What exactly causes the stereotypical slow and inflexible movements in older people? is it a loss of muscle tissue, bone weakening, joint and tendon problems, a combo, or other factors? Can someone in their 60s who practices regular aerobics, yoga (or other stretching exercises) and weight training have the flexibility and motion of someone in their 20s or 30s? Can lack of mobility be reversed after it develops or is it largely irreversible by that point?
Younger people sucking the life out of us.
I don’t know about others. I have general arthritis making me stiff. My balance isn’t very good any more. I don’t see all that well in dim light.
We do it just to annoy you youngins. We drive slow too. Do you think our cars have arthritis too? <toothless grin>
Yes and yes, qualifiedly. I’m 66 (almost 67) and do yoga-type stretching exercises every morning, along with the standard sit-ups, push-ups, and chin-ups. I do weight training at the gym every other day. I run, swim, bike, and play tennis. I’m not as flexible as many others, especially those in their 20s and 30s, but I never was very flexible. I’m probably as flexible now as I was then. I’m stronger and leaner now than I was then. Stretching exercises can make one more flexible, but only to a degree. Now, I’m talking about flexibility. I don’t know what you mean by mobility. If one does not have a physical impediment, there’s no reason one will lose his or her mobility. Speed, however, will diminish. I’m nowhere near as fast as I used to be. My 10-K times have slowed from the 38s to near 50. My marathon times have slowed from around 3:10 to 5:30 (the last one I ran a couple of years ago, and probably slower now if I were to once again train for one).
The reason one slows down remains a mystery to me. If one has a good explanation for this, I’d like to hear it. I don’t think it’s flexibility, as noted above. Perhaps the loss of fast-twitch muscles? Certain changes take place as one ages, but those changes can be kept at a minimum if one works at it. What changes occur that slows one’s speed?
Some older people look stooped-over (scoliosis or kyphosis), but this is due to spinal disorders and does not happen to everyone who ages. I remember my gym teacher in high school saying that happens to people who do not maintain good posture. Now, I know better. It’s a physical degeneration that occurs due to dehydration of the spinal discs and the nucleius pulposi or to osteoporosis.
I’m 57 and I hate you.
Geez! People who know me hate me, and now even people who don’t, hate me.
That just means you’ve finally hit the big time! Lean into it.
There have been studies which indicate that things like yoga and tai chi improve the flexiability and balance of older folks. As for why we slow down when we get older, it’s probably a combination of physical/psychological factors. As we age, it takes longer for us to heal from injuries than when we were younger, so a minor sprain which might inconvience us for a couple of days when we’re a teenager, lays us up for a week or more when we get older. With experience, a lot of the novelty wears off many things in life, so doing things becomes less exciting, so we become disinclined to move about, and if you don’t use your muscles, you lose them.
I wouldn’t say I hate anybody, but I’m 40 (starting today as it turns out) and I’m awfully jealous.
I break a sweat just driving 10K.
Injuries take longer to heal, but that’s not a factor in slowing down. (In fact, I avulsed my right Achilles’ tendon last October, but I was running and playing tennis in February, much to the amazement of my orthopedist, who called me his “amazing patient.”) Psychological factors? I still train just as hard, only slower. A combination of physiological factors, no doubt. Just what are they?
Now that I’m through patting myself on the back, to answer the OP, those things that he notices in older people are not inevitable, but if you become a couch potato, more likely. Some factors you have no control over, such as injuries (but those you really could have avoided in most cases), cancer, osteoarthritis, rheumatoid arthritis, etc. My running buddy (who just had his 72d birthdate) has recently been diagnosed with peripheral neuropathy, affecting his feet. The etiology is unknown, perhaps hereditary. (He doesn’t drink nor does he have diabetes.) That has slowed him down considerably, but we still run together on Mondays and Fridays, albeit at a much slower pace than we used to.
I don’t have a cite for this exactly but i vaguely* remember something from either TLC or Discovery. Basically it was just part of the aging cycle. The DNA of the cells breaks down over the decades by something called a free radical (i think that’s what they called it?) The free radicals hit part of the strand and the DNA isn’t as “pure” as it used to be. And it’s the gradual break down all over the body that causes aging and it’s “side effects” so to speak. Things like vision, skin, muscles, flexibily, etc are all just a part of the aging process that kills us all.
*it’s been about 5 years or so, so take this with a grain of salt at least
When I hijacked this thread and asked that question, I did not recall reading about it, but after I posted and after I wrote about fast-twitch muscles, my aging and feeble mind recalled reading an article a few years ago on exactly this topic. Actual studies and biopsies were done on muscles of runners, and it was concluded that the fast-twitch muscles do degenerate in time, becoming more similar to slow-twitch muscles.
Boy, you know I’m 25 and I have to admit that I’m awfully jealous as well. 
I read a few years ago that the cardiovascular system simply becomes less effective/efficient at extracting oxygen. VO2 max goes way down, meaning the ability to transport and utilize oxygen decreases markedly. I’ve also read that there is no way to counter this process, although it can be slowed, through training. The general theme was that folks can still do endurance events, but their times inexorably slow. And while I won’t argue with that deterministic model, the same thing used to be said about the inability to change VO2 max.
That’s correct, Carnac the Magnificent!. I’d forgot about that. Then it’s a combination of the decrease in VO2 and degradation of the fast twitch muscles.
One important cause is something called Advanced Glycosylation End-product (appropriately acronymed AGE) crosslinks. As I understand it, your typical protein in the body has a number of sugar molecules attached to them. This is normal and indeed required for the protein to do its job. But when one protein attaches itself to the sugar of another protein, you get what’s called an AGE crosslink. These accumulate as you get older and the more a given tissue has, the stiffer it is.
There is a drug named Alagebrium that will break AGE crosslinks, but I believe it’s still in trials. It’s made by a company called Alteon and is also known by its code name ALT-711. I understand that ALT-711 will also remove scar tissue and calluses and makes skin very soft.
Some of the stiffness (and possibly some of the cardiovascular consequences) of aging may be due to accumulation of chemically modified proteins (and DNA) in the body.
The classic example occurs with glucose which non-enzymatically, and irreversibly, bonds (randomly) to amino groups of proteins. This phenomenon underlies the use of the hemoglobin A1 test diabetes (where the glucose has bonded to the amino groups of hemoglobin).
In any case, when glucose binds to proteins the effect is to invariably alter their function for the worse. In the case of collagen (found in skin and bone and the lining of blood vessels), glycated-collagen is formed and it is weaker and less flexible than the unaltered protein.
Since all of us have glucose in our blood (not just diabetics), all of us will form these glucose-protein compounds. The longer we go on, the more of them we form. If we have high blood sugar, we form even more.
A nasty epiphenomenon occurs when one glucose-protein cross links with another, i.e. protein-glucose + glucose-protein ==> protein-glucose-protein. The sequence repeats and you wind up with large “networks” of the stuff (which resists degradation). Ultimately, large quantities of these advanced glycation end-products accumulate. Note the natural acronym: AGE’s
In addition to direct “gumming up” effects, these AGE’s can also elicit an immune response as well as acting as signals for various scavenger and blood vessel wall cells to do destructive things.
Here is one link: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11976210
Unfortunately, most of the web pages on the net about this seem to be from commercial sites and are useless.
dtilque: Sorry, didn’t see your post. It came while I was composing mine.