canklecat

And to show that I'm willing to try anything reasonable (excluding drinking or injecting Lysol, bleach or UV light), I've grilled a couple of friends about their radical diet changes over the past decade.

Both men have gone all in on the carnivore/keto diets, long before the recent keto fad. Both are close to my age (late 50s). Both have incisive logical minds (one is more analytical and skeptical, the other tends to lean a bit toward some pop-culture health articles and trends but never goes full woo). Both report significant improvements in health, loss of weight, and relief from nagging but non-serious health issues. Neither has the same endocrine or auto-immune disorder I have, so I'm not expecting identical results.

But I have been gradually eliminating or reducing certain foods, as I try them one by one to check for reactions, and generally increasing my intake of meats, reducing carbs and sugars and eliminating alcohol. I've cut out anything that seems to aggravate various allergic reactions -- sinus congestion, swollen eyes, skin rashes, etc. Without testing, there's a lot of guesswork. My immunologist plans to run some tests soon to try to determine what, specifically, I'm allergic too. I usually say I'm allergic to Texas.

I generally consume carbs only in conjunction with workouts, and even then try to limit intake to what I'll burn during a long ride or workout. Generally I can maintain a tempo pace (for me, which is much slower than tempo pace for younger folks) for 90-120 minutes before I feel the need to replenish so I'll carry a couple of gels, maybe a Clif bar or something similar. At a much reduced effort I can ride pretty much all day without eating, as long as I drink enough water. But I carry a couple of gels anyway, especially now since I want to reduce any need to visit a convenience store for emergency carbs and drinks.

Carbonfiberboy 

See #23 . I'm very interested in choice theory: our happiness in life may be largely determined by the choices we make, choices for which we will not know the results for 20 or 30 years. As Mother Nature once said, "There are three things you can do: you can do good, you can do bad, or you can do nothing." Teddy Roosevelt put it a little differently: "In any moment of decision, the best thing you can do is the right thing, the next best thing is the wrong thing, and the worst thing you can do is nothing."

sirjag

Pretty much the same. Here in Austin area summers, I drink 5lbs of water in about 3hrs of riding, and I still lose close to 5lbs when i get back...so a net loss of 10 lbs each summer ride...

JAG

wphamilton

I don't mind admitting that I have a knowledge gap keeping me from fully understanding it. I have questions but googling them up raises more questions.

For a "sniff check" we have 5 liters of blood with 10 mg/dL of calcium, and sweat out 20 mg/hr under profuse sweating. My calculator says that it comes to .04 percent per hour, from our blood. And blood has only 1 percent of our calcium. So the calcium loss is .000004/hr of the total.

Although I see references to a much higher loss of calcium than that 20 mg/hr, it's still hard to see how that level of loss can decrease bone mass meaningfully. Unless there is something chemical going on that somehow amplifies the effect? (That's where I fall short, having no idea if that's the case or even plausible)

Carbonfiberboy 

Please reread the first sentence of the OP in which I agree with you. Then read the studies. I might be able to tell you in a couple more years, when I get my next DEXA, whether or not taking calcium before rides worked.

wphamilton

Are you saying that the studies answer my questions? You may have to elaborate then because I did read them fairly closely, and that's where the questions started. For example it seems to me to neglect other half of homeostatic balance - not neglect precisely because they mention it, but don't address it. That's one reason that I'm skeptical that your conclusion (about the homeostatic balance) is strongly justified by that particular study.

Carbonfiberboy 

I'm not on earth to convince you of anything. You pays your money, you takes your choice. My reading is that long, hard, and sweaty aerobic exercise upsets the bone gain/loss balance. You can google "tour de france riders spine bone loss", read the resulting articles and studies and decide what you want to believe and how you want to proceed. I'm osteoporotic, possibly from training continuously for the past 25 years. I've never broken a bone except for a couple ribs from a skiing fall while doing 40 through moguls when I was 20. I've had a zillion skiing falls - I still ski hard (if you're not falling, your not learning), and a few cycling falls. I'm pretty good at falling. It's also possible that well conditioned and powerful musculature might protect against fractures, IDK.

Meanwhile, waiting for either death or confirmation of these studies, I'm taking 2 $.08 calcium tabs before sweaty rides and a couple magnesium tabs later in the day to balance them. I've also started drinking milk. My electronic scale says my bone mass has gone up, but what does it know.

I think I'll take that calcium now. I'm supposed to do an FTP test in an hour. My legs still hurt pretty good from Sunday/Monday, but I'll see how that goes.

wphamilton

Calcium supplements are at least well established to improve bone density.

As for your relatively obnoxious first paragraph, I didn't realize that you posted this thread with such a stretch conclusion just for us all to accept without question. Since you position it as "believe what you want to believe" I'll not press you further for a factual foundation.

Carbonfiberboy 

Belief is an ever-present danger. The point of science is to disprove current knowledge if possible.

I posted information. These are the first studies I've seen which may offer a method of reducing bone loss in endurance athletes. My interest was piqued because ironically, the relationship you suppose has not been established, see: https://pdfs.semanticscholar.org/07d...f5bc4b9a35.pdf
One has to read the whole study to understand the conclusion. A further irony is that this study conclusion ends with:and AFAIK there are no such treatments, bisphosphonate having been found to cause bones to become brittle even though bone mass is increased as shown by DEXA scans. This study found treated bone to have poorer mechanical properties than untreated osteoporotic bone: https://pdfs.semanticscholar.org/07d...f5bc4b9a35.pdf I was prescribed bisphosphonate treatment, but stopped it about a year ago, after one year, for the above reason. My rheumatologist intended for me to take it for many years.

wphamilton

That particular study isn't difficult to grasp - but before you could even begin to suppose that sweating from exercise is the major cause of bone density loss you have to look into both the effect and trigger of the PTH hormone. Because there simply isn't enough secreted to account for the changes in homeostatic balance. And yet when you do take a deep dive into that hormone, things are much less clear than you seem to believe. Given the"goggle ultra-cycling" type responses. I don't think we're even in the same conversation, so I'm going to leave you to it.

Carbonfiberboy 

Quite right. It's another case of "see post 23". You might want to contact the corresponding author, Daniel Barry with your concerns. My response follows the study's suggestion: This study has been cited by 17 others. You might want to look into some of these also: https://www.ncbi.nlm.nih.gov/pmc/art...45631/citedby/

I don't quite understand what your problem is. I didn't come here to defend my PhD thesis. I'm just posting what I feel is useful information which just might help someone.

canklecat

As Carbonfiberboy said above, ask me in a year whether my approach (and that recommended by my doctors) results in any measurable improvements in bone density and related vitamin D level.

My docs have been urging me for a couple of years to take the vitamin D and calcium supplements the VA sends me. I usually didn't. I figured I already take a multi-vitamin and eat a pretty good diet.

But I still have osteopenia and my vitamin D level is very low.

I told my docs I was doubtful about the test results. I said that, with the exception of bones broken by extreme situations -- being hit by cars twice -- I had no unusual history of breaks. They said my X-rays, MRIs, CT-scans, etc, said differently. I had some healed breaks that I wasn't even aware of, including my lumbar, thoracic and cervical spine. I remember having rib pain a few times from falls in military training, or bike rides, or sports injuries, but didn't realize there were breaks too. I just tended to shrug it off and keep going if I couldn't feel anything obviously broken.

The COVID-19 pandemic motivated me to take the supplements. There have been credible reports connecting vitamin D levels with vulnerability or resistance to the coronavirus.

What piqued me was the report that investigations into COVID-19 in Africa revealed one consistent factor: serum vitamin D level below 25 ng/ml. In Somalia and Sudan, that was mostly women of all ages. Heck, that's my "normal" serum vitamin D. It's been as high as 26 ng/ml once in two years of lab tests a few times a year. Usually it's closer to 20 ng/ml. I didn't realize that was dangerously low.

The theory for low serum vitamin D in such a narrow strata of society? Some Islamic nations require women to be mostly or fully covered any time they leave their homes. Their skin is shielded from sunlight. Unlike their ancestors who got plenty of sun before the demographic shift from indigenous belief systems to Islam.

This coincided (notice I don't say "confirmed") with some theories I read about a year or so ago, published in medical journals but not peer reviewed:

• Avoiding sun may be doing more harm than good. We need sun exposure for our serum vitamin D, and to help the body make nitric oxide on the fly.
• Sunburns may be linked to diet, particularly high consumption of sugar, and too much body fat.
• Sunscreen may not protect us from skin cancer. (This study also warned against specific types of sunscreen.)

That got my attention because I used to sunburn very easily, particularly during a period from age 30-50. That's when I was working full time and more -- either lots of travel, or part time jobs in addition to full time. Like many former athletes I continued eating like I did in my youthful active years. I got double portions of everything at cafeterias for lunch, including two or three desserts. Not surprisingly, my weight ballooned from 150 to 205 lbs.

For years I've either worn long sleeves even in summer, or used the thickest sunscreen I could find. I always wore a hat outdoors. Otherwise 15 minutes in the sun would leave me burned and raw. I never seemed to develop a tan. I'd just burn over and over.

But when I resumed cycling in 2015 I also changed me diet and gradually peeled off weight. I started some diet changes after I was hit by a car in 2001 and discovered I weighed 205 lbs at the time (I never weighed myself and in photos I didn't look that heavy -- my weight was so evenly distributed I didn't have much of a pot belly). But I didn't exercise much -- pain from the neck and back injuries limited me for years. By 2015 I was down to 175 from diet alone. Now I'm down to 150 again.

Last year I experimented with the theory that a keto or near-keto diet and low body fat might be related to resistance to sunburn. Sure enough, at least for me, I tanned but didn't burn. Same this year. I brown quickly but don't get reddish, painful burns. I wouldn't claim it looks good. At age 62, my skin is looking my age. My "tan" is mottled, freckled, with some of those pale reverse freckles from uneven melanin, and a bit thinner -- not quite leathery or papery but it'll get there soon.

Many theories about supplements claim we excrete most of it. That's probably true. But the human body becomes inefficient with age and illness. Maybe we're like a sieve. Perhaps we need a lot of waste to get a little that does some good. Of course we have to keep in mind avoiding toxic overdoses. So I still read the available literature on dosage, etc.

None of this has resulted in any significant improvements in my physical performance. Since 2017 my average speed has improved slightly, less than 1 mph. I'm a bit more consistent, able to maintain a consistent effort. My top speeds are no faster. If anything I struggle more to equal my best times from 2017. But I've had a lot of physical problems since then, so I'm satisfied to be doing as well, if not better.

And as of my most recent bone density tests (January) and lab tests (March, I think), there's still no indication of any improvement. But in March I still wasn't taking my vitamin D and calcium supplements as prescribed. I might take one of each every couple of days, rather than twice a day as recommended. That was partly due to difficulty swallowing for a year after surgery to remove thyroid cancer -- took awhile for my esophagus and trachea to straighten out. Large pills scraped painfully down my throat and sometimes felt stuck, which can induce panic as you can imagine. And I also had to take my thyroid supplement very carefully -- on an empty stomach, with 4 hours between that and any calcium supplement, including an antacid. It seemed like too much trouble so I just skipped the vitamin D and calcium most days.

But I'm taking them as prescribed now -- and more. My usual energy/protein drink every morning and before workouts and bike rides includes lots of vitamins, amino acids, etc.

With the pandemic affecting almost everything, most of my non-urgent care medical appointments have been postponed indefinitely. So it'll probably be next year before I know whether any of this has any measurable effect on my vitamin D level and bone density.

And I'm feeling a bit guilty now about teasing my grandparents back in the early 1970s for all the supplements they took and their preoccupation with health magazines. Now I'm doing exactly the same thing.

Carbonfiberboy 

My last vitamin D test had me at 62 ng/ml, 30-100 being normal. I had a low test a few years ago. My doctor put my on 6000 IU/day of D3 for 3 months, then 2000 IU/day of D3 continuous. So that's what I did and it worked. Gotta be D3.

wphamilton

​​​​​​
You are laboring under a misconception - several. This study does not support your conclusion - the one stated in this title, and the conclusions you posted originally (before your edit). ie, that this indicates that bone density loss is due only to sweating, and that weight bearing exercise has little or nothing to do with it, There is absolutely nothing at all in the study to support it, So please don't ask me to act a fool contacting the author based on your misreading.

Clearly you don't know and you should have just said so instead of all of the "google athletes" and "read the study" nonsense.

Carbonfiberboy 

Are you saying that this peer-reviewed study is simply wrong, i.e. that sweating does not cause a decrease in mineral bone density and that calcium can help prevent same? I would note that I didn't say "only". You inserted that word to create a strawman argument.

My conclusions that weight bearing exercise has little or nothing to do with it is not based on that study, but rather on studies of runners and military personnel, as I've said before. There are also studies to which I have not referred, of caloric intake, suggesting that habitually burning more calories than taken in can lower bone density, and that habitually consuming too little calcium and/or vitamin D can also lower bone density. I suspect that these two effects might be linked, but have not seen a study linking them. There are many studies showing that various hormonal imbalances can lower bone density. I don't know of a study concluding that supplementing endurance exercise with heavy weight lifting maintains or increases bone density. That would be a good one to turn up, but I don't know of one.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6326301/

As above, my post suggests that cyclists could advantage themselves in terms of maintaining bone density, simply following the posted study's protocol and taking 1g calcium, costing about 8 cents, an hour before exercising. The purpose of your posts in this thread seems to be to dissuade anyone from following that protocol, i.e. using argument to prevent other athletes from possibly keeping their bones a little stronger.

bikebikebike

Great thread. Bone and mineral metabolism are exceedingly complex and have lots of moving parts ( variables).
Until the procedure$ of the current blood tests and DEXA $canning were available there were not many ways to get any kind of measure, other than observed fractures. It really remains a more academic than clinical issue.
These tests have a wide variability within the single individual making the end point of avoiding specific fractures difficult to achieve.
Its even harder to get good studies of the specific areas the fractures occur in, making us substitute proxy sites that may differ in correlation.
Bone turns over slowly in most cases and the outcome of any intervention not infrequently takes decades to observe.
So you have a broad range of outcomes that occur over a long period of time. This renders any kind of meaningful assessment exceedingly difficult.
Since the lab tests and scans are real moneymakers that tends to increase the tempo of interventions, and unfortunately that hasn't really produced a substantial changing outcomes.
(Spinal, hip and wrist fractures)
Most of the people for whom this is a concern have many other concomitant problems not in the least related to aging.
That further compound attempts at intervention. (ulcer, menopause, stones, arthritis to name a few)
Still we try.
Doesn't make it any less interesting
Keeps the sabertooth tigers away.
I am currently doing the study on bicycling Norwegian navy women of Somali heritage and comparing them to Norwegian bicyclists in Somalia.