Osteoblast/Clast Remodeling V: What Stimulates The Process?

While on the subject of bricks I came across this. A mansion from Mission Hills , KC? No. It's Mary Arden's family home. Yes, that Mary Arden, the mother of William Shakespeare. Reminds of our present gaudy faux mansions of our good upper middle class. We've progressed less in 500 years perhaps than I'd supposed.

But, on to the business at hand. What to make of new bone produced by the osteoblasts that--according to this blog--has the same constituent nature regardless of the exercise load of its host.

Before getting to the implications of this, this post will cover some additional things we should understand about the process.

Four remodeling processes were described last post:

1. Bone glue changes.
2. Compactive changes in the mineral lattice.
3. Rearrangement of material.
4. Osteoblast/clast remodeling

Of these only osteoblast remodeling provides permanent changes as the other three processes are analyzed as temporary, in that unless reinforced by appropriate exercise their effects will disappear. And, as noted over several April posts, the above described temporary processes are stimulated only by appropriate speed work. Slow galloping e.g. will have zero effect on compacting the mineral lattice, etc.!

BUT, in all likelihood, osteoblast remodeling will be stimulated as much by the total volume of exercise, including the slow work, as by the speed of a race. Why is this so? The answer seems to be that the chemical--mechanical signaling which stimulates osteoblasts begins with any sort of exercise at all. Consider again the calf cannon photos:



The exercised calves were merely trotted a few minutes a day for (as I recall) 4 months.

Concluding then what we need to understand about osteoblast remodeling:

1. It occurs in response to any exercise including slow galloping.
2. The bone material produced as a result will take about 2 months to reach maturity.
3. Qualities of newly formed bone will be the same regardless of the intensity of exercise. New bone is of the same strength and molecular make up for our potato chip aficionado and our conditioned athlete.
4. While over the long haul adding new and additional bone to the cannon bone will geometrically strengthen that bone, over the short run the new bone will be weaker in the appropriately trained horse than the more mature bone tissue. By long haul I refer to 6 months to 2 years. The short run would mean from now till probably 4-6 months from now. Thus for the first 6 month of its existence, our new bone--unless acted on by the other remodeling processes, will be relatively weak!

Implications next post.

Training:
Mon. 7/6
Rod: Off
Art: Speed work. 2.2 miles total. .9 mile WU + 7f in :14s with sub :14 surges + 2f slow gallop.

Tues. 7/7:
Rod: 2.7 miles slow gallop--planned a nice smooth continuous and best gallop to date event. Result: the horse absolutely refuses to change any lead and has to be repeatedly brought to a trot to lead change, and then frequently refuses to get on the necessary diagonal. And, all this is complicated because the horse keeps stopping up on his breath starting up the next gallop. This one turned into a worst gallop to date fiasco. But felt a little better later when I remembered we'd simply never slow galloped this horse. Today was his first effort, and, responded as you might expect. First serious breezing on Wed.
Art: Off.

Wed: 7/8 Rod--we've planned 3 x 2f breeze work. Will be interesting how this first one turns out!