Live data from Hacker News

1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

pubmed.ncbi.nlm.nih.gov

51–60 of 506 posts

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#51
post #6

From the abstract: > We investigated whether sprint interval training (SIT) was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training […] Researchers are not claiming improved overall fitness as the Hacker News title seems to suggest.

True, that seems a bit misleading. But what is fitness if not something that can be measured as "indices of cardiometabolic health"?

I think fitness encompasses everything that makes you physically capable. Cardio metabolic is just one part of that.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#52
post #16
post #11

It's also a great way to get injured. Then you can't exercise at all.

Is it actually any more injury prone?

It's a fair question. I didn't see any mention of injury in this study and I never see it discussed in these threads. I also admit my bias, I'm an older runner, and I've seen a lot of people struggling, who've unwittingly, been over-optimizing training and just over-training.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#53

It's 8 minutes, not one minute The people in the study were out of shape to start with The improved measures were insulin sensitivity index, peak oxygen uptake, and "skeletal muscle mitochondrial content" No change in body mass In conclusion, if you're out of shape, you can improve a limited number of fitness measures just as much doing 3x8 minutes of higher intensity exercise as much 3×45m less intense exercise over…

Exercise doesn't result in changes in body mass (weight loss), unless accompanied with a diet. https://www.theguardian.com/science/2016/jan/28/study-reveal... .

I think it’s safe to assume that many inactive people start to exercise because they believe it will help them lose weight, however

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#54
post #36
post #24

The study apparently only involved male participants. The control group consists of 6, the two treatment groups of 10 and 9 participants. The total N of the study is 25 participants. They conduct a one-way ANOVA on the interaction of time and treatment group indicators. I conclude that the study is woefully underpowered. I do not trust the apparent significance of their results.

I really don't understand statistics. My interpretation of "the study is under-powered" is that since the study has so small groups it will be difficult to find any result that is statistically significant. But wouldn't that mean that for any effect to be significant the effect size would have to be huge? My hunch is that if you have a large enough group even very small effect sizes will be significant, but in small…

I studied this many years ago, but you have formulas for survey sizes based on confidence levels and, if I recall correctly, the number of variables you want to study.

People publishing these studies should know and use these formulas, but I imagine there's a lot of pressure to publish high impact/visibility stuff so they just go for the cheapest and fastest (aka wrong) approaches some times.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#55
People actually benefit from both low-intensity and high-intensity exercise. One is not a substitute for the other. Endurance athletes know this.

Low-intensity exercise conditions aerobic energy pathways (mitochondrial respiration) in ways that high-intensity exercise cannot.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#56

Research is important for research sake. But can anyone explain why these studies are like cat nip to the public and tabloids? "Any and All exercise is worthwhile (up to a limit)" and "unhealthy food bad for you" Over and over and over again...

Because a huge percentage of the populations (yours truly included) lives unhealthy lifestyles and they want an easy way out or they have aspirational goals (think New Year's resolutions) they will never reach and do like being reminded of them occasionally.

And tabloids frequently get to use cute/sexy pics for these articles, so more clicks.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#57
post #37

Earlier quoted context omitted.

Or you just eat less, which is probably going to change your body mass without exercise :-)

But still have low cardio fitness. A healthy body needs exercise and a good diet.

Question is, how to get that "exercise". I am going to be downvoted, but I am convinced sex twice a week is more or less sufficient for the "exercise" part.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#58

Earlier quoted context omitted.

Exercise doesn't result in changes in body mass (weight loss), unless accompanied with a diet. https://www.theguardian.com/science/2016/jan/28/study-reveal... .

Yes it can. I had an injury that prevented me from cycling for over a year and slowly gained weight. It all came off after resuming a normal routine without dietary changes.

A part of that weight gain is caused by no longer burning let's say an additional 500 calories a day from cycling, another part is due to lack of activity and muscle atrophy lowering your base metabolic rate. And all of this accounts to one thing: you eat too much for a sedentary lifestyle. Cycling just allows you to compensate.

So, sure, exercise helps at a certain point. But, take into account:

* If you're fat, your base metabolic rate is insanely high. Obese people are easily at 3000+ calories needed _just_ to maintain that mass.

* If you're fat, it's going to be almost impossible for you to do sessions where you burn 500 calories, simply because you're out of shape and possibly exercising injures you. Running isn't exactly good on your knees if you're overweight. Realistically, you'll do 200-300 cal sessions, at best, every day.

* If you're fat and you manage to burn these 500 calories... Good job, but that's less than 20% of your daily intake. Not eating something is infinitely more simple and efficient.

Our bodies are incredibly efficient at exercising without using lots of energy. Unless you do it for long and hard enough that you reach huge numbers of calories burned, diet is the most important component of losing weight.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#59

Earlier quoted context omitted.

Yes it can. I had an injury that prevented me from cycling for over a year and slowly gained weight. It all came off after resuming a normal routine without dietary changes.

Well whether you lose/gain weight depends on (caloriesIn - caloriesOut) it's no rocket science. If you didn't compensate anymore as much for lowering the calories out you're obviously going to gain weight.

So what you mean is your original comment could just have much said "exercice results in weight loss unless accompanied by a corresponding change in diet to increase calories intake", aka exercise alone as a change results in weight loss.

Re: 1min high-intensity exercise 3x a week improves fitness as much as 3x aerobics (2016)

#60

It's 8 minutes, not one minute The people in the study were out of shape to start with The improved measures were insulin sensitivity index, peak oxygen uptake, and "skeletal muscle mitochondrial content" No change in body mass In conclusion, if you're out of shape, you can improve a limited number of fitness measures just as much doing 3x8 minutes of higher intensity exercise as much 3×45m less intense exercise over…

such an important point here. The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan. I am doubtful that just 10 min exercise over a few years will get you in a better shape. Another factor greatly ignored is HRV as key indicator of recovery and response to an exercise. Andrew Flatt (1) is a researcher and has been studying h…

> such an important point here. The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan.

I'd bet that by the time they end up hitting that plateau it'll be a lot easier for someone who has been sedentary to up their game than it would have been if they'd started a more difficult and time consuming workout from the start. Easing into being more active seems like a really good thing and one that might make it easier for someone to start exercising and stay with it long term.

Post reply on HN