Things they don't tell you about exercise

From Dr Mark Porter today in The Times (emphasis added):

"The real risk [of cardiac arrest] occurs when you push yourself, as can happen in a competitive setting (the squash court) or, as I discovered at the weekend, when hiking up and down the Jurassic Coast with two physically fit daughters.

Older people with “hardened”, furred-up arteries are likely to develop chest pain (angina) if they over-exert, giving them a warning sign that they need to slow down. In advanced cases this can occur on the flat after walking a couple of hundred yards, but with minor narrowings the pain may be evident only 10 to 15 minutes into a cycle ride. If you try to push through the pain, the starved heart muscle beyond the narrowing can trigger a cardiac arrest. Sensible people stop.

More of a concern are silent “soft plaques” that coat the lining of the coronary arteries of otherwise outwardly healthy middle-aged and elderly people. These are like poached eggs covered in a thin crust, and the shearing action caused by the twisting motion the heart adopts when it is beating at very high rates can cause them to rupture, with catastrophic consequences.

The fatty pool (the yolk of the egg) is released into the narrow coronary artery, triggering a clotting reaction that can block blood flow, causing chest pain and starving the muscular heart wall (a heart attack or myocardial infarction). And if you are my age it is often not a matter of if you have some of these plaques, but how many.

This is the rationale behind wearing a pulse-rate monitor and capping your heart rate during exercise as you get older (see the formula below). This is one reason why I am sceptical of the trend for high-intensity workouts that require you to max out on a bike or treadmill in short blasts rather than go for a steady ride or jog for 20 minutes. In my opinion this type of interval training is highly effective but, for the over-50s, best limited to lifelong athletes."

Peta Bee continues:

"while couch potatoes face impending doom in the form of a raised risk of heart disease and diabetes, the aspirationally athletic are encountering their own set of health issues — injuries that threaten to cause long-term harm if left untreated.

Hardcore workouts and high-intensity interval training sessions have contributed to a shift in our perception of what is required to get fit. A survey of more than 4,000 people from across the UK, commissioned by Bupa health clinics, reveals that more than a quarter of gym-goers assume that they have had a good session only if they feel pain during or after it.

Pushing through the pain barrier is taking its toll, with 4.5 million or 43 per cent of people in training for a fitness challenge getting injured in the process; 60 per cent of those who encountered a strain or pulled a muscle or worse never sought treatment and 22 per cent carried on regardless.

...

Lifting weights

Common problem: Haemorrhoids

Prevention

A trend for lifting heavy weights has resulted in an unexpected rise in haemorrhoids, or piles, among gym users. “Weight training is a common cause as people often hold their breath while lifting weights, which forces the air in your lungs downward, putting pressure on your internal organs and the veins in your rectum,” says Dr Amyn Haji, a consultant colorectal surgeon at the Whiteley Clinic in London. “As a result, the veins near your anus become swollen and are forced outside the body, which can cause uncomfortable and sometimes painful haemorrhoids.”

Treatment

In some cases haemorrhoids disappear within a few days. “However, I’d recommend seeing a qualified personal trainer to help you perfect your breathing technique while weight training,” Haji says. “To prevent it from worsening, avoid weight lifting if you have already developed the condition, drink plenty of fluids and buy some over-the-counter medicines — there’s a variety of creams, lotions and gels available to treat the problem.”

I had to stop weight training at the beginning of August as I was experiencing pain in my elbow joints (both arms) and in my forearm tendons. You know it's bad when you have problems lifting a mug of coffee, or using the loppers in the garden (yesterday).

Happier days. I started home weight-training in September 2016 - (link)

It's now November 2017, and the last three months have resulted in essentially no improvement, despite my having ceased lifting. I self-diagnosed as RSI and expect a long period of slow recovery. I was lifting at ridiculous levels for someone with no real history: squats at 28 kg, biceps curls at 23 kg. Idiotic at age 66.

The gag is on

Walking down to Waitrose this morning - and dragging the new sholley, my weight-training-induced sore forearms still haven't gone away and it's 'no more Mr Heavy-Shopping-Bags' - I ventured this thought to Clare.

"Shall I tell you the new thing I've learned today?"

Grudging acquiescence.

"You know I'm continually fascinated by the way AI and robotics are going to transform capitalism, and how exactly that transformation's going to work ..."

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The new thing was from Part 2 of Michael Roberts' insightful series, 'Robots and AI: utopia or dystopia?' ..

"The question often posed at this point is: who are the owners of the robots and their products and services going to sell to make a profit?  If workers are not working and receiving no income, then surely there is massive overproduction and underconsumption?  So, in the last analysis, it is the underconsumption of the masses that brings capitalism down?

"Again, I think this is a misunderstanding.  Such a robot economy is not capitalist any more; it is more like a slave economy.  The owners of the means of production (robots) now have a super-abundant economy of things and services at zero cost (robots making robots making robots).  The owners can just consume.  They don’t need to make ‘a profit’, just as the aristocrat slave owners in Rome just consumed and did not run businesses to make a profit.

"This does not deliver an overproduction crisis in the capitalist sense (relative to profit) nor ‘underconsumption’ (lack of purchasing power or effective demand for goods on a market), except in the physical sense of poverty. ..."

Roberts here puts his finger on the key mode of production change required by total automation: production of exchange-values collapses and all production is of use-values, just like in slave-owning antiquity.

The issue is, who gets to be the recipient of such wonders of production, the owners of the robots .. or everyone? It seems contentious.

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Where to start? The only place was the labour theory of value.

"So Marx said that the capitalist pays the worker the value of his labour-power - what it costs to maintain the worker as an effective employee - and sets him to work. But the value the worker actually creates in his day's labour is more than this, and that value belongs to the capitalist, creating his profit once realised in the exchange process.

"But if the worker is replaced by a robot ..."

But Clare was having none of this.

"That can't be right. If the worker is paid less than what he produces, then the employer won't be able to sell all his products. No, Marx was quite wrong."

I hesitatingly began to talk about Marx's simple and expanded reproduction equations, Departments I and II .. but the audience had switched off.

In truth, I don't think the objection can be addressed in ordinary conversation, the sources of demand being manyfold: in addition to the needs of proletarians you will find capitalists' spending on themselves, the market for reproduction and expansion of the means of production .. .

No less a luminary than Rosa Luxemburg got it wrong.

In fact I explained quite clearly both simple reproduction and expanded reproduction within capitalism on this blog, but if you review the two posts you will see the analysis is not wholly trivial.

This afternoon I considered going through the spreadsheets with her - and decided against having my arm bitten off.

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You may have heard over the last couple of days: Mathematicians Measure Infinities and Find They’re Equal.

It relates to whether there are cardinal numbers between the infinity representing the size of the natural numbers and the larger infinity capturing the size of the real numbers. The continuum hypothesis says no, but that can't be proven using the normal axioms of set theory.

The work of Malliaris and Shelah has some bearing on the matter although not all is completely clear (is the cardinality of p = t the same as the continuum?).

I said to Clare, "Did you know there are different sizes of infinity?"

She snorted, "That kind of nonsense is just what gives mathematics a bad name."

I advanced on her with paper and pen; she sat back on the couch, closed her eyes, put her hands over her ears and started to hum.