Age Limits On Exercise?

In Tuesday’s newsletter, we asked you your opinion on whether we should exercise less as we get older, and got the above-depicted, below-described, set of responses:

• About 42% said “No, we must keep pushing ourselves, to keep our youth“
• About 29% said “Only to the extent necessary due to chronic conditions etc”
• About 29% said “Yes, we should keep gently moving but otherwise take it easier”

One subscriber who voted for “No, we must keep pushing ourselves, to keep our youth“ wrote to add:

❝I’m 71 and I push myself. I’m not as fast or strong as I used to be but, I feel great when I push myself instead of going through the motions. I listen to my body!❞

~ 10almonds subscriber

One subscriber who voted for “Only to the extent necessary due to chronic conditions etc” wrote to add:

❝It’s never too late to get stronger. Important to keep your strength and balance. I am a Silver Sneakers instructor and I see first hand how helpful regular exercise is for seniors.❞

~ 10almonds subscriber

One subscriber who voted to say “Yes, we should keep gently moving but otherwise take it easier” wrote to add:

❝Keep moving but be considerate and respectful of your aging body. It’s a time to find balance in life and not put yourself into a positon to damage youself by competing with decades younger folks (unless you want to) – it will take much longer to bounce back.❞

~ 10almonds subscriber

These will be important, because we’ll come back to them at the end.

So what does the science say?

Endurance exercise is for young people only: True or False?

False! With proper training, age is no barrier to serious endurance exercise.

Here’s a study that looked at marathon-runners of various ages, and found that…

• the majority of middle-aged and elderly athletes have training histories of less than seven years of running
• there are virtually no relevant running time differences (p<0.01) per age in marathon finishers from 20 to 55 years
• after 55 years, running times did increase on average, but not consistently (i.e. there were still older runners with comparable times to the younger age bracket)

See: Performance, training and lifestyle parameters of marathon runners aged 20–80 years: results of the PACE-study

The researchers took this as evidence of aging being indeed a biological process that can be sped up or slowed down by various lifestyle factors.

See also:

Age & Aging: What Can (And Can’t) We Do About It?

this covers the many aspects of biological aging (it’s not one number, but many!) and how our various different biological ages are often not in sync with each other, and how we can optimize each of them that can be optimized

Resistance training is for young people only: True or False?

False! In fact, it’s not only possible for older people, but is also associated with a reduction in all-cause mortality.

Specifically, those who reported strength-training at least once per week enjoyed longer lives than those who did not.

You may be thinking “is this just the horse-riding thing again, where correlation is not causation and it’s just that healthier people (for other reasons) were able to do strength-training more, rather than the other way around?“

…which is a good think to think of, so well-spotted if you were thinking that!

But in this case no; the benefits remained when other things were controlled for:

❝Adjusted for demographic variables, health behaviors and health conditions, a statistically significant effect on mortality remained.

Although the effects on cardiac and cancer mortality were no longer statistically significant, the data still pointed to a benefit.

Importantly, after the physical activity level was controlled for, people who reported strength exercises appeared to see a greater mortality benefit than those who reported physical activity alone.❞

~ Dr. Jennifer Kraschnewski

See the study: Is strength training associated with mortality benefits? A 15 year cohort study of US older adults

And a pop-sci article about it: Strength training helps older adults live longer

Closing thoughts

As it happens… All three of the subscribers we quoted all had excellent points!

Because in this case it’s less a matter of “should”, and more a selection of options:

• We (most of us, at least) can gain/regain/maintain the kind of strength and fitness associated with much younger people, and we need not be afraid of exercising accordingly (assuming having worked up to such, not just going straight from couch to marathon, say).
• We must nevertheless be mindful of chronic conditions or even passing illnesses/injuries, but that goes for people of any age
• We also can’t argue against a “safety first” cautious approach to exercise. After all, sure, maybe we can run marathons at any age, but that doesn’t mean we have to. And sure, maybe we can train to lift heavy weights, but if we’re content to be able to carry the groceries or perhaps take our partner’s weight in the dance hall (or the bedroom!), then (if we’re also at least maintaining our bones and muscles at a healthy level) that’s good enough already.

Which prompts the question, what do you want to be able to do, now and years from now? What’s important to you?

For inspiration, check out: Train For The Event Of Your Life!

Take care!

The Pathogens That Came In From The Cold

Yesterday, we asked you about your climate-themed policy for avoiding respiratory infections, and got the above-depicted, below-described, set of answers:

• About 46% of respondents said “Temperature has no bearing on infection risk”
• About 31% of respondents said “It’s important to get plenty of cold, fresh air, as this kills/inactivates pathogens”
• About 22% of respondents said “It’s important to stay warm to avoid getting colds, flu, etc”

Some gave rationales, including…

For “stay warm”:

❝Childhood lessons❞

For “get cold, fresh air”:

❝I just feel that it’s healthy to get fresh air daily. Whether it kills germs, I don’t know❞

For “temperature has no bearing”:

❝If climate issue affected respiratory infections, would people in the tropics suffer more than those in colder climates? Pollutants may affect respiratory infections, but I doubt just temperature would do so.❞

So, what does the science say?

It’s important to stay warm to avoid getting colds, flu, etc: True or False?

False, simply. Cold weather does increase the infection risk, but for reasons that a hat and scarf won’t protect you from. More on this later, but for now, let’s lay to rest the idea that bodily chilling will promote infection by cold, flu, etc.

In a small-ish but statistically significant study (n=180), it was found that…

❝There was no evidence that chilling caused any acute change in symptom scores❞

Read more: Acute cooling of the feet and the onset of common cold symptoms

Note: they do mention in their conclusion that chilling the feet “causes the onset of cold symptoms in about 10% of subjects who are chilled”, but the data does not support that conclusion, and the only clear indicator is that people who are more prone to colds generally, were more prone to getting a cold after a cold water footbath.

In other words, people who were more prone to colds remained more prone to colds, just the same.

It’s important to get plenty of cold, fresh air, as this kills/inactivates pathogens: True or False?

Broadly False, though most pathogens do have an optimal operating temperature that (for obvious reasons) is around normal human body temperature.

However, given that they don’t generally have to survive outside of a host body for long to get passed on, the fact that the pathogens may be a little sluggish in the great outdoors will not change the fact that they will be delighted by the climate in your respiratory tract as soon as you get back into the warm.

With regard to the cold air not being a reliable killer/inactivator of pathogens, we call to the witness stand…

Polar Bear Dies From Bird Flu As H5N1 Spreads Across Globe

(it was found near Utqiagvik, one of the northernmost communities in Alaska)

Because pathogens like human body temperature, raising the body temperature is a way to kill/inactivate them: True or False?

True! Unfortunately, it’s also a way to kill us. Because we, too, cannot survive for long above our normal body temperature.

So, for example, bundling up warmly and cranking up the heating won’t necessarily help, because:

• if the temperature is comfortable for you, it’s comfortable for the pathogen
• if the temperature is dangerous to the pathogen, it’s dangerous to you too

This is why the fever response evolved, and/but why many people with fevers die anyway. It’s the body’s way of playing chicken with the pathogen, challenging “guess which of us can survive this for longer!”

Temperature has no bearing on infection risk: True or False?

True and/or False, circumstantially. This one’s a little complex, but let’s break it down to the essentials.

• Temperature has no direct effect, for the reasons we outlined above
• Temperature is often related to humidity, which does have an effect
• Temperature does tend to influence human behavior (more time spent in open spaces with good ventilation vs more time spent in closed quarters with poor ventilation and/or recycled air), which has an obvious effect on transmission rates

The first one we covered, and the third one is self-evident, so let’s look at the second one:

Temperature is often related to humidity, which does have an effect

When the environmental temperature is warmer, water droplets in the air will tend to be bigger, and thus drop to the ground much more quickly.

When the environmental temperature is colder, water droplets in the air will tend to be smaller, and thus stay in the air for longer (along with any pathogens those water droplets may be carrying).

Some papers on the impact of this:

• Cold temperature and low humidity are associated with increased occurrence of respiratory tract infections
• A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate

So whatever temperature you like to keep your environment, humidity is a protective factor against respiratory infections, and dry air is a risk factor.

So, for example:

• If the weather doesn’t suit having good ventilation, a humidifier is a good option
• Being in an airplane is one of the worst places to be for this, outside of a hospital

Don’t have a humidifier? Here’s an example product on Amazon, but by all means shop around.

A crock pot with hot water in and the lid off is also a very workable workaround too

Take care!