Larger Structures: What We Need To Know

Does the exercise program affect the macro or larger structures within the leg bones? The blog previously considered what happens at the atomic, cellular, micro level, and you may read those posts if interested.

Regards the structure of the bone at larger than the cellular level and how it reacts and builds itself in response to stress and exercise, we'd like to be specific--replace conjecture, superstition, old wives tales and even informed intuition with basic facts to the extent possible in the present state of the science.

The diagram above left illustrates these larger structures of cortical (hard) bone. Note specifically the:

Lamellae
Osteon
Periosteum

Note use of the term "compact" bone as bone is denser on the outside, more porous (spongy) inside.

Recall from the prior posts that the osteoblasts which construct new bone wind up as microscopic osteocytes--the new bone material which is collagen that will thereafter calcify, and that the osteocytes then arrange themselves into the round, tubular osteons. My understanding is that osteons are short instead of long--I've read a distance of a few millimeters to an inch or two. I'm uncertain which. At any rate the tubular osteons seem to end instead of running the length and breadth of the bone.

I'd presume that it is the osteons, their calcification and connection that give the bone its most basic strength. Again, my understanding is that the spaces between the osteons are filled in with calcified material that is weaker but which sort of "sticks" or glues the tubules together.

In the end, I'm thinking, the bones wind up as the equivalent of numerous very thick but short wires. If one wire fractures, the nature of the material makes it less likely that the fracture would extend to the next. This fracture blocking permits swift healing of any single fractured strand.

More, next post.

Training:
Wed. 7/29: The next 3 day cycle starts in terrible ground conditions:
Art: Early in the day Art escapes the farm and spends a few miles pacing after the neighbor's mares. But still has enough left for an energetic 2 miles walk-trot, mostly trot with a few strides of gallop where we can.
Rod: 1.4 miles walk-trot. Getting back into tack work. The knee issue is behind us.

Tues. Misc.

The bone post still needs more work. But, we have been at it at the farm.

Training:
Fri. 7/24: Off

Sat. 7/25: After several riderless days due to weather, we're back with tack work. Will ease back in.
Art 1.2 miles gallop in :20s
Rod: 1.2 miles trot-gallop. then, omg his left knee blows up. Very swollen. rule out knee chip. has to be an insect bite or infection, and sure enough fence scratches in skin above the knee. Hopefully a 24 hour thing.

Sun. 7/26:
Art: 1.6 miles gallop in :18s
Rod: off. knee has gone down considerably but still slightly swollen.

Mon. 7/27:
Art: 5f breeze touching :13s proves a breakthrough from prior work. Nob get's off thinking "racehorse" WU (2f + 1f + 1.5f) + 5f. Through lots of weather we've kept up the every 3 day speed work riderless. It showed in this nice work. Something to build on.
Rod: Still has slight swelling of the knee, but we decide to go. If it's a chip, after all, what difference does it make. 3 miles riderless slow with stops to check the knee. All seems well with the knee!

Tues. 7/27: Both off as it rains again. 4th Tues in July where its rained at least an inch, and this one looks like another three day thing. So much for a dry summer. Rod's knee back to normal.

Friday Training

Blog enthusiasm in this parts has been dampened--pun intended--by continued wet weather here in KC. The ending of the Fairmount Meet 1.5 months early due to that mess in the Illinois legislature hardly helped my mood since Fairmount was a possible destination. Just today as I'm checking trainer violations on the ARCI website I notice that somehow Anthony Downs, Anthony Kansas had a 3 day meet ending July 19. How does Anthony race without a State Racing Commission or State Vet? But, good to see there are still signs of life here in Ks. They also extended by another 60 days before Woodlands would lose their license. I'll be getting to FR shortly!

Training: We're fully into the Preston Burch thing. A speed work every three days is working for us. It is nice that this training method allows 2 days off and you miss nothing--see below. We're at the point were I am very confident in the fitness of my horses and unafraid of big workouts. We should have 3 more speed works in the next 9 days, and then a decision on the race track will be made, weather permitting.
Mon. 7/20: riderless fast work in the mud. Tough workout.
Tues. 7/21: Off, rain.
Wed. 7/22: Off. Still a mess.
Thurs. 7/23: WU + 6f riderless fast as they could go in the mud + 10 min. rest + .8 mile trot under tack for each horse.

More Training:

Tues 7/21: Off
Wed: 7/22 Rollin' Rod get's his lower front teeth rearranged by a kick on the same day vet arrives to do teeth. On very wet ground we take another Preston Burch day off and will do some speed work on Thurs.

Training

Sat. 7/18: both horses trot gallop 2.4 miles, Art 2/3 gallop, Rod 1/2 gallop.
Sun: 7/19: both horses trot gallop 2.4 miles, mostly gallop in :19s or so.
Mon: 7/20: rain again. absolute bs. Breezes changed to riderless speed work on slippery mud. Big workout, but, minus track prep.
Tues: 7/21: off

Training:

The next bone post has been a little slow coming together. Meanwhile, the RR stable has been at it:

Thurs. 7/16: Dry at last and we're able to use the main track first time since Saturday.
Art: Trot-gallop 1.6 miles about 1/2 each.
Rod: Trots 1.6 miles with a few gallop strides.
Fri. 7/17: Off.
Sat. 7/18:
Art: 2.4 miles in 3 heats, 1/2 trot-1/2 gallop for each heat.
Rod: 2.4 miles about 1/3 gallop/2/3 trot.

Larger Structures

A nicely done illustration, above, of cortical(hard) bone construction.

Notice at the bottom an "osteocyte" which is end product of osteoblast construction. Osteocytes then form themselves as a group into Osteon tubules which constitute the basic building blocks of the cortical bone.

Notice further in the illustration the words "compact" and "spongy" bone. The bone is compact on the outside and becomes spongy toward the center. Might we imagine in our conditioned horse there will be less spongy bone and more compact bone around the medullary cavity in the center of the bone?


Notice also in the illustration above the blood vessels and nerve endings. Will the conditioned horse have more blood vessels and nerves per square inch permitting greater materials transport perhaps more nerve stimulation in conditioned animals?

Most important for our race horse are the circular osteons which I'm guessing run along the length of the cortical bone and provide important protection against developing cracks by ending crack propagation, sealing a crack and providing a butress point were recalcifaction of the cracked material can begin.

I am wondering whether in conditioned horses osteons circumference is larger or smaller than in unconditioned horses. If larger, each osteon might have greater strength and force, and, if smaller we'd suppose there would be more osteons in conditioned as opposed to unconditioned bone.

Would our FR program with its result at the micro level also affect the larger structures illustrated above? A brief look at this, next post.

Training: An evaluation of where we are race prep wise was planned for 7/15. And, omg, on 7/16 we have the 5th straight day of rain including two days with significant totals. Our area continues as a center of storm activity even in July. Another full week of race prep thus, down the tubes. Probably never lost anything this week, but zero gain, also. Since May 3 we've lost 4 weeks now due to weather, which means we've had about 6-7 weeks use of our track or 49 days.

And, I'd gage my horses as about 49 day gallopers. They need a little more work. A rush job would require 45 days to a race. But, we're patient. We'll continue to try to turn them into something that will survive after we get there. Next review then on 8/1.


Training:
Mon. 7/13: both horses-- walk-trot 1.5 miles, wet.
Tues. 7/14: To get fast work we decide on riderless in mud. 6 x3f nearly full speed trying to leave a little so we can gallop Wed.

Wed 7/15:
Art: A 2.5 path was cut out of the wet pasture. Art trot-galloped back and forth 4 times or about 2 miles.
Rod: ground conditions dictate more riderless work for the fat one. Horse was galloped riderless off and on 3 miles, planned for slow. But, surprising energy after last nights fast work. Snappy!

Wrapping Up "Frequency"

I was overly ambitious yesterday claiming I was ready to "conclude" regarding frequency. On further consideration, there's more to discuss. It would be pointless to arrive at a final conclusion as to frequency and go away thinking we failed to consider this and that.

Some things coming to mind:

1. Are there any other remodeling processes besides those already considered:
e.g. is "calcification" of the mineral matrix a remodeling process, and, if so, does speed exercise affect the rate, density, depth and strength of the calcified matrix?

2. What about remodeling and the larger structures within the bone tissues. The blog has, thus far, limited the look at remodeling to micro, mollecular, cellular, and atomic. How do the larger structures adopt, and are these affected by the exercise variables, speed, distance and frequency?

3. How does "detraining" of bone tissue fit into the equation? In deciding what speed work comes next, do we also want to know at what point our bone will begin losing strength unless we recommence?

Training:
Sun. 7/12: Off. Rain.
Mon. 7/13: Each horse splashes through 1.5 miles of trot-walk. Tues morn. we wake up to another 1/2 inch.

Race Appropriate Fracture Resistance (FR): Conclusions

I guess I am ready to wrap this up, although there's a bit more thinking to do. Yet to be covered, definitely, the major concern of bone "de-training", whether there are any other remodeling processes besides the one already covered, and, to take an objective look at all the info and see if firm conclusions are really possible.

Recent major injuries cast yet a little more light: Musket Man, Pioneer Of The Nile. I'd viewed a few flaws in the training of Musket Man, although the video showed the trainer to be a young fellow with a head on his shoulders. Baffert I viewed as probably the most technically sound of this year's TC trainers, and he appeared to do a decent (as opposed to "perfect") job with POTN.

If the likes of POTN and Musket Man, who had better trainers than most of the TC horses, go down can we say this is "just racing"?

Readers of the blog know that I think otherwise. Injuries are eminent preventable although great care is required.

So, let's get on with it and finally figure out in the coming posts exactly what we need to do to keep our horse running--

Training

Thurs: 7/10
Rod: Off
Art: Speed work: WU + 5.5f in :13.5s. Strong work.
WU (warm up) was 2.5f + 1f +1.5f with last heat in :14s.

Fri. 7/11:
Art: Off
Rod: Weather related decision to go riderless due to humidity-- large, fat horse: Full speed riderless work: about 6 x 3f with full rests. By the time we started humidity lifted but too late to tack.

Sat. 7/12
Art: 2 miles riderless slow.--we decide to back off a bit as horse has twice in two days escaped the farm and spent 2 hrs. pacing after mares in a neighbor's paddock. Lost a lot of weight.
Rod: Off

Sun. 7/13 Off. Rain

Osteoblast/Clast Remodeling VI: Implications

Can we dare say that most of our good feed throwing trainers are at least remotely aware of the osteoblast process. Probably when Mr./Ms. average trainer think of bone remodeling, osteoblasts are what is referred to. Everyone is (vaguely) aware that exercise stimulates bone remodeling and that this refers to "growth" or "strength". Thus each trainer produces this or that training formula believing it sufficient to do the job of bone growth/remodeling.

Looking at all of this much closer, we take note here that in fact equine bone remodeling is anything but what most people suppose. First, in the horse there is much more to it than mere osteoblast bone building. But, even if remodeling by osteoblasts were the complete process, if you understand that particular process you understand that it is woefully inadequate to the task. Why?

1. Osteoblast remodeling that produces "growth" of the cannon bone or any other bone has short term and long term limits:

a) short term, whatever new bone is produced, it will take two months to maturity, and even at maturity the new bone will be weak compared the old UNLESS the other remodeling processes are appropriately engaged.

b) long term because the cannon bone (and undoubtedly all bones) have growth limits. They only grow thicker to a point. We have seen on the blog that even in an extensively trained horse over many years, the overall cannon bone thickness is hardly greater than horses that have never seen a live race track. We do know the cannon bone also grows inward toward the medullary cavity (bone interior cavity), and that this growth greatly exceeds outward growth. Nevertheless, that growth will maximize and only produce "x" amount of additional strength. If we want more than X, i.e. if we want FR strength, we'll have to do more long term than rely on the osteoblasts.

The conclusion of all this is that with the limited purpose of calculating when our next speed work should occur to maintain FR we consider all the remodeling processes, but understand that the osteoblast process will fail to enter into this equation for two reasons: 1. it is a longer term and continual process instead of something that will be affected by our decision, e.g., to breeze every 3 days instead of every 8 days. 2. Even if we could maximize the osteoblast process the end product will be insufficient to achieve FR. We must engage the other remodeling processes to get FR.

Thus, after the race as I'm there on the back stretch gazing at my radiating cannon bones, and considering--what next-- what part does the osteoblast remodeling process play in my calculations? In the initial stages of training, probably quite a bit. The horse new to training must gain enough thickness at the appropriate places including under the periosteal membrane to withstand initial speed work. How long this takes is another discussion. BUT, after much appropriate training, and our horse being raced, at that point hopefully the increased thickness of bone produced by osteoblasts is mostly in place. Thus, post race, or post breeze, our horse will be unable to get a lot more than it already has from bone growth produced by osteoblasts. Again, the caveat and assumption of this blog--that you have an "appropriately" trained horse with all the connotations.

Training:

Mon. July 6:
Rod: Off
Art: Speed work: WU + 7f (some sub :14) + 2f slow.

Tues. July 7:
Rod: 2.7 miles mostly slow gallop (:21s).
Art: Off

Wed.
Rod: The force is with us (finally) as rain that falls in other parts of KC over last several days misses us. This was to be Rod's first official breezing over our back and forth farm course that has a 2.4 furlong distance were we can go full speed. We normally go back and forth in heats.
As Rod's first work in this pattern we hardly expected things to go smoothly, particularly with this horse. And, we were hardly disappointed. Nothing but trouble initially as the normally totally calm horse for reasons unknown decides to use this night to start spooking at deer. Imaginary, no less, almost losing Nob twice. At that point we abandoned "the course" and decided just to get the speed work in. Galloping in a familiar pattern Rod was all business, and we got in two 1/2 f spurts as warm ups and three 1.5 f spurts in probably :13.5s. Lazy Rod seems to have disappeared for now, as this horse continues to impress, knock on wood.
Art: 2.7 miles gallop in :20s. 2 heats: 1.8 miles + .9 miles. in prep for speed work tomorrow.

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!

Osteoblast/Clast Remodeling IV: Brickwork

Hoping to understand "how often" our race horses "must" engage in speed work to maintain race appropriate fracture resistance (FR), the blog theorized the various bone remodeling "processes" in the race horse. Thus far these include:

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

#4 above is the present subject--osteoblasts and clasts-- with the question: what do they bring to the table in terms of bone remodeling and FR?

Consider again that equine bone might strengthen in several ways:

Circumference and size, inward and outward
Density
Strength and volume of bonding materials
Rearrangement and changes in quality and % of materials

What part do osteoblasts play regards the above? My conclusion (last post on this) had been that osteoblasts affect "bone size" or circumference instead of any of the other factors! If we may compare this process to laying bricks, can we say that regardless of what's under construction, or the form, shape and size the building will take, a brick is still a brick.

That's the theory, anyway. But, this has some logical support. Can we believe the osteoblast/clast bone construction process evolved over the eons, that the process probably is the same or similar in the fish, the dinosaur, modern homo sapiens, and our racing TBs. And, taking this further, the presumption is that the mechanical-chemical signaling/delivery devices that constitute this process are the same for the human couch potato as Usain Bolt setting a 100 meter world record. In the equine, we will fail to affect the process just because we race the horse.

Now, you shrewdly ask, is it conceivable that the continuing stress of athletic training might cause denser new osteoblast bone. We might e.g. due to the stimulus of exercise have more osteoblasts acting in a given area then in the couch potato. This is a legit question but decline going there for the following reason: If you take the trouble to read the exact chemical/physical processes involved in stimulating the osteoblast to act, delivering materials, forming the chemical and atomic bonds--somewhere in combing through such minuta I believe you'll persuade yourself that the material will be constructed in a certain pre-ordained way. Again, in this regard, while we may have more of them, a brick is still a brick.

Thus, for my purposes I will conclude that the osteoblast process will give us new bone material having a certain sameness to it's quality. This has significant implications--next post.

Our training, below.

Mon. Misc.

Training:
Sun. 7/5:
Art: prep for tomorrow's speed work: 2.7 miles 1/3 trot-2/3 gallop very slow.
Rod: Rare night when lazy Rod was hepped up. We decide on riderless speed work full speed 5 x 2f. Horse looked good. The idea was that hopefully the light bulb would come on in terms of speed and the tack work to come.

Mon 7/6:
Rod: Off
Art: Speed work. Last prior speed Nob had reported the horse weakened in the final 2f of the 7f work. Tonight the 7f went in :14s with some sub :14 surging. Nob reports definite wind up there on board. Strong all the way, unlike the last time. 2.2 miles total volume in 3 heats. A final 2f in :13.5 had been planned but was aborted as the 7f went faster then planned and was merely galloped.

June Training Notes

My horses entered July much tougher then going into June. June was punctuated by two weeks of constant rain in the middle, but we never skimped on workouts even when they were riderless fast in the mud. June was a toughening month, even though the raced prep was taken away by the weather.

The last two weeks weeks though have been clear, and we've made nice galloping progress to the fastest workouts to date on 7/3. We're starting to get into dicey territory with our rider weight especially with the smaller horse and because we're pushing due to our early inability to train. The nuances of this as we go.

Plans are to review situation on 7/15 and 7/31. At some point soon we'll head to a race track.


Training:

Sat. 7/4: Off
Fri. 7/3: Speed work for both. Rod was planned and did 2.7 miles intermittent gallop with 2f surges up to :14. Continued to impress with willingness. Art: Planned 2.7 miles aborted after 1.8 miles when heat #2 went faster and stronger than planned. At that point felt uncomfortable proceeding and quit. Close to crossing the line on this one. Better judgment needed. 7f in :15s and some :14s, 160 lbs rider.
Thurs. 7/2: Rod: 2.7 miles mostly slow gallop with short walks.
Art: 2.7 miles, 3 heats, last two snappy, :16s.

Precious Passion

Precious Passions in the United Nations Handicap today had me reconsidering my woman trainer prejudice and checking the PPs. What the heck was that? And, nice camera work. Elvis Trujillo working on a lose rein. Here they are:

6/13 Wins 1 1/8 mile race at Monmouth
5/23 1:02
5/9: 1:03
3/21: 2nd in a 1 1/4 mile race at Gulfstream

I'd give quite a bit to have a conversation with this lady:

x
Slow fractions on the front end. Lol! They must have been checking Ms. Hartmann's vital signs during the race today. Congrats to her! I'd like to know more about the training of Precious Passion!

Thurs. Misc.

Hopefully back to normal blogging tomorrow. Last night's training:

Wed. 7/1/09:
Art: gets 2nd day off.
Rod: 2nd speed work, big improvement. Horse smoother and does it very easily. Nob continues to report how easily big fellow carries weight, and that thus far he's attacking his gallops instead of being lazy as we'd expected. Breathing in the initial stages of every gallop heat continues to be a problem until the horse starts to get his air. Then the breathing becomes normal.
2.7 miles total volume. the aim was to get 3 -4 speed heats of 1.5-2f in there. 3 turned out to be enough as the horse galloped farther and faster then planned. A little :14 stuff here and there.