A single weekly bout of exercise may reduce cardiovascular mortality (2006) | Hacker News Reader

A single weekly bout of exercise may reduce cardiovascular mortality (2006)

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60 pointscpncrunch42 comments

This study is 17 years old and from an era before physical activity tracking devices like smartwatches became widespread. As such the findings were based on subjective answers given by participants to questionnaires and in interviews. There are likely more recent and more informative studies published now.

Conclusion: "These results challenge the current recommendation that expenditure of at least 1000 kcal per week is required to achieve exercise-induced protection against premature cardiovascular mortality."

Just as a note -- that's a good amount of exercise, even if once a week. Burning 1,000 calories is a lot of physical movement.

Running a 5k 3x a week is more or less a minimum standard and is roughly 1k calories for a average person.

Walking the same amount isn't too far off either. And easier to do for most people, IMO.

Running or walking a set distance burn about the same amount of calories, it's just a matter of how much time it takes.

According to this article walking burns about 30% less, but still closer than I would have expected!

https://health.clevelandclinic.org/qa-can-you-burn-the-same-...

I'd probably wager that with walking you can go up way steeper inclines than you can otherwise comfortably jog. That might change things considerably. According to one study you burn over 30% more calories walking up a 10% incline (about 17% calories much for a 5% incline).

https://www.sciencedirect.com/science/article/abs/pii/S00219...

This is supposedly not true. Walking the same distance expends more calories (on account of using your energy-inefficient machinery for longer to achieve the same external work).

Equally, walking the same amount of time as a run expends less calories because of the greater effort involved in running to generate more external work.

is that true? I feel fine after walking 5k but can barely run 5k without wanting to pass out or sweat up a storm

is that true?

What an odd question. Moving on...

I feel fine running a 5K in 30 minutes. If I cut that down to about 18 minutes, yeah, I sweat up a storm, too. I don't know why it would be unexpected that the faster you go over a set distance, the harder it's going to be.

>> Does walking and running consume the same amount of calories?

> What an odd question.

Normal people would question this assertion, rightly so. Running takes more, unless you're walking at a running speed. Basic thermodynamics.

I know the Apple Watch can be very inaccurate in measuring energy expenditure, but I weigh about 175-180lb and my ~6k runs almost always register at 450-600kcal.

I have a simple gps watch that uses my weight to estimate calories and doesn't measure heart rate. It gives me the same as you, just under 100kcal/km for the same weight. But I'm convinced this is a dramatic overestimation, I run a lot and have for years, and I'd be eating way more if I really burned that much. I think with regular exercise we become extremely efficient and the calorie burn goes way down. I don't know if heart rate accounts for that or not, but overall I'm sceptical about calorie counts.

It definitely depends a lot on metabolic adaption which already varies significantly person to person but I think for beginners just moving from a sedentary lifestyle it's a good estimate for a while (six months to a year is the number I've heard, depending on training intensity).

The last few months I've gone from a sedentary lifestyle to calorie counting and using an Apple Watch to track exercise with an intense 7-10 mile walk/run/hike 5-7x a week. With the weightloss I've experienced it seems relatively accurate (within 20%) but that's with 2-3 hours of exercise (not including weight lifting) per session.

When playing beat saber, I always assumed the Apple Watch over-estimates calorie burn if only because the watch is on the part of your body that's the most mobile (your wrist). So, getting 300kcal for a 30 minute session felt like cheating.

But, there's at least "more legit than an Apple Watch" evidence that the calorie burn is that high; 6-8kcal per minute on Expert difficult [1], and some of the Expert+ tracks could easily burn more than that (and, I weigh much more than their Standard Reference Person).

I'm not the most fit person, but I've seen surprisingly little hard evidence that the Apple Watch grossly under or over-estimates calories burned. I imagine it starts getting worse at the extremes, and nothing is perfect, and everyone is different; its an area where more research would have unbelievably high leverage (Apple has sold, hundreds, of millions, of watches) (in fact: I'm sure they've done some of this research themselves).

[1] http://vrhealth.institute/portfolio/beat-saber/

Not sure where you're getting that number, from but 3 miles for me usually only burns ~500 calories (according to apple watch/strava)

EDIT: I weigh ~215 pounds

It's 1kcal per week and running 3x a week. So your 500 calories is 1.5kcal for the week if you run 3 times.

It's saying the previous recommendations were 1000 calories a week. This study found that a 45 min workout using 631 kcal produced similar cardiovascular benefits. But yes, 631 kcal during a 45 min high intensity workout is still quite a lot.

Yes, it is quite a lot. The average American would probably need months of training to even be able to complete such a workout.

Yeah that's somewhere between a 5km and 10km run. If you're in shape to pick up and do that once a week, you're in better shape than most people and so it's not really a surprise that such people have lower cardiovascular mortality.

I'm not sure I would agree that most people are physically incapable of running 3 miles once a week. Unless you've got a physical disability or some very bad respiratory ailment you can do that in well under 40 minutes at a pace barely faster than walking.

Obviously everyone's different (weight, fitness etc.), but 100 calories is a decent estimate for expenditure while running a mile. So 1000 calories might be somewhere around 10 miles.

Meanwhile an e-bike could probably go 50 miles at the same speed with the same energy (about 1.2kwh)

The point is to improve cardiovascular health, not debate the most efficient transportation methods.

Yes, but you won't gain much cardiovascular health from that.

> Burning 1,000 calories is a lot of physical movement.

Divide that by 7 days per week and it’s only 142 calories per day.

The average person can burn that many calories walking a mile or mile and half. If you take your phone and answer emails while walking you’ll get there.

Some of the estimates in this thread claiming 10 mile runs are necessary are way, way off the mark.

> The average person can burn that many calories walking a mile or mile and half. If you take your phone and answer emails while walking you’ll get there.

I think most people who are in jobs where they have to answer emails would be better off, physically as well as mentally, by unplugging and learning to be connected to their surroundings, at least for that mile walk.

That's 1.5-3 hours a week of aerobic exercise for most people.

Reminds me of that onion article: "FDA Official: "Just Eat A Goddamn Vegetable""

Having more sex can be a great way to increase the amount of exercise you get and it can be fun too.

My Marilyn Monroebot needs a software patch and new batterpak

As always, correlation / causation might be complicated here. I.e. maybe the sort of conditions that make you more likely to die of a heart attack also wind up reducing your ability / motivation to exercise.

My dad is having heart surgery performed next month. Thankfully it should not be to bad because they managed to catch the issues early on, but these issues were only discovered because my dad is somewhat active and noticed a dramatic decrease in his stamina and then repeatedly insisted to his doctor that he needed to see a cardiologist.

> these issues were only discovered because my dad is somewhat active and noticed a dramatic decrease in his stamina

It can't be overstated how important this aspect of regular physical activity is. The feedback on your body's condition is priceless.

It's like the old adage "it's not a prison if you never try the door". You don't know you're unwell if you never try activities requiring fitness.

100% this. I've posted on HN a few times about my bouts with cancer. I'm only 35 so symptoms were constantly dismissed as something else. Only because I noticed the drop in my workouts did I have the motivation to really push my PCP for more testing. Knowing your body and being an advocate for yourself are so critical in a "if your arm hurts stop moving your arm" medical culture.

It's tough, because odds are your doctor is right. You are an outlier. For the vast majority of people, if you feel OK, you are OK.

> For the vast majority of people, if you feel OK, you are OK.

I think you might be missing the point entirely here.

You can "feel OK" when a whole lot is NOT OK if your daily existence is extremely sedentary and you never even move your joints through their full range of motion, let alone elevate your heart rate and break a proper sweat.

Exercise is literally about exercising your capabilities. If you don't exercise them, you don't discover they've gone missing until it's too late.

The GP didn't feel ok, though. They noticed abnormal negative symptoms compared to previous experiences which their PCP initially ignored. But they only knew that because they got regular physical activity and so could tell the difference.

You correct. If my dad had only relied on the feedback from his doctor he would still be under the impression he was perfectly healthy. Always remember, it is smart to trust modern medicine, not so much to trust any individual practitioner.

Probably the most relevant technical term if you want to look up studies is "exercise intolerance". It seems to be especially well-documented in heart failure patients, but it's also been studied in various chronic conditions.

https://jamanetwork.com/journals/jamacardiology/article-abst...

"This review highlights preclinical evidence that acute exercise-induced cardiac preconditioning has the ability to activate multiple pathways to confer immediate protection against ischemic events, reduce the severity of potentially lethal ischemic myocardiac injury, and act as a physiological first line of defense."

Or simply cardio exercise makes your heart more resilient and efficient.

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