Bicyclists - Thinner Bones?


(Janelle) #1

I can’t call myself a cyclist any more but I was at one time. I’m big boned but if I had a slight frame, I’d add in some different training maybe?


(Alex ) #2

too little pressure?!!? Surely that’s preferable to the joint abuse that a life time of running might cause?


(Central Florida Bob ) #3

This is one of those stories that comes up (dare I say it?) cyclically. Every now and then. I recall reading it in the mid-90s.

It seems to be a real effect, but notice they measured it in “elite class” athletes? “They wound up recruiting 21 high-level runners and 19 road cyclists, men and women, most of them in their 20s and all of them lean, fit and with several years of intense competition behind them.” (I added the bold) The first study I saw was in Tour de France riders back when Lance Armstrong was bringing the Tour to America’s attention for the first time in years.

So does it matter to a non-elite cyclist? For convenience I’ll define elite as “someone is willing to pay you to ride for them”, not just the few top contenders for a world-class tour. I don’t think anyone can honestly answer that even 20 or more years since they first noted it.

And I don’t think any doctor would ever tell you it’s better to be sedentary than to ride a bike. If you like running better, run. If you like cycling better, cycle. If you like gymnastics better, do whatever that verb would be.

AFAICT.


(Allan Misner) #4

I think the point is that some resistance exercise is needed to prevent osteopenia.


(Central Florida Bob ) #5

I don’t think it’s fair to say that based on what’s published. Toward the top it says:

The cyclists also did more weight training, with most of them heading to the gym during their off-season for intense lifting. None of the runners did that.

That implies that resistance isn’t the key, but that the impact from running might be.

This part is five paragraphs up from the bottom:

This study cannot tell us, though, why cyclists’ bones might be thin, he adds. They could have been eating too little or sweating too much for ideal bone health. Both low calorie intake and high rates of calcium loss through sweating have been tied to bone loss in other studies.

More surprising, the cyclists’ heavy weight training seems not to have built much bone.

So twice they say weight training doesn’t seem to be protective.

This is an association study, like virtually all the dietary studies that have caused so much trouble. All it can tell you is that in these two groups, cycling was associated with lower bone density. In particular, it can’t say anything about causation.

A problem with all these studies is no randomization. Two self-selected populations are looked at and we find one is different from the other. There can still be selection bias here. What if there’s something about the genetics of people who choose to run vs people who choose to ride? Or cyclists inhale more pollution than runners, by virtue of being outside longer? Or cyclists eat more carb loaded crap than runners because they’re engaged in their training longer? The association study can tell us nothing about this because it doesn’t control these things.

In a Randomized Controlled Trial, if you can’t randomize the groups you can cross them over: make all the runners cyclists and all the cyclists runners for a few years and compare them again, but they’re not a controlled trial and can’t do that.

Back in the 70s, they said running a marathon made someone immune to heart attacks because no marathon runner had ever suffered one. It was pure self-selection bias. People running in the early 70s were a small, self-selected group doing a marginal activity. Once the running craze started in the mid-70s, people from all imaginable backgrounds started running marathons and marathon runners started being reported having heart attacks.

Looking at how long this turned out (I swear it just started as one or two thoughts!), this looks like I’m jumping on you. I swear that isn’t why I wrote this. Nor do I think you were attacking me. I do have a free-floating disgust with so-called “science” and the way things like this study are done. I think this is just another overblown study presented simply to generate clicks for the paper.

I leave this in hope it’s useful to someone.


(Bunny) #6

Vitamin D & K intake is adequate and less sugar (…and less heavily processed carbohydrates) in the diet; you will have thicker bones.

Phosphorus always opposes calcium in the presence of high glucose…

Footnotes:

[1] Is Trisodium Phosphate in Food Bad for You? Facts vs Myths: “…Organic phosphorus is much less absorbable than inorganic phosphorus. The digestive system only absorbs around 40–60% of organic phosphorus, while it absorbs up to 100% of the inorganic phosphorus found in foods like cereals, cakes, soda and deli meat (6). …” “…Since inorganic phosphorus is more effectively absorbed by the digestive tract, it affects the body differently than organic phosphorus…” “…Organic phosphorus, which is found naturally in foods like dairy products and meats, has a much lower and slower absorption rate than the inorganic type of phosphorus (sodium phosphate) added to processed foods. …”…More Note: What your bones and teeth actually are (Trisodium Phosphate) on the periodic table of elements…

[2] Food grade in-organic Trisodium Phosphate can also REGENERATE tooth enamel …More

[3] Disorders Involving Calcium, Phosphorus, and Magnesium: “…In bone, parathyroid hormone increases bone turnover, resulting in a release of calcium and phosphorus from bone. Lastly, PTH works directly on the kidney to increase renal calcium reabsorption and decrease renal phosphorus reabsorption. The net effect is a rise in serum calcium but no net change in serum phosphorus. …More

[4] Effect of glycemic control on calcium and phosphorus handling and parathyroid hormone level in patients with non-insulin-dependent diabetes mellitus: “…The present study was undertaken to determine whether improvement of hyperglycemia alters calcium and phosphorus handling, parathyroid…” …More

[5] ”…Vitamin K is found in high concentrations in the salivary gland where it breaks up dental plaque. …” ”…Activator X (Vitamin K) also influences the composition of saliva. Price found that if he collected the saliva of individuals immune to dental caries and shook it with powdered bone or tooth meal, phosphorus would move from the saliva to the powder; by contrast, if he conducted the same procedure with the saliva of individuals susceptible to dental caries, the phosphorus would move in the opposite direction from the powder to the saliva. Administration of the Activator X concentrate to his patients consistently changed the chemical behavior of their saliva from phosphorus-accepting to phosphorus-donating…” …More

[6] 9 Chia Seeds Benefits + Side Effects: ”…Chia also contains boron, which is another essential nutrient for bone health. Boron helps metabolize calcium, magnesium, manganese and phosphorus for healthy growth of bones…” …More Note: Boron makes bones super strong with more elasticity!

[7] 3 Major Benefits of Vitamin K2

Note: K-2 is the fat soluble form of K also found in Nattokinase

[8] Proper Calcium Use: Vitamin K2 as a Promoter of Bone and Cardiovascular Health: “…However, vitamin K deficiency results in inadequate activation of MGP, which greatly impairs the process of calcium removal and increases the risk of calcification of the blood vessels.48–52 Because that calcification occurs in the vessel walls, it leads to thickening of the wall via calcified plaques…” …More

[9] Additional factors affecting serum calcium levels: “…As you can see from the above discussion, calcium and phosphorus have an inverse relationship: when calcium levels increase, phosphorus levels decrease, and vice versa. pH also affects the level of ionized calcium. As pH rises and blood becomes more alkalotic, calcium binds more easily with protein, causing the level of ionized calcium to drop. Conversely, when pH falls, causing acidosis, less calcium binds with protein, which raises the ionized calcium level…” …More


(Bacon is a many-splendoured thing) #7

What kind of food are these cyclists eating? I’d be willing to guess it’s the SAD, amiright?

So keto is known to put on lean tissue and increase bone density in people. I tend to think this may be a problem for sugar-burners, but not for fat-burners.