Tuesday, December 30, 2008
The basic idea here is that over time the spring holding your foot in gets bent or the body of the pedal gets indented, leaving play in the retention mechanism and letting you out a little too easy.
To fix it, we simply need to retension the spring and everything will work well again. (WARNING: this technique will add about 3g to each pedal. If you care, there's a pair of eggbeaters out there for you somewhere. You may stop reading now.)
Start by cutting a little piece of aluminum sheeting, which can be obtained at a hardware store in a variety of different thicknesses (try .5mm or thereabouts) into a rectangle. Then bend over the end like so:
note that the vertical face in the photo is actually curved a little. This is to keep the metal from buckling as you press it in. If you have a precision pair of pliers that can fold a small ridge on each of the vertical edges in the picture, that helps too.
Next, take your strip and slide it between the body and the spring (you'll see where the spring hits the body - slide it in there) on the side of the pedal that's loose:
Press or tap it in until the end sticks out the other side:
Bend the exposed end over the spring ends that you just squeezed past. This will hold your shim in place. If you want, you can also cut or break off the bent end on the other side, but it does no harm as long as it's below the level of the platform.
If your pedals are still loose after the first shim, simply repeat the steps above with a second one.
Wednesday, December 24, 2008
The ostensible justification for this little indulgence is the demise of my moderately long-lived Cane Creek S-5 headset. It has been feeling awful for a while (I think the compression cap is bent), but now that I can really feel it when I'm riding, it's time for an upgrade. Ostensibly, the S-5 was a 101g headset, and if I was to stick to the rule that upgrades/replacement parts aren't allowed to make the bike heavier unless they add significant new functionality, my choices were limited. Fortunately I have a really big man crush on this German guy named Uli Fahl who came to the rescue with a 79g number named BOBO:
It costs on the order if a CK, but there's roughly 30g less of it, and it doesn't come with the "Look at that guy with the King headset!" stigma. I buy nice stuff because I value high-quality parts, not because I care what other people think of my bike build. A headset cup is a functional component, not a 360 degree billboard, and saving weight by laser etching away all of the anodization with an oversized signature can't be cost-effective--it's certainly not attractive.
I have to admit, however, that I did get the BOBO partially because I have a thing for Tune. There are some aspects of it that would make me fairly uncomfortable if I didn't already trust Uli's Engineering skills. The main two are the aluminum crown race and the plastic compression ring. IMO each of these is under-designed by one material of magnitude (race should be steel and ring should be aluminum), but I'm willing to give the benefit of the doubt for now. Part of the magic of making really light stuff is getting light materials to perform well in situations where you'd never expect them to.
One thing I DO like about this headset is that it comes with a titanium compression bolt instead of the silly aluminum one that one often gets with light headsets and breaks in a week. For those of you crazy enough to ride bikes with composite headtubes, it also comes with a nifty little expansion fitting that replaces annoying starfangled nuts. The impressively thin carbon top cap is elegant as well. Will it last? Dunno. If it can be broken, I'm the guy to break it. Long term testing results to follow... The carnage spreadsheet has been updated as well.
Monday, December 22, 2008
How do you think you got there--not just how you ended up on the floor draped across a few thousand bucks worth of human-powered conveyance and acessories, but how did you became who you are today? What were the nudges? How do we set ourselves up to be nudged in the direction we desire?
Courtesy of a long-awaited monitor upgrade, I was retouching my perennial desktop background this afternoon and realized that not only had I been staring at the same photo since I took it in 2004, but that the camera perspective is remarkably symbolic of how I view my life right now, and I have to wonder which came first, the photo or the perspective it describes so well.
If you care to find out how staring off the peak of Camel's Hump in Vermont will affect your future, click on the photo and take the 1680x1050 desktop for yourself.
More simpletech coming up tomorrow, and in a couple days more detail on something that will be nudging me away from cycling and halfway across the globe for a month or so.
Saturday, December 20, 2008
Just a few weeks ago my father was nearly bedridden after having lost nearly 20 lbs and a horrifying change of meds. His physical therapy is focused on improving his balance and flexibility, and voice lessons are getting him beyond a hoarse whisper. In a sense he is in the base training period, relearning the basics so that he can go on to more exciting journeys. My father and I had this evening discussed the deepest question of all - why is there anything? We have yet to tackle the questions of what is life and what we should do if his heart should cease to beat.
We ask children not what they want to do when they grow up but rather what they want to be. Perhaps we want to be old and happy, with a swarm of grandchildren milling about our feet, or be he who conquers a terrible descent and an epic climb with a grin. There are many things I would rather be doing than grinding through agonizing minutes in the cold cab of my father's truck as he looks for the strength to pull the seat belt across his lap, or overhearing his repeated and exasperated cursing "fucking son of bitch" to his zipper because it won't respond the way it used to. I wish I didn't have to sit with him, he in his wheelchair, and tell him that his clutter and way of life is a burden to everyone around him, that it is unrealistic for him to use a Dremel tool or soldering iron, that what he was is not what he is. Yet, in these moments I detest there is space for peace. These are times to find our compassion for a fellow traveler, to reform ourselves and the boundaries we thought were fixed, and to share in sincerity ourselves. Prior to this visit I was inclined to let be and help only when asked, probably because I myself don't want help unless I absolutley need it. There comes a time though, when even if someone doesn't ask for help you know it is the right thing to do. The cold nights will at times paralyze his walking in violent tremors, and I can now reach out and take him by the arm and give him guidance.
The Zen of these moments is not in stopping the rattling. We control what we can, which in the end may not even be our own hand, but perhaps only our dream of what we want to be.
Between rain and duty, there has not been time to ride.
Friday, December 19, 2008
See, once you're out on your mountain bike in a blizzard and pointed in the direction of the woods, it's perfectly normal to go for a trail ride. You're certainly not going to turn around into traffic on unrideably slick slushiness, and if you stay still you're gonna get cold. The obvious decision is to forge ahead, throwing all caution to the wind, of course.
When I heard severe weather warning for this afternoon my first impulse was actually to try to beat the storm, but one thing led to another until my choices were sit-on-butt or go ride by myself in a blizzard at dusk. The choice was clear. Not long after I had resolved to go kick some snow tooshie, my mom called me to make sure I was inside. (she does this every time there is any sort of bad weather) I told her truthfully that I was, but made the convenient omission of what the future held as I proceeded to "rock" my awesome neoprene booties and winter gloves (Dad, let's keep this on the DL, k?). It was time to go see what all this "severe weather" fuss was about.
To be honest, the most harrowing part of the ride was the road on the way to/from the woods. Fat tires float something wicked in slush, and with no pavement contact the level of grip was akin to riding on warm Crisco (do people even know what that is anymore?). Fortunately for me there was a lot of unplowed snow in the shoulder that was perfectly passable to ride on, and I'm a pretty good snowboarder.
Once in the woods all was good. I managed a whole loop while only tossing myself once, and it was a totally avoidable toss. I did whack my knee pretty hard, but it was walking into my bike, not riding it. Not surprisingly, my Maxxis CrossMarks' performance was beyond awful, as they're practically a hardpack tire, but it's all that will fit in my frame with 29" rims. If the snow isn't too deep tomorrow maybe I'll break out little wheels and the baby killers:
Thursday, December 18, 2008
Rock or rocker, a rattly bike is sure to clatter along out of tune, all around the beat and beg you to put it out of it's misery before too many people get to hear it. For most creaks and rattles a little grease and a wrench will go a long way toward making your rides more pleasant, but every once in a while there's a noise you just can't manage to pin down, and no matter how hard you go at your bike with the wrench it just won't give up. My favorite is the water bottle cage braze-on. Not only does a loose braze-on make the bottle cage rattle omni-directionally through your entire frame, but the rattle also changes rhythm and pitch every time you have a drink, making it as elusive as it is grating. Even if you do manage to realize what's making the racket and take an allen wrench to it, all the tightening in the world can't help you. In every way, the rattly bottle cage is the ultimate zen-killer, and this is Bodhidharma:
Long story short, most bottle cage braze-ons on modern bicycles are not braze-ons at all, but Riv-Nuts, which are a sort of blind faced rivet. In order to tighten the rivet, you have to push on the face while pulling up on the threads at the back without spinning the entire thing in the hole. The gadget above -- made out of a long bottle cage screw, a nut and a washer or two -- is designed to do exactly that.
To use it, thread the nut all the way onto the BC screw, then thread the BC screw as far as you can into the riv-nut. While holding the BC screw in place with an allen wrench, use an open-end wrench to tighten the nut down onto the riv-nut. You want to tighten the nut firmly, but don't wail on it too hard or you will strip it out. IMPORTANT: To remove your tool, hold the allen wrench still and back off the nut until you can turn the BC screw with your fingers. If you try to remove the screw with the nut still tight you might re-loosen the riv-nut.
Ride happy and rattle free.
Wednesday, December 17, 2008
I came back on a one-way ticket, an early return for the holidays prompted by the ill health of my father. About 10 years ago he was diagnosed with Parkinson's disease, a degenerative neural condition primarily affecting the brain's ability to produce dopamine, a regulator of many brain functions including coordination and speech and in the latter stages, memory and cognitive ability. It is interesting that the absence of dopamine gives rise to tremors, often most strongly seen in violent shaking of the hands, which can make eating quite difficult. The brain has a tendency to fall into a steady rhythmic firing of the neurons, which is subdued by the presence of dopamine. Existing treatments often involve the use of L-dopa or dopamine precursors to replace the missing dopamine, however, the long term use of this technique is limited because the brain reduces its dopamine production in the presence of external dopamine.
I'm not sure where things stand at the moment, I'll be visiting my father shortly. He's now in an assisted living center, having recently had a bad spell due to change of medications and general difficulty managing mundane things. It's been hard over the years to watch his degeneration. I want to at times just tell him to stand up straight and do some exercise, to fight the disease. Unfortunately, things are not so simple--in the end we are creatures intimately bound to a body with physical limitations which even the strongest will cannot overcome. The very act of moving can often be difficult or painful, sleeping can be miserable as his body gets stuck in an awkward and twisted position. As if life weren't difficult enough, then one can't even escape in a decent night of sleep.
It hit me hard when I first learned of his current state, it's not easy to see one's parents weaken. It will be good to spend time with him, he's a smart fellow with a proclivity for philosophic discussions, perhaps we can finally tease out the meaning of life, which incidentally, my father claims is not is not 42, at least not exaclty. He claims to have found an asymptotic expansion in the universal quantum bicoherent-information density parameter that when integrated over the two-dimensional entropy partition function of everything/0 and renormalized using the Weinberg formalism comes out at something like 42.011. I'll have to check his math later. Having seen my father go through such troubles (not the mathematical kind), it makes me thankful to have the ability to move freely and gracefully. I think when I do hit the trails again I'll be more aware of the simple grandeur of every pedal stroke and log hopped.
I wish you all high health and happy trails.
First off, the little parallelogram part of the derailleur needs to be kept free of ice/muck/whatever. This can be accomplished with a little rubber bootie:
To make this guy simply cut out a section of MTB tube (This is a 26x1.75-2.1 by the venerable Cheng Shin Tire Co.) just a bit longer than the parallelogram part of your derailleur, then pop the quick-link on your chain and slide it on like so:Once you get it on, you'll have to cut some slots for clearance on the ends so it doesn't bunch up and keep the derailleur from shifting (see first pic). Thinner tubes will be less sensitive to bunching. You can see below how there's a big cutout for the part of the derailleur that attaches to the frame. and a smaller one on the back for the part that goes to the cage.Finally, you want to take a tiny zip tie and poke it through the tube on both sides just in front of the derailleur's cable guide. Use a pin or an awl to make a starter hole. The holes should be as high as you can get them so the zip tie will clear the cable.
Pull the zip tie tight, and everything will stay neatly in place.
Of course the little rubber bootie does nothing for the pulleys, which are particularly prone to freezing in winter. The main reason pulleys seize in winter is ice buildup between the cage and the pulley. If you can spring for a derailluer with a carbon cage, it will be much less susceptible to this problem (because the carbon conducts heat much less well than metal it doesn't freeze water as readily), but if you can't or won't the next best thing is to insulate the cage with a piece of electrical tape. Simply, wrap a piece around each arm of the cage where ice would get stuck between the cage and the moving part of the pulley. Remember to wrap the tape so that the motion of the pulley tightens the tape. The tape solution will likely only work for the bottom pulley, because the pivot of the cage at the top makes it hard to wrap tape all the way around the cage arms. Making your pulleys smooth and slippery also helps to keep the ice from sticking. Coat the faces of your pulleys with a light oil (tri-flow is a good one) before each icy ride, and even if ice does press against them, they'll just slide on by.
Tuesday, December 16, 2008
Both booties are pretty iced up, even before we went and dunked ourselves in a river, but while my bootie provides a nice tight seal all the way around (it has a full rubber sole), Eric's is pretty tattered and loose. When my foot got wet, the water formed an even thicker crust of ice over the bootie, sealing all the seams and preventing any airflow in or out. Eric's, well, didn't so much. My hypothesis is that the sealed bootie became a vapor barrier, locking in moisture and thus saving heat. Eric's booties retained some heat, but were ventilated enough that evaporative cooling could make his foot really cold. The conclusion, maybe vapor barrier liners are a worthwhile investment for cold weather riding. At $8 for socks and $15 for gloves, it's certainly worth a try. I'll order some and let you know.
You should also check out the entire Warmlite catalog (the people who make the vapor barriers). They make great camping stuff and the catalog is delighfully vintage, but OMG SO NOT WORK SAFE.
Sunday, December 14, 2008
If you happen to be fortunate enough to ride in places with fo' real winter, you've probably screamed expletives at insta-freeze first-hand, but with a few gear tweaks and homemade gadgets it doesn't have to be so bad. (For those of you who cheat and live in warm places, much of this also applies to mud and gunk, so read on)
First, let me digress a bit into why insta-freeze happens, because I think it's neat:
In order to turn water into ice, you have to take out energy. When water is sitting in a big pool, it takes a long time for that energy to escape because the surface area is very small compared to the amount of water and transfer of that heat off of the water's surface into the air is very slow, evern when it's very cold. Additionally, when water gets close to the freezing point, it becomes less dense so the colder water will float to the top of a pool, insulating the warmer water below and further slowing the freezing process. In the case of running water, the motion of the water adds enough energy to keep it from freezing. In either case, water can remain unfrozen for a long time after it drops below the freezing point, but it's ALMOST frozen.
That's where you come in.
When you ride through a puddle or stream you splash a thin film of water onto your bike. This thin film has a huge surface area compared to it's volume, so it is much easier for heat to escape. In all liklihood, your bike is also metal, which is an excellent conductor of energy. Since both the air and your bike are below freezing, and the surface area of the water is now very large, it only takes a few seconds for the water to finish it's transition to a frozen state, and in a short time you're riding a giant ice cube.
Since few things short of filling your frame with boiling water (don't try that) are going to keep water from freezing on your bike, the only alternative is to keep the water off.
The most vulnerable component on a bike, IME, is the front derailleur. When riding in ice (or mud), it's always the first to go. There used to be a number of options for "grunge guards" to cover the derailleur armature and keep it clean but they were bulky, heavy and never quite fit right. They're also nearly impossible to find these days. The image above illustrates how to use a soda bottle and a big zip tie to DIY a handy flap that deflects most gunk and keeps everything running smooth.
To make it, cut out a pattern similar to the one pictured at left (you'll have to tweak the flap shape and the cable cutout to work for your frame) from the side of a 2L soda bottle, making sure the curvature of the bottle is going into the drawing. Then attach the flap by wrapping the small upper tab around your seat tube and securing with a zip tie, and you're done. The flap will touch the top of your derailleur (that's what holds it out at an angle), but it won't affect the derailleur's operation.
Here it is in action:
Coming soon, more DIY weatherproofing for chains, rear derailleurs, cables and YOU.
[EDIT: not one, but two people went out of their way to tell me that my filthy bike makes for rotten DIY photos. I really appreciate the comments, though I reserve the right to snarkily call you out for being way too picky when you harsh on the well-used state of my ride . Here's some better pics of the little flap. I didn't really wash the bike, but hey, old habits die hard. Click on the images for higher-res]
Thursday, December 11, 2008
For those of you who are following closely, we didn't actually get to do 50mi in the snow, but that was mainly my fault for having no idea where we were going...
Anyway, on to the porn:
There's a nifty homemade gadget that allows my bike to shift under this mess. I'll show you how to make it soon...
Wednesday, December 10, 2008
1. High blood glucose levels, say following a meal, signal for insulin release. Insulin in turn signals cells to take up glucose, and also serves as a signal to stop using fat as an energy source.
2. For sugars to be utilized by a cell they must first be phosphorylated, which prevents their diffusion back across cellular membranes. The phosphate group comes from the reaction
Sugar + ATP -> Sugar-P + ADP
3. Interestingly, muscle cells do not contain the enzyme glucose-6-phosphatase, which is present only in the liver cells, and is responsible for converting phosphorylated glucose back into glucose so that it can leave the cell membrane. Thus, once glucose is in a muscle cell it is there for good. I think this explains why we get dizzy and lose coordination as exhaustion set in - the brain cells have little glycogen reserves and take most of their glucose directly from the blood. The muscle cells, having no choice but to utilize the glucose that gets to them, are in direct competition with the brain for glucose. The brain's only defense then is to signal to the muscles to stop moving, i.e. the "heavy-legs" feeling. The only way out of this is to provide more glucose to the brain, which means either cutting back on the muscles' usage of glucose, or introducing more glucose to the blood stream.
4. Glucose is stored as long polymers called glycogen, which is a ready-to-use energy storage configuaration. Catabolism of glycogen into glucose is stimualted by epinephrine (addrenaline) and glucagon. Glucagon is released by the pancreas when low blood glucose levels are detected and signals the liver to start releasing glucose from its glycogen stores to feed the muscles and brain. Ephinephrine is regulated by the central nervous system and with norepinephrine (a psychoactive hormone) causes the body the "fight or flight" response.
1. Fructose is not readily absorbed by the small intestine, compared to glucose and sucrose (sucrose=glucose+fructose). However, sucrose can be absorbed fairly quickly in the small intestine, close to the rate of glucose. Also, uptake of fructose, occuring only in the liver cells, is not regulated by insulin.
2. Fructose will readily be converted into glycogen in the liver if liver glycogen stores are low, at rates that exceed that of the glucose to glycogen conversion. However, if liver glycogen stores are normal, then fructose will be converted into lipids (fats).
3. Fruktokinase is the enzyme required for the metabolism of fructose which, interestingly, is only found in liver cells and sperm cells. This makes me think that the fertility of men may somehow be related to the abundance of fructose in the diet. For a gestation period of 9 months, a summer conception really offers about the best chance of survival for a child, being born in the spring and having 9 months under its belt by the time of its first winter.
4. Very small amounts of fructose motivate the activation of glucokinase, which facilitiates the phosphorylation of glucose for production of glycogen. Remember, the fructose is only active in the liver, so fructose is motivating the formation of glycogen in the liver. This means that glucose release to the muscle and brain cells will be impaired by the presence of fructose.
[Wrench edit: See my thoughts about fructose and post-race feeding in the comments section.]
1. Pre-race: According to Keith, at the TransRockies races there was about 2 hours between breakfast and go time. That's a bit short for a heavier breakfast. Probably the best thing here is a good cup of coffee, a solid pile of carbs and some fruit.
2. In-race: We want to be supplying our muscles with a steady source of glucose, but not so much that the insulin causes the fat metabolism to decrease significantly. Ingestion of fructose, causing the liver to retain its glucose as well as being not directly usable by the muscles, makes little sense. Probably the best mixture would be something like 25% glucose, 50% maltodextrin (glucose-glucose dimer), and 25% starch. This combination should ensure that glucose is readily delivered to the muscles (glucose), that the insulin levels are not increased dramatically(maltodextrin), and provides some long-term energy to buffer the drop in blood sugar levels due to the irregularity of eating (starch).
3. Post-race: Immediately following the race we need to replenish our glycogen stores first in the muscle cells, a post race snack high in glucose and absent of fructose is best. Higher levels of insulin, in addition to signaling the uptake of glucose, have the added benefit of stimulating DNA replication, amino acid uptake, potassium uptake, and protein synthesis. Once the muscle cells have a good store of glucose to work with, say after about an hour, we should ingest some fructose in combination with the glucose to motivate the liver to start the storage of glucose in the form of glycogen for tomorrow's race. All of this should be be followed by a well rounded meal and plenty of rest.
Ranking of the available gel products
Lowest Fructose Concentrations:
Luna Moons: brown rice syrup (glucose, maltose, complex carbs), cane juice
Hammer Gel: maltodextrin, fruit juice concentrates
Cliff Shot Gel: brown rice syrup, fruit juice concentrates
Moderate Fructose Concentrations:
GU: maltodextrin, fructose
Carb BOOM: maltodextrin, fructose
Accel Gel: maltodextrin + high fructose corn syrup
Power Gel: maltodextrin + fructose
Highest Fructose Concentrations:
Enervit: Italian company that can't be bothered to supply nutritional information. Their gels contain fish products.
Image credit: www1.br.cc.va.us/biology/lab/chemistry/procedure.htm
Tuesday, December 9, 2008
As with your typical love-musk, the less regularly you've been getting your mack on, the harder it is to resist a good pair of legs. Case in point, we're coming back from a ride out to Bolton or so, cruising down Mass Ave. at a medium pace, and not one, not two but THREE different guys in various states of non-fitness and oddball-dom tried to get me to race them down a busy street at dusk with no lights. Of course, the worse off the guy is athletically, the more aggressive he'll be about taking you down.
The best (worst) of the three was all spandexed out, complete with optional hi-vis reflective construction vest, on what looked like a winter commuter bike (a flat bar, 32c tire sort of deal). I roll by without really paying him any attention and before I know it he's examining my backside at point-blank range. I could tell he was working on wearing me down by the intense expression on his face as he hunched down close to his bars. The hunching must have been squeezing out the last bit of aerodynamic advantage he wasn't getting from riding my 6'4" nearly-180lb ass. After a couple minutes of sitting back there waiting for something to happen, he must have taken my total disinterest in him as a sign of weakness because he blew by me on all three and a half cylinders at a cadence high enough to whip cream (and yes, he had gears). I was all set to watch him blow up in a puff of smoke and cruise by triumphantly when he mistimed a red light, solidifying his place off my back wheel before I had the chance to enjoy the show.
Speaking of guys making trouble on the roadways during training rides, our buddy Seth came out to play with us again on Saturday. He hasn't had time to get out with any frequency of late and has begun self-identifying as fat (see image), which is to be taken with a grain of salt, of course, since we're all cyclists -- a demographic among which eating disorders are more common than software developers at a Star Wars convention. Seth is the best sort of guy to have as a riding buddy because, at least as far as I can tell, he really enjoys kicking the crap out of himself. We'll be riding along 2 by 2, and he'll be up front with you saying how he's about to blow up at the pace you're going, but he'll keep pulling until he's totally shattered and hanging on to your back wheel by a thread, the whole time with this giant grin on his face like he's having the time of his life. You can never count him out either, no matter how bad he's suffering. He'll wait until you're wondering if he's going to need a ride home on your handlebars and the moment you're least expecting it he'll break a sprint up a hill into the wind that's hard enough you need to give it everything you've got to keep him from the pleasure of catching you off guard. He's even sneaky with a camera (not that I'm photogenic when I am paying attention):
This is the Bolton General Store, which totally rocks. The pumpkin spice muffins in the picture are SCRUMPTIOUS -- grilled and covered in butter just the way we like 'em (and the hot chocolate comes with whipped cream on top).
Coming up: Ride Report from our first snow ride and all those tech articles I've been promising.
Monday, December 8, 2008
The loss of coordination was the result of a drop in blood sugar levels. Avoiding this state is especially important for mountain biking, where a small loss of coordination can mean a large increase in frustration, difficulty picking lines and managing obstacles, which in turn causes one to be stopping more frequently and moving into a downward spiral. It's best not to go there.
I wanted to relay some thoughts Keith and I had about on-the-go feeding. The basic problem is this: relying on Power/Cliff bars in the sweltering heat of a summer stage race is a sure way to not eat enough. You have the simple choice between choking to death on a bar as it gets lodged halfway down your parched esophagus, burning 100 calories in a prolonged masticating effort all the while not breathing efficiently, or surviving on a liquid diet. It's one thing to deal with bars on the road, it's altogether another thing to deal with them on the trail where your attention is demanded on a second by second basis. In a stage race like the Breck Epic, one could wait for the aid stations, but overall performance and digestion would be better for a more steady ingestion. The basic task is to replenish, or at least mitigate the loss, of approximately 500 calories per hour on the trails.
As a general strategy, we need to be sure to maintain as best as possible our caloric reserves in the first half of each stage, and that means eating regularly. As the stages can be 6+ hours each, our bodies will be using both fats and carbs in fair proportion. A few basic concepts will guide us through the analysis of the options. Mind you, I'm no expert in this, so please speak up if I am wrong on anything here.
I. Energy Sources - I long ago gave up on Joe Friel and his training cartoons. If you want a plan based on science rather than imagination, try reading something like Tim Noakes' "Lore of Running", it has a great account of physiology of endurance athletes. While the literature suggests that fats can comprise a good portion of the energy supply, about 30% at 50% VO2_max, studies show that the regulator of this process is the muscle glycogen stores. Thus, ingestion of fats immediately prior to or during competition are likely to have little effect, assuming one is not hypoglycemic. The point then is to eat a balanced diet, say something like 40% carbs, 30% fats, 30% protein, and then use carbs during the event to keep up muscle glycogen stores. The question now is what kind of carbs to use?
II. Glycemic index (GI) - a measure of the rate at which a carbohydrate form causes the blood sugar levels to increase. High glycemic index foods quickly enter the blood, low glycemic index foods more slowly. Our guiding principle will be to have an eating/hydration strategy that attempts to keep the blood sugar level as close to optimal and constant as possible. As a rule of thumb it takes about half an hour for a high-glycemic index food to raise your blood glucose level, which again reinforces the idea that we need to eat regularly and often to maintain.
III. Insulin Index - a measure of the rate at which foods (in general, not restricted to carbs) will induce the release of insulin, a hormone which signals cells to take in glucose, depleting the blood of its glucose stores. Foods with a high insulin index are often, though not always, associated with a high glycemic index. High levels of insulin, signaling the muscles to use glucose, can essentially shut down the fat metabolic pathways. Finding a food that keeps a moderate insulin level should allow for a more even utility of fat and carbs.
Fats contain 9 kcal/g, compared to 4 kcal/g for both carbs and protein. Additionally the carbs require 2g of water per g of carb in the metabolic pathway, so in terms of effective energy density per unit mass, fats have about an 8 fold benefit over carbs. This basic fact tells us that when we're operating well below our LT, we should be trying to maximize our utility of fats. Ideally then, we should try to avoid spiking our insulin levels, but keep a steady flow of carbs during exercise.
In summary: we want a food that has a moderate to high glycemic index, moderate insulin index, high calorie/mass ratio, high concentration of carbs perhaps with some fats, and is decently edible. Below are four race-time diet strategies (other than bars) and a brief discussion of each.
Syrup-like sports drink
One could say double or triple the concentration of powdered sports drink like, Accelerade, Gatorade, or whatever. A shockingly dense mixture of sports drink, say 3x, should give a caloric content of 200-300 calories. We plan on carrying only two bottles to minimize weight on the trails. A super concentrated drink requires a chaser of water - a dry, sticky mouth is certainly worse than a plain dry mouth. Two bottles over a space of two hours means that this technique can at most give us about 100-150 calories per hour, seemingly far short of the goal. This suggests the need for a more calorie dense solution.
While certainly refreshing, especially ripe plums and crisp apples, the high fiber content of fruit on long rides can be a downside. Additionally the relatively low calorie/mass content of fruit is a drawback. A few pieces of fruit on a hot day can certainly be a comfort, but it is not a winning strategy. I think we might have progressed a bit in the science of nutrition since the days of the 1960's TdF where fruit and wine were the standards of the day.
In lieu of completely solid food, one might compromise and go for the partially hydrated food source, that mysterious fifth state of matter with fractional phase space dimension, the gel. A single packet of GU contains 100 calories. The gels are essentially all carbs, in the case of GU it is maltodextrin (glucose polymers) which tend to have high GI's around 90-100. The insulin index of these foods can also be high. Benefits: easy to eat, good caloric density. Downsides: expensive per calorie cost, relatively high insulin index. All in all, putting down 2-3 gels between aid stations may be a simple and solid strategy. I am a bit surprised that there is not a gel (that I know of), that contains a more diverse carb distribution, but then again, I am no expert in sports physiology.
---- Edit From The Wrench ----
Adding a couple of things:
There are definitely Gels out there that approach the Insulin Index problem directly. In particular, Honey Stinger is basically pure fructose, which has a low insulin index.
PowerBar claims that the there are separate intestinal uptake pathways for the uptake of fructose and glucose, so that a blend of these two types of simple sugars allows calories to be absorbed faster. Though I am inclined to believe this is true (research supports it), I have to ask the question whether or not sugar uptake is a limiting factor (see next section)? I don't have the answer, but a survey of the different gel products out there suggest that multiple sugars are at least good marketing, as all but Honey Stinger and Hammer Gel seem to use a fructose / maltodextrin mix.
Something else to consider is that the rate at which the stomach contents are released into the intestine (were uptake of the sugar occurs) is slowed by the solute concentration of the mixture. This means complex carbohydrates can be digested at higher energy densities than simple sugars for a given amount of liquid. Furthermore, the concentrations that make the body happy are very low, around 300 mOsm/L, so I would be inclined to believe that this is potentially a limiting factor in the real world where you have limited water and are particularly sensitive to digestive distress. Hammer Nutrition uses this theory as the basis for their gel products, which are based on the complex carbohydrate maltodextrin alone, although the article I linked below concludes that the complex carbohydrate theory is flawed because the receptors that measure the solute concentration reside in the duodenum, where the complex sugars are broken down. Maybe the truth lies somewhere between the two theories? Where's a nutrition scientist when you need one?
Here is a really comprehensive survey of all sorts of things affecting digestion and metabolism of sugars.
Over the next few weeks I'll experiment with home brew medicines for race day feeding. We will attempt to develop a food that combines the desirable traits of being calorie dense, palatable in hot conditions, easily transportable, and containing a somewhat diverse set of carbohydrate sources to keep the insulin spikes down. We might look for a food that combines aspects of the immediate and longer term insulin trigger, something akin to a buffered aspirin.
Thursday, December 4, 2008
Carnage from '08:
- 1 lower derailleur pulley (XTR 970)
- 1 chain (SRAM PC-991)
- 1 cassette (XT 760)
- 1 set of pivot bearings (for Superlight swingarm)
- 1 pair of headset bearings
- 1 set of shift cables
- 2 sets of shift housing
- 1 saddle (WTB Pure V Pro - cover wore a hole)
- 1 pair of pedals (Time ATAC XS carbon)
- 2 sets of brake pads
- NO TIRES!! they're almost dead and relegated to the training wheelset, but still...(Panaracer Fire XCs rule)
- 3 rims (2 Mavic XC717 1 Stan's ZTR Olympic - Taco, dent, broken weld, respectively)
- 2 spokes (Wheelsmith DB15)
- 1 upper derailleur pulley (XTR 970 - cracked in half)
- 1 shock (Progressive 5th Element Air - oil leak)
- 1 fork - 2x (Fox F100x - 1. oil leak and inertial valve fail. 2. bushings wore through enamel on stanchions)
- 1 saddle (WTB Pure V Pro - broken rails)
- 1 rollamajig (Avid - flex joint failed)
- 1 hub bearing (in Tune Kong hub - failed seal on cartridge)
- 1 suspension pivot (SC Superlight - bent)
- 1 chainring bolt (generic - head popped off)
- 1 chain - 2x (SRAM PC-991 - broken links)
- Literally a pile of tubes
The best experience, by far, was with Stan's. After buying a rim and spokes from them and and building it myself, I tacoed it in about three rides. Not only did they replace the rim, pictured below with a broken weld, for free, but they actually rebuilt the wheel for me in the non-standard way I specified (with stainless-steel washers between the nipples and the rim).
On the downside, the new rim didn't look much better than the old one, though they assured me what you see on the right is normal.
WTB was good about replacing this saddle, which I ground through with my leg during the Landmine marathon race.
My favorite interaction, however was with Time,
who replied to the photos above with this message:
Never before have I had a company tell me explicitly not to buy their product. Maybe this is reverse psychology marketing: "Darn it, I CAN use your product whether you like it or NOT! You may think you know what's good for me, but I can do what I want, and I WILL buy your remarkably expensive plastic pedals over and over again, angrily sending their ravaged carcasses back to your US distributor and demanding recourse until the day they fail spectacularly in their weakness, causing me a horrific crash that ends my riding career. [pout]" They sent me free pedals though, so who am I to complain?
Our warranty does not cover wear and tear, and your pedals have been worn past the point of any repair. If you have worn out these pedals to this point in about a years time, then in all honesty, you should consider sticking with our pedals that uses an aluminum body or a different brand of pedals that use a metal body.
If you send us your current address, we will send you a pair of Aliums as a goodwill replacement.
TIME SPORT INTERNATIONAL
info [at] timesportusa [dot] com
877-727-7661 toll-free phone
Anyway, as part of this whole "we're telling you all about our endurance racing experience", we've created a little spreadsheet that will list everything we break or wear out this year and what we replace it with. The running total of how much we spend is up at the top of the sidebar. Click on the number for the spreadsheet.
Image Credit: greasecar.com
Wednesday, December 3, 2008
But seriously, I've been a bit out of it for the last month or so. Just a handful of mtb rides in the last month. Last week Keith and I had our first hill climb session. Today we hit the Fells again. It was rather rough for both of us. Here's a pic of Keith at his high for the morning, really getting this puddle wired, and it only took him three go's. We concluded that our Thanksgiving R&R, which included a lot of sitting on our asses, was a good break for the brain but not the legs. Perhaps most significantly, I noticed my balance and timing were off. Whereas I felt like I was really nailing (=not bailing on) a good portion of the trails even last week, and that was with only regular sessions on the road bike. The point is, riding anything, road or trail, even just a few hours per week goes a long way to keeping up ones basic fitness and muscle memory.
Looking ahead, we're considering shooting for the 50 miler this weekend. Could be snow on the radar for Sunday.... which would make for a good adventure.
It sometimes seems like we'll never get this training program off the ground with so much to do. It's also hard to imagine how the smallest snowball can become a snowman, so here's to perseverance and a good snowfall.