. If the same person goes for a 100 mile bike ride at an endurance pace of 16-17 mph, they’ll burn about 600 calories an hour for 6 hours which is 3,600 calories or around a pound of fat. I don’t see why we need a meta-analysis to figure that one out. HIIT makes you faster, but long rides in zone 2 make you skinny.

redlude97

How are the papers you've read defining effective? From the papers I've read HIIT burns more calories/min but the afterburn is minimal and you are limited in how often and how long you can go for so you are limited in total calorie burn

canklecat

Weight loss. Pretty much distills down to that.

I've read a few dozen papers and more abstracts, earlier this year before tackling HIIT myself as an alternative.

I do recall wondering about the methodology on some studies, but didn't bother bookmarking or making notes. They were all on the PubMed site. I was skeptical after reading some claims in pop culture fitness magazines.

Apparently the meta-analysis was designed to weed out the papers of questionable methodology, or those that didn't match a narrow set of standards to ensure comparable results. In which case, yup, 31 of 6,074 total studies sounds about right.

I can't say whether HIIT made any difference in my own weight. I was around 160 lbs last year, same this year -- only a few pounds above my optimal weight 30 years ago. Maybe a bit leaner and better toned than last year. Definitely some improvements in fitness, notably recovery between hard efforts and, to a lesser extent, in average speed over the same courses in similar conditions.

But magical recipe for weight loss? Can't say from my personal experience. I weighed 205 lbs about 15 years ago after car wreck injuries limited my mobility for several years. But I pared that down to 175 just with diet and very light exercise, a few walks a week. So by the time I resumed cycling in 2015 I didn't have much weight to lose.

I'm at the point where I'd need to give up beer, sugar, carbs after exercise, etc., for that extra 5 lbs of fat. I'm not really that concerned about a few more pounds. And might need to ride more often, longer rides at a moderate pace, rather than HIIT. Don't really have time for that now, so HIIT is more practical at the moment.

redlude97

What were they holding constant to compare the groups to conclude HIIT results in increased weight loss?

canklecat

It's been a few months since I read those studies on PubMed and my browser cache and history auto-clear every month so I can't easily find those same papers.

Best I can recall, there were indications that HIIT was measurably better for glucose metabolism. That was a concern of mine since diabetes runs in my family and I have a history of hypoglycemia. But those studies seemed to indicate otherwise similar benefits with both HIIT and MICT exercise.

Another study that was cited/linked by some pop culture fitness articles involved a limited study of obese Chinese subjects (if I'm recalling correctly). The methodology seemed fishy to me. In part that may have been due to the problem of translating into the rather dry English language of the PubMed format.

After awhile reading enough of those studies everything blurs together.

BTW, I'm not married to the concept that HIIT is better for weight loss. I don't have a horse in this race. My weight is already good. If it turns out HIIT and MICT are comparable for weight loss, so much the better. Suits the schedules and preferences for all concerned.

redlude97

yea not trying to argue one way of another. Both work as this meta analysis shows. People should use the one that fits their time schedule, fitness levels, and personality types, because weight loss is about consistency and maintaining more than anything. I was more curious because obvious you or I haven't read even a small fraction of the 6000+ publications on the subject.

canklecat

Yeah, the meta-analysis alone is admirable if only for the sheer tedium of sorting through so many studies to find relevant data and methodology.

Seattle Forrest

How many people in this thread ride with a power meter? How many kJs do you typically get from 20 minutes of short and punchy hill repeats vs some four hour loop?

In the summer I do hill repeats weekly, alternating between a 5 minute hill one week and a 30 second hill the next. These workouts have excessive recovery demands, that's why I only do them once a week. (We're out of season now and there's no call for any of that.)

I'm trying to maintain my weight but will probably gain a bit over the winter while I lift. In the spring I'll have to come back and lose the fat. An hour or two on the bike after work is a better option than sprint intervals or hill repeats, I can go longer, I can do it more often, and it's more pleasant too.

redlude97

the math is pretty easy. 300W=~300cal/hrX20 mins(0.33h)=100 cals, Assuming another 40 mins of 100w warmup/cooldown=~133-50 calories. Now a 4h ride at say 120-150w=120-150 calorie/hrX4=480-600 calories.

mcours2006

Training for performance and training for weight loss are completely different things. HIIT is great if you're training for performance, and especially if you've built a substantial enough base--i.e. lots of weekly miles. But for beginners looking to lose weight this is the wrong way to go and is a good recipe for quitting. Diet paired with moderate intensity exercise is the best way to go about it. Furthermore, diet and daily activity--walking, general movement, taking stairs, is the best way to lose weight. Studies have shown that daily general movement is much, much more important to someone trying to lose weight than say 30 minutes on the treadmill.

I realize the title is 'fat loss', but for most people fat loss and weight loss are the same thing.

kingston 

I normally use an equation that includes a factor for human efficiency:
energy (kcal) = avg power (Watts) X duration (hours) X 3.6

So a 20 minute ride at 300 avg watts is more like 360 calories and a 4 hour ride at 100-150 avg watts is around 2,000 according to my calculations.

Here's an article about it

redlude97

Doh! I did include that(1w~=1kcal/s) just forgot to convert from hours to seconds (3.6)

Boondocksaints

So the article is basically saying exercise + healthy diet = weight loss. Wow - how enlightening.

I don't agree at all that the most effective for weight loss is moderate intensity cardio and a good diet.

The best recipe for weight loss is good diet, cardio (moderate AND HIIT) AND resistance training (weights in the form of actual weights or body weight exercises - pullups, pushups, etc)