exercise good for you - large study

[Carlton green]

Trouble with cycling is its to efficient one has to do loads.
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I ride Brompton and a 100% British Vintage

That made me laugh, I’ve got inbuilt extra weight (a load, BMI in the overweight range). My Dog acts as my personal trainer too, he regularly gets on my bike and is an extra load. Stick a few large bottles of water in your panniers and the extra load will add to the exercise.

Later I laughed again as I realised that I’d confused loads meaning lots with loads meaning weight.

Cycling is variable in its efficiency. My most used bike has a three speed hub gear; I’m very happy with my SA AW - it has its advantages - but I feel sure that there are gearing arrangements that would typically be less tiring to use. Brucey used to train using SA AW’s, and I anticipate that he later flew along on derailleur gears.

I'd also assume that too much exercise is bad for you (to some extent at least) - just from a wear and tear point of view.
Probably outweighed for the vast majority of people by the positive benefits though.

I’m fairly sure that too much exercise does wear folk out, folk who do manual job’s don’t always have good health or live to a ripe old age. There’s surely a balance point and of course, though some ignore it, high intensity and high load activities can but use our bodies in ways that they were never intended to support. I’m no expert but have picked up injuries and simply got tired out from over exertion; injuries stopped further exercise for some time and it can take a couple of days to recover from being tired out. Moderation - what ever that is - seems best.

[Pebble]

I have just recently had some lung tests, spirometry I think, apparently my results were 40 & 50% higher than what would be expected of someone my age - the doctor put this down to my cycling and banged on about how good cycling is and how fit I am. of course he would say that, he is also a keen cyclist, so no doubt justifying his own hobby.

I didn't believe any of it though, I'm convinced my lungs are shot, a life time of abuse from asbestos diesel fumes and heavy smoking, are clearly the cause of the sharp pains I get between my ribs, and are a sure sign of their demise. Doctors and their tests, what do they know!

[axel_knutt]

The revalation here is not just the exercise its how little you actually need to produce a beneficial result.

Not that much of a revelation, Arem and Gebel were publishing this law of diminishing returns 8 years ago

Most regular cyclists will be getting far more, I wonder what that does?

At best there's no benefit, at worst it increases your risk of arrhythmia and other conditions.

I always find the MET a confusing unit, and the mMET doubly so, so am unsure how to turn this all into something meaningful in terms of cycling hours ….. when doing the calculations should I be subtracting “subsistence power” from the average power output during cycling, which yields depressing results, or should I simply use the average power during cycling, which gives quite heartening(!) results?

The MET is just your power consumption normalised to your bodyweight, in kcal/hour/kg. If you want to know your energy consumption, the ACSM Compendium of Physical Activity lists the metabolic rate for a total of 822 activites, the majority of which (inlcuding the ones that interest people on here) are actual measured data published in peer reviewed papers. It includes just about every activity you care to think of, from running, cycling, walking, swimming etc, to washing the pots, watching TV, and even having sex.

The data as tabulated are population averages, if you want to improve the accuracy further you can adjust the figures to compensate for your own individual age, weight, height and sex.

Marginal METs are the energy consumption over and above that used by sedentary behaviour.

"To marginalise studies reporting volume of PA in gross units, 1 MET-hour was subtracted for each hour of activity."

"Including low-intensity high-duration activities such as occupational activity without marginalising the resting component can therefore distort the PA exposure dramatically."

I reckon that the mental benefits rack-up far beyond that though.

They did for me, but at a very high price: I ruined my health, and can now do nothing but sit in the chair without making it worse, which is not very good for my mental or physical health.

This is the exercise distribution in Garcias cohort, with my exercise level marked on it (red line):

Extrapolating Fig 4, perhaps it's not so surprising I got a rectal tumour, along with a heart arrhythmia:

[Nearholmer]

Commiserations. That is (was) when heck of a lot of exercise.

Thank you. I’m still not sure I’m totally convinced, because I’m not totally convinced that going for a bike ride is, say, ten times more demanding than sitting in an armchair doing nothing, and I’m especially not at all convinced that DIY activities use only about half the energy of cycling, when to me they seem at least twice as demanding, but I’ll go with it.

[simonineaston]

Yes. It's a pretty consistent finding. And a very important message both for individuals and public health policy.

I think the hidden message is how many folk don't get even make that low, low base line. I dunno - I'm only guessing. I remember my best friend's mum, who lived next door but one from us, back when... she barely left her house other than to go up to the shops in her car a couple of times a week.

[Jdsk]

Yes. It's a pretty consistent finding. And a very important message both for individuals and public health policy.

I think the hidden message is how many folk don't get even make that low, low base line. I dunno - I'm only guessing. I remember my best friend's mum, who lived next door but one from us, back when... she barely left her house other than to go up to the shops in her car a couple of times a week.

Yes. And making that change to a small amount of exercise is difficult. And keeping it going is difficult.

Knowing that it makes a difference is important to both the patient and the practitioner.

Jonathan

PS: The lead researcher who demonstrated the link between smoking and lung cancer was particularly proud of going on to show that stopping smoking decreased the risk.

[mattheus]

They did for me, but at a very high price: I ruined my health, and can now do nothing but sit in the chair without making it worse, which is not very good for my mental or physical health.

This is the exercise distribution in Garcias cohort, with my exercise level marked on it (red line):
2022 Garcia Fig 1 Exercise Distribution.png

Extrapolating Fig 4, perhaps it's not so surprising I got a rectal tumour, along with a heart arrhythmia:
Garcia Fig 4 Rectal.png

I can't easily digest all this jargon :-/ And I can't read your graph ... but I looked at the source page. Still not sure:

Are you saying you did approx 90h/week of "typical" exercise above the sedentary adult? Or exercise equivalent to ... err dunno ... something ...

[pwa]

Cycling, even more than walking, is only really a decent workout if you are actually putting some physical effort into it for some of the time. pootling along with minimal effort, even if for a couple of hours, is low grade exercise. Just like a slow walk. Or a spot of gardening.

And the beneficial effects of exercise can be undone by poor diet. I have had very active friends who have succumbed to heart disease and strokes over the years. So I never assume my cycling is a magic cloak protecting me from ill-health.

Ironically, perhaps, I recently watched a delivery van person scurrying up and down driveways as he delivered small parcels, and it occurred to me that over the course of a shift he must do quite a lot of brisk exercise in very small doses.

[simonineaston]

I've repeated this anecdote to the point of tedium I'm afraid, however here it comes again...
I used to work alongside a consultant anaesthetist who cycled to work on a 3 speed shopper, "Why the cheap bike, Tony?" I asked one day, to which he replied, "I wouldn't get much exercise on a good one.".

[horizon]

folk who do manual jobs don’t always have good health or live to a ripe old age.

AIUI (from studies) is that the form of exertion that prolongs life is cardio-vascular (the "strong legs" syndrome). Hard manual works builds muscles but can deplete the body - moderation wasn't always (if ever) possible for a person doing such work. Nowadays they suffer from the opposite problem - sedentary sitting, driving and computing. We still need the heavy lifting but I would put cardio (IMV) as above that.

[Carlton green]

folk who do manual jobs don’t always have good health or live to a ripe old age.

AIUI (from studies) is that the form of exertion that prolongs life is cardio-vascular (the "strong legs" syndrome). Hard manual works builds muscles but can deplete the body - moderation wasn't always (if ever) possible for a person doing such work. Nowadays they suffer from the opposite problem - sedentary sitting, driving and computing. We still need the heavy lifting but I would put cardio (IMV) as above that.

Heavy lifting, I mostly avoid that and try to take care when I need to lift heavy stuff. It’s not that hard to upset you back, pull a muscle or somehow injure yourself by pushing yourself too near to the limits of what you can do. I’ve become a believer in moving lighter weights many times rather than heavy weights a few times, works for me.

To my mind caridio-vascular is the way to go but in moderation, the idea is to improve or retain fitness whilst avoiding exhaustion and injury, seeking out a happy medium. I don’t need to be super fit but I do need a level of fitness that gets me well away from the danger areas that are associated with a sedentary life style; cycling, dog walking and gardening seem to be providing many hours of the necessary exercise.

I've repeated this anecdote to the point of tedium I'm afraid, however here it comes again...
I used to work alongside a consultant anaesthetist who cycled to work on a 3 speed shopper, "Why the cheap bike, Tony?" I asked one day, to which he replied, "I wouldn't get much exercise on a good one.".

I can sort of relate to that level of exercise and efficiency, but on the other hand he had a functional bike that supplied both exercise and transport. Three speeds does make it more of a workout and then small wheels too ; I anticipate that he didn’t worry about anyone nicking his bike . To be fair though those old shoppers get a lot of stick but as a handy bike for local use they’re underrated; I’d have one for such local use and whatever else I could reasonably manage to get it to do.

[axel_knutt]

There's an online calculator here to go with this paper, which you can play with to your hearts content.

I’m not totally convinced that going for a bike ride is, say, ten times more demanding than sitting in an armchair doing nothing

At what speed? Cycling at 12mph (7.4MET) is 5.7 times Watching TV (1.3MET).

Are you saying you did approx 90h/week of "typical" exercise above the sedentary adult? Or exercise equivalent to ... err dunno ... something ...

No, that's not what I'm saying, the graph is calibrated in marginal MET hours per week, not hours.

So if we take cycling at 12mph as an example, that's 7.4METs, sedentary is 1MET, so the marginal power (the additional power over and above being sedentary) is 6.4METs. If you then cycle for an hour and a half at that speed that's 1.5 x 6.4 = 9.6 marginal MET hours, and if you did that twice a week that would be 19.2 mMEThr/week on the graph.

Here's the graph for all-cause mortality, I've added a second scale to the graph (in red) that reads in terms of weekly cycle mileage, assuming an average speed of 12mph. (I've used round numbers, 10mMEThr/wk is actually nearer 19m).
I have also extended the scale to fit on my own data. The 46 figure is the average of 20 years from 1992 - 2011 incl., and the 92 figure is the average for 2009, which was the highest single year. (It's actually a combination of walking, cycling and swimming, not all cycling.)

Note that the dark shaded area is the portion for which the data is reliable (the lowest 75% of person-years), and the dotted line is just a linear extrapolation based on the assumption that it follows the same slope as that at the 75th centile. Who knows what happens to it beyond the question mark!

[bikes4two]

• Heck, this post is one of those that needs a clear head to get into so I'll leave the heavy thinking to a bit later on.

• And actually I'm not that fussed whether cycling is good or bad for me as I just like cycling what ever the effects are (but nice to know it's mainly positive).

• As it happens too much cycling brings on my Atrial Fibrillation but what the hell, I just have to cycle and that's that!

[Carlton green]

With some posters talking about injury and reduced health, and with observed anecdotal experience, I do wonder if there are any studies on amounts of exercise that are bad for you? Of course we’re all a bit different, and we change over time too, but it’s easier than we might think to ‘do yourself a mischief’ - Andrew Marr is one famous example of such https://www.bbc.co.uk/news/av/uk-22142291.

There are optimum amounts for pretty much everything. Apparently taking an aspirin a day can be good for your health, so taking two should be twice as good? ‘Logically’ taking a bottle of them should be excellent, but it certainly is not: it’s an overdose and it can be fatal.
https://www.nhs.uk/medicines/low-dose-a ... e-aspirin/

Moderation in all things seems wise, but for each activity what lies within the moderate range?

[Jdsk]

With some posters talking about injury and reduced health, and with observed anecdotal experience, I do wonder if there are any studies on amounts of exercise that are bad for you? Of course we’re all a bit different, and we change over time too, but it’s easier than we might think to ‘do yourself a mischief’ - Andrew Marr is one famous example of such https://www.bbc.co.uk/news/av/uk-22142291.

There are optimum amounts for pretty much everything. Apparently taking an aspirin a day can be good for your health, so taking two should be twice as good? ‘Logically’ taking a bottle of them should be excellent, but it certainly is not: it’s an overdose and it can be fatal.
https://www.nhs.uk/medicines/low-dose-a ... e-aspirin/

Moderation in all things seems wise, but for each activity what lies within the moderate range?

There are plenty of studies documenting injury rates from exercise.

But it's hard to think of a subject where the consensus on benefits is so strong. It's a little harder to discuss it in this forum because there are some people who exercise very hard.

Jonathan

PS: Moderation in all things isn't wise. Following the evidence is much smarter.

PPS: Marr's description of the advice that he was getting isn't what experts were recommending at the time.