Update

Blogging

My older son, at age four, readying a new blog post. (Or maybe he is just playing on the computer, an original 128K Mac running OS 1.)

It has been more than two weeks since my last post, and there are a couple of reasons for that:

1. Life continues to be complicated. As I mentioned in my last post, my Dad is doing better at the moment, but my older son continues to struggle with his health. Also, it has been exceedingly cold out, at least by the standard of spoiled Houstonians. All of this I find demotivating.
2. Last week, I planned a really cool post based on a project of my convalescing son that shows off my ride data in fun, new ways. However, my son continues to find ways to make it even cooler, so asked me to delay showing off his creation.

Thus, I decided to use this week to provide some miscellaneous updates.

Riding

My friend "Peter" and I, on a recreational ride back in 1966. The photo was taken by a third friend, "James", who was riding as he took it, which probably contributed to the blurriness of the picture.

Despite distractions leading to motivation problems, I have not given up on a brevet on December 13, but my fitness is not where I had hoped it would be. It has been a while since I posted any MAF test results, so I will make up for lost time. The picture below summarizes my MAF test results from the last 11 months.

I have previously discussed MAF tests ad nauseum, so all I will say here is that I am assuming they are a measure of fitness, that higher is better. At the beginning of 2014, I had gone a long time without riding, so I did several weeks where a daily MAF test was my training ride (MAF Test Only). For the first six weeks or so, I improved dramatically on that regimen, but eventually my results plateaued. In response to that plateau, I significantly increased the intensity of my schedule by replacing two MAF test rides with one long ride and one fast ride each week (Long + Brisk). That had the desired effect of effecting improvement beyond the previous plateau but the undesired effect of being exhausting; I could not maintain that schedule. When I backed off, my performance fell, and before I could experiment with a more moderate schedule, I had to take a break in training to visit my Dad in California (Overtrain, Calif). When I returned, I trained with my wife for the 60 mile Tour de Pink, and as a result , I reached the highest level of fitness of the year, a level of fitness I had only previously seen just before riding a brevet. This was very encouraging! Before I could take advantage of that, however, my son became ill and my Dad started falling, causing me to visit California again, but this time for three weeks and with little time to bicycle. Since my return, I have attempted to regain the fitness I had before I left (Claw Back Fitness) with some success but also some setbacks. I have just over three weeks to get ready if I am to ride a brevet this year, we shall see how that goes.

Exploring

Me during my snarky college years. My friend "ER" and I were out on a ride in 1968 or so and decided to take some posed pictures to prove how clever we were.

A while back, I posted about the growing extension to one of my favorite hike and bike trails, the Braes Bayou Trail. That extension keeps growing to the point where I am beginning to be able to guess where it might be going. The extension actually departs from Braes Bayou, which it could have continued to follow, to branch off and follow Keegan's Bayou instead. Looking at the satellite photos on Google Maps, there are existing dirt paths along parts of Keegan's Bayou, and if I imagined the longest possible extension that could be plausibly built, it is the segment in red on the map below.

For perspective, the part of the Braes Bayou trail I most frequently ride is shown in green. Sometimes I mention I ride this same trail to the east, despite some unfinished, rather dangerous dirt sections (that seem like they would be easy to fix.) That segment is shown in blue. As you can see, as appreciated as every bit of new trail is, this extension is not a game changer by any means. It is not that long, nor does it facilitate the crossing any busy highways or other significant barriers. I suspect its only effect will be to make my standard Braes Bayou ride a couple of miles longer, not a bad thing at that.

Home Again

Continuing construction on the extension of the White Oak Bayou trail connecting it to the MKT trail.

I have been back home in Houston for two weeks, after three weeks in California taking care of Dad. He is doing much better now, so I was able to cancel my return trip to California scheduled for last Saturday. In theory, I could have attempted a 200K brevet on that Saturday, given that I was not out of town after all, but I didn't. The reason I didn't is because I am far from recovered from that trip. Interestingly, I firmly believe that the biggest impact to my form¹ was not the interruption in training (though I was unable to do any cycling at all for the last 12 days of that trip) but from the stress of the trip, stress that has pretty much the same impact on me as overtraining. As regular readers know, I have been trying to do a version of Iron Rider's recovery based training. Unlike Iron Rider, I cannot use my resting heart rate as a guide to my state of recovery, so I have been detecting incomplete recovery by the subjective feeling in my legs, sleep disturbances, grumpiness, and susceptibility to minor illnesses. As always, I watch my MAF test scores as well. For the past two weeks, all of these indicators have been sending me exactly the same message; take it easy. So that is what I have been doing. It is not so much that I have not trained enough for a 200K brevet on Saturday, it is that a 200K brevet would not be taking it easy.

I am developing a long term fascination with the hows and whys of fatigue. When I first returned from California, subjectively, I felt pretty good. The day after my evening arrival, I went for a short, easy ride with my wife. The second day, I rode a MAF test. My score on that test (14.9 mph) was much below what I had been doing before the trip (16 mph) but I felt fine, "in need of speed" if anything. As a result, I rode intervals with my son and daughter-in-law on the third day. I then took a rest day, but after that I felt extremely tired, especially in my legs, a tiredness I have not been able to shake. If my exhaustion is due to my trip to California, why did it take a few days to manifest, at least subjectively? Perhaps relevant, my first MAF test was my worst. Although I continue to feel tired, my MAF test results have improved, almost back to where they were before my trip (15.5 mph). Maybe I was tired from the beginning, but the same stress-response that caused that tiredness was masking the symptoms; as the stress subsided, I both started to recover but also felt the effects. As of yet, I have no answer to these questions, but I am bowing to my feelings and taking things easy. As I have been cycling easily around my usual haunts, I have noticed some changes to the Houston cycling infrastructure, including progress on the extension of the White Oak Bayou trail, shown in the picture at the top of this post.

Rice Track

My daughter-in-law completed her first-ever triathlon while I was in California. Before I left, I rode with her on some of her training rides, including some intervals on the Rice Track. Just before I left, workmen moved the barriers around the track as we were riding, forcing us off the track. When I returned, I noticed the barriers were down. I asked one of the regulars if they knew why, and he told me that the workers had moved us off the track so that they could park equipment there, and when they did, they damaged the track. When I looked, sure enough there was a minor, dinner-plate sized indentation in the track, carefully marked (and obscured) by a traffic cone. The track was shut down as part of a dispute between Rice University and the construction company as to who was going to pay to repair the "damage." It was slightly scary using the track without the safety barriers, occasional Rice commuters would drive across the track on the way to their parking spot, but it was usable. That didn't last for long, however. First, Rice University upped the ante by placing barriers across the track to close it for good:

Then, the construction company repaired the dinner-plate-sized damage by replacing almost a quarter of the track:

However, all is well again, the Rice Track has now been returned to full functionality.

Braes Bayou

While waiting for Rice Track to be repaired, I took to riding Braes Bayou. I was most excited to see that the Do Not Enter sign had been removed from the new trail extension so I rode the extension to see what I could see. Unfortunately, at this point, the extension does not go far. Within 50 yards or so, I ran into a work crew completing the next stretch of trail. I will be curious to see how far this extension goes, once finished. This is what it looks like now:

The workmen are closing a short gap in the trail extension. I wonder what is on the other side?

Even more unfortunate than the short extension, at least for me personally, is that when I stopped to photograph the current status of the trail, I dropped my wallet. When I got home and found I was missing it, I was in total panic! I mentally went through the months required to cancel and replace all my credit cards, replace my drivers license, replace all my medical insurance cards, etc. Worse, at that point, I still thought I was going back to California; how would I board a plane without my drivers license? I rushed back to where I thought I had lost it and ask the work crew, who had not seen it. Fortunately, a wonderful (but anonymous) fellow cyclist found it, read my address off my license, and bicycled out of their way to my home to return it. And people say that the bicycle culture is dead!

In retrospect, I wonder if the trail was actually open for business, or if someone just turned the sign around? Look at these two pictures and decide what you think:

There used to be a sign here saying "SIDEWALK CLOSED". It is now gone.

Or is it gone? This is the same location from the other side. Do you think some enthusiastic user just turned the sign around?

I very much appreciate all the cycling infrastructure development going on in Houston, but I wish I better understood why certain projects are selected, and others ignored. Although I hope that the Buffalo Bayou extension shown above results in significant new riding opportunities, knowing what I do about the local geography, I worry that it won't. Towards the other end of Braes Bayou, there is an opportunity to significantly improve the riding experience, and for many riders, offer a much longer ride, at what I would have thought would be very low cost. (I have noted this opportunity before.) There are two dirt gaps in this trail as it passes by Texas Medical Center and Herman Park. One is a very short and very steep hill that might be difficult to fix economically. The other is longer and, to me, more problematic. This second stretch seems trivial to fix. While the Rice Track was being fixed, I decided to explore it, to monitor its status. When this stretch of trail was first opened, the dirt stretch was quite manageable. However, with use, it has become deeply rutted, make it difficult for me and impossible for my wife to navigate. In my most recent traversal, I noticed that someone had dumped gravel in the ruts, which helped a little. However, as the dirt transitions to a paved stretch, there is a major curb. I was approaching this curb riding into the rising sun, and noticed it only at the last second. Had I not noticed it, I could have had quite a spill. Why not just pave this stretch, I wonder? This is what the curb looks like:

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1) Form results from the opposite effects of fitness (how well trained I am) and fatigue (how tired I am.) Form is defined as my actual ability to ride, all things considered, at that point in time.

The de Anza Reconnect

It was three weeks ago I last posted to this blog. (It seems like forever.) In that post I said:
"[M]y plans for a 200K brevet in November are on hold, perhaps to be abandoned. I will ride as much as I can in California, but between the needs of my father and the absence of my familiar cycling environment, training for a brevet may be more than I can do. But who knows, I will ride as much as I can, substituting intensity for distance, and depending on how quickly my sister and I can get Dad settled, I will see how long it takes me to get back home and what my fitness looks like when do."

Well, getting Dad settled turned out to be much more of an adventure than expected, so much so that I extended my original stay by a week and will be going to California again at the end of next week. Even if I were fit enough for the November brevet, I will miss it anyway as a result of this trip.

But every cloud has a silver lining. Although I did not get much riding in (three rides in three weeks), I did manage to explore some new routes, and to my delight, found that a major gap in the local trail system had been filled! The map below shows large parts of two major trails in the Brentwood/Antioch/Pittsburg region of California: The Marsh Creek Trail (which I have blogged about before) and the de Anza Trail.

Click on map to see a larger version.

Notice the trail labels with a yellow background showing the de Anza, Marsh Creek and Big Bre[ak] trails. From Dad's house, I can catch the Marsh Creek Trail and ride it until it joins the de Anza trail, but where the blue circle is, near the center of the picture, there used to be a gap in the de Anza Trail which prevented me from getting very far. This visit, when I rode that section of trail, I found that the gap had been closed. Here is the new section of trail, going under Highway 4, that has just been completed:

The de Anza trail follows the Contra Costa Canal, so I expected it to be flat. To my delight, this was not the case, as shown by this warning sign:

The climb up to this sign was quite significant for an old man from flat, flat Houston. I always find it difficult to capture hills in my photographs, which is why I included the sign, but I think you can see the trail winding downhill in the picture. But how can this be? The law of gravity would seem to dictate that canals must be close to flat. There are two explanations. The first, which explains the hill shown above, is that the trail briefly departs from the canal and goes over the hill where the canal cuts through it. The other explanation, shown in the next picture, is pumping stations:

Notice how the trail rises to the right of the cement building. On the other side of the building, the canal is significantly higher than it is on the side you can see. (The canal is flowing front to back.) The cement building contains a pumping station that allows the canal to flow upstream, thus providing us cyclists with some modest but nonetheless enjoyable climbing.

I never know how much time I will have to bike when I visit Dad in California. Often, I am going because of some kind of problem that requires my help, and that help may not leave any time for riding. This will be the case when I go back next week. However, if I do have time to ride, there are a lot more trails for me to explore. In terms of brevet riding, the last brevet of the Houston Randonneur's calendar is a 200K on December 12. Will this finally be my 2014 brevet?

Hanging It Up

This picture illustrates a number of points in this post: 1) The hanging bike illustrates the title of this post; once again, the vagaries of life have interrupted my randonneuring plans. 2) My dad's work clothes to the upper right of his walker. We were sad when Dad was driven to use a walker, making the use of his work clothes a thing of the past. Now, we just hope he can return to the walker. 3) The bike itself. My carefully crafted plans to prepare for a 200K brevet in November may be at risk, but even while taking care of Dad, I have a bike to ride.

"Man proposes, God disposes."¹ For my first two brevets, in 2012 and 2013, I used long, rigid training plans to prepare. As regular readers of this blog know, I selected a much more relaxed training plan to prepare for a 200K brevet this November. It is so flexible, it should be resistant to most of life's surprises. Surprise! A few weeks ago I received a text from my sister: "Dad has fallen." A few days after that, "Dad has fallen again, and is in the hospital getting x-rays." I am delighted that the x-rays revealed no broken bones, but what about the next fall? My father-in-law died from such a fall. So, I post this from Dad's home in California where I am staying to both share in Dad's care as well as to help him plot the next stage of his life.

I prepared this post before leaving Houston; Dad's technology resources do not lend themselves to preparing a blog post, nor do I have access to my library of pictures and cycling data here. That being so, this may be the last post for a while, which is its main message. That, and that my plans for a 200K brevet in November are on hold, perhaps to be abandoned. I will ride as much as I can in California, but between the needs of my father and the absence of my familiar cycling environment, training for a brevet may be more than I can do. But who knows, I will ride as much as I can, substituting intensity for distance, and depending on how quickly my sister and I can get Dad settled, I will see how long it takes me to get back home and what my fitness looks like when do. Stay tuned.

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1) A translation from "The Imitation of Christ" by the German-born Thomas à Kempis (c.1380-1471). I claim this proverb is religion neutral. Either take it at face value or use God as a stand-in for fate, luck, nature, the perversity principle or Murphy's Law, as you prefer.

Fitness Smorgasbord

I was the team photographer for the Berkeley Wheelmen while I was in college in the late 60's/early 70's. This is a picture I took of the sprint at the end of a road race. I have included it here to illustrate the concept of training rides ridden at a brisk pace (e.g. intervals.)

Even though I am not an expert on cycling or training, I do value my own experience. That said, there is an extra confidence that comes when I meet a fellow traveler who has come to the same conclusion I have. This happened to me while reading a recent column by Lovely Bicycle. I had been speculating about the efficacy of using brisk training (intervals) to prepare for long rides and she speculates about the same thing. Additionally, Bicycling magazine has weighed in on the topic. As a follower of Bicycling on Google+ (yes, somebody actually uses Google+) I am offered articles on new training plans at least once a week. Examples include "Interval Training for Weight Loss - Burn More Fat", "Ride Faster in Three Days Per Week", and now, in "Quick Cycling Workouts for Power and Endurance." The last article presents a schedule of intervals that Bicycling Magazine claims will improve endurance. Honestly, I cannot tell if they are saying these specific interval schedules are good for endurance or if intervals in general are good for endurance. I hope it is the latter, because the intervals I have been doing don't look anything at all like these.

Another lesson I think I have learned is that it is much better to slightly under-train than to slightly over-train, that when in doubt, I should train less. Recently, Bicycling published an article about Meredith Miller, a professional cyclocross racer, who claims "she doesn't train." An actual reading of the article suggests something closer to what I have been finding; a valuing of resting over training. Once again, it is a comfort when I have made a discovery on my own and I am wondering if it is true or an illusion, to read about someone else making the same discovery.

When I restarted cycling, one of my first influences was Philip Maffetone. He advocates the virtue of training at a low heart rate, roughly Zone 2 on the Zone 1 through Zone 5 system I use. Zone 2 is a relatively easy ride; the test for the proper level of effort is that one should be able to talk in complete sentences while riding in Zone 2, but not sing. Since first encountering Dr. Maffetone's ideas, I have remained both interested and skeptical. Thus, it was of great interest to me when, once again, Bicycling Magazine published an article about the great success Tour de France veteran Fred Rodrriguez had with a training plan consisting entirely of training in Zone 2.

One of the most seductive fallacies in statistics comes from failing to correct for multiple sampling. In a statistical analysis, the result can often be expressed as a P value, corresponding to the chance that the result observed could have occurred by chance. The most common cutoff for statistical significance is P=0.05, meaning that there is only 1 chance in 20 that the result being tested is due to chance. However, if you do 20 different experiments, you are likely to see such a correlation even if all of them are random. Bicycling magazine publishes so many different training plans and articles about training, I have to wonder if I could find one to support almost any training idea I ever had; is this support even meaningful? One the other hand, the article by Lovely Bicycle may well be the only training article she ever published. That one I can take to the bank!

News Flash

On of my most common rides starts at my front door, goes about a mile on city streets to the middle of the Braes Bayou multi-use trail, and then heads west on that trail to its termination at Gessner Road. This is a 17 mile ride, round trip. About four or five months ago, I noticed construction at the end of the trail that promised to lengthen this ride, a welcome change. Unfortunately, after the initial construction, everything seemed to stop. Thus, I was enormously excited today when I got to the end of the trail to see that the previously dirt extensions were now paved:

This trail extension is not yet open, but it seems we are getting closer. I can't wait!

Tour de Pink 2014

Teams are a big part of the Tour de Pink. This is the team my wife and I rode for, the University of Texas Medical School, Houston (UT). From left to right is the zombie himself (team member by marriage), his wife (faculty at UT), our team captain (faculty at UT), and two UT graduate students. Not shown due to late arrival is the sixth member of the team, another faculty member. All teams, including ours, vary in size year to year. This was one of our smaller years. And yet, we were just about in the middle of all the teams in the amount of money raised.

This is the fourth year my wife and I have ridden the Tour de Pink, a ride that, besides being a delight to ride, supports an excellent charity. I have written about the Tour de Pink twice before, in 2012 and 2013, and I won't repeat myself in this post, so refer to those earlier posts if you'd like additional information about this ride. At least over the four years we have been riding, the ride changes very little year to year, the routes for the various distances are exactly the same for example.

My son and daughter in law are visiting us. My son was ill and was unable to join the ride, but my daughter in law grabbed her bike, joined us, and completed the 63 miles with no training. What a champ!

I had been aware of the Tour de Pink for some time because Baylor College of Medicine, where I worked, was a major participant. I could have ridden it as early as 2008, and don't really know why it took me until 2011 to finally do so. For that first year, my wife and I didn't do any special training for the ride. Our weekly long ride was usually in the 35 to 40 mile range, so we figured 47 miles was well within our grasp as it proved to be. In 2012, we set our sights on the next distance up, 63 miles, and were well trained for that distance when life intervened at the last minute, limiting us to a 12 mile ride. In 2013, we were finally able to train for and complete a 63 mile ride. My wife was beat by the end, not due to lack of training, but due to the heat. She resolved that, in future years, she would not try any of the longer routes, but work on riding faster so she could finish earlier in the day, thus beating the heat. That turned out to be a non-issue this year; the weather was delightfully cool, staying between 60 and 70 degrees for most of the ride. Should we have tried for a longer ride? That would require longer training rides, and although we were lucky and had cool weather on ride day, most of our training rides were done under extremely hot and humid conditions, discouraging us from making them too long. Our longest training ride this year was 48 miles, and with that as a base, my wife was able to complete 63 miles at a personal best average speed of 14.5 miles per hour. However, by the end, she was ready to finish; I do not think it would have been wise for us to try for a longer ride this year, even with the perfect weather.

As the sun rises to the right of the next picture, we begin the ride in the same way as the past three years, with the Star Spangled Banner and the riders released longest riders first.

This is the start of the race with the start marked with the same display I have shown in prior years. My wife is Team GPCR (an esoteric scientific reference that delighted her teammates), I am in front and to the right of her, looking to the right, and the woman hidden in shadows with no bike is the "starter" for the 63 mile group.

Last year, I raved about the mini-sausages at Pit Stop #5, but had not gotten a picture of them. This is remedied this year, in the next picture, which also shows some of the other treats.

Whenever a lot of people gather in public places to do something, there is a natural tension between the worthiness of the activity and the enthusiasm of the participants and the tendency for such a large group to be a bit of a disruption. People living near the pit stops are not, in general, delighted to have bicycles dumped on their lawns. This year for the first time the organizers addressed this problem by providing bike racks of a novel design. The bike is supported by hanging either the handlebars or seat over the cross bar. This completely solved the problem, no more loose bikes on neighborhood lawns.

My daughter in law, exasperated at having her picture taken. I actually am including this picture not to exasperate her but to show the bike racks.

The next picture shows me and my wife at the finish. The tents in the background is where lunch was served. You can also see the tables provided for eating lunch.

Every year a goodie bag is provided. Constant each year is a water bottle and a T-shirt, with the rest of the ingredients varying from year to year. In my opinion, the contents this year were the best ever. Among them were not one but two blinkie-lights, shown below. Since everybody was given them, and since assembly began before dawn, the vast array of blinking lights was truly awesome!

Events can be fun because they are completely novel, or because they are friendly and familiar. Tour de Pink definitely falls into the latter category. By and large, the route is great, with wide shoulders, low traffic, and pleasant scenery. By now, I pretty much know where I am at any point along the route, and how far it is to the next pit stop. And best of all, I am starting to know enough of the regulars that I have a set of old friends to greet here and there along the way. Stay tuned for my report on the 2015 edition of Tour de Pink.

Thoughts About Fatigue

The Zombie and one of his fellow Modesto Roadmen in 1965, at the very beginning of their cycling careers, exhausted from an overly-ambitious bike ride.

What is fatigue? On the surface, this seems like a dumb question. Everyone knows what fatigue is. However, as I have been "training" over the past three to five years, as I have thought and read about this question, and as I compared my personal experiences to what I read, I have continued to wonder about the following questions:

1. Is all fatigue the same, or are there different kinds of fatigue?
2. What are the underlying physiological causes of fatigue?
3. What are the best responses to fatigue? Does it differ depending on the kind of fatigue?

In response to question 1, I have tentative concluded that there are different kinds of fatigue. One reason I suspect that is that recovery from fatigue occurs at very different rates, depending on its cause. This makes me suspect that fatigue, like pain, is a symptom that can be a signal for a range of underlying conditions. At one extreme, there is the fatigue and rapid recovery (seconds to minutes) that occurs between intervals of interval training. I believe that this fatigue is fairly well understood. Fast twitch muscle fibers are active during the interval, using either creatine phosphate or carbohydrate as fuel. There is only a few seconds of creatine phosphate available, so it is soon exhausted. When carbohydrate is used as a fuel during intervals, it is metabolized anaerobically, generating lactic acid, which contributes the the sensation of fatigue. During the rest between intervals, aerobic metabolism regenerates the creatine phosphate and metabolizes the lactic acid, which allows me to ride the next interval.

The need to regenerate the fuel for fast twitch muscle fibers is not the only kind of fatigue I experience during interval training. After half an hour or so, I cannot do any more intervals, rest period or no. In fact, it will be two or three days before I can do intervals again. Why is that? The conventional explanation is that muscles are damaged by the intervals, and that days are required to repair the damage. I confess that it doesn't make sense to me that something as natural as exercise should damage muscles, but everyone seems to believe it is so, so I guess I have to accept it as true. However, this raises a further question: does muscle damage result only from the intense effort of interval training, or does it result from easy rides as well? My experience suggests that, if not the same thing, then something similar happens on slow rides, albeit at a slower rate. After I complete a day of intervals, my legs feel tired for the rest of the day; it is difficult for me to walk up stairs, for example. If I do a long ride at slow speed, I have the same sensation. Also similar is that it takes me days to recover from a long ride. If anything, it takes me longer to recover from a long, slow ride than it does from an interval workout. In fact, I have the subjective impression that long rides are the hardest to recover from and are the biggest cause of overtraining. This difference in recovery makes me wonder if fatigue from a long ride is signaling a different underlying cause than fatigue from an interval workout.

Another well known kind of fatigue that has a similar recovery time is bonking. This results from exhaustion of the glycogen reserves in the muscles. I happen to be fairly resistant to bonking, but have bonked once or twice and for me, despite eating extensively, I did not recover until the next day. This seems to be what others experience as well. The oft given advice to eat constantly on a long bike ride is intended, I think, to spare the glycogen reserves rather than to replace them, as the speed of replacement would appear to be too slow to be useful. I think bonking is a bad thing and should be avoided, but I suspect that it does not have a lot of long term consequences, and thus I will not discuss it further.

The kind of fatigue that is the most puzzling to me is that associated with overtraining. For me, this can take weeks to months to recover from. The classic explanation given for overtraining is illustrated in the following two figures (both from the Runner Academy website):

This first figure is the classic description of training; for each time you train, you first lose fitness and then regain even more fitness. If you train again during this period of increased fitness, you will become even more fit the next time. Almost everything about this cycle will vary from person to person, but typically it takes 2 to 3 days after a workout to reach peak fitness, and that you can repeat this cycle about 10 times before your fitness stops increasing and plateaus. The next figure describes what is thought to go wrong when you overtrain:

The classic explanation is that overtraining results when a subsequent workout is attempted too soon, while fitness is still depressed. The notion is that, when you do this, each cycle is worse than the one before, not better. With all due respect to Runner Academy, it is my fervent belief that this explanation must be incorrect, or at the very least oversimplified. Here are the ways my experience differs from the above two graphs:

1. Just prior to experiencing overtraining, my progress looks like the first figure, not the second. Training works fine at first but, without changing the workouts or the time between workouts, my performance declines precipitously, not gradually as shown in the second figure.
2. If one estimates timelines on the second figure, onset of overtraining and recovery take about the same amount of time, about 10 days. For me, I go from performance increasing from workout to workout, as in the first graph, to a precipitous decline in fitness between one week and the next. However, return to baseline fitness takes at least a month.
3. If it were true that overtraining results simply from damaging muscle faster than they can be repaired, then training would simply be about damaging muscle at this fastest rate. This would lead to an optimal level of fitness that could be maintained indefinitely. What virtually every modern training book acknowledges is that this is not the case, all of periodized training is based on this not being the case, and this is very much not my experience. Rather, it is very easy to reach a level of fitness that cannot be sustained. Having reached that level of fitness and won a race or completed a brevet, you must then rest before striving for that level of fitness again.

All of the above implies that there is something other than the maximum rate of muscle repair that becomes limiting when you train for months. One explanation for this commonly given in the exercise community is adrenal fatigue; that the adrenal gland becomes exhausted and is unable to produce adequate levels of hormones. As readers of this blog know, I am a card carrying member of the medical establishment, and the medical establishment firmly rejects this hypothesis. That said, it does have the advantage of better explaining overtraining, and so even if adrenal fatigue is incorrect, then any alternative explanation must involve something similar.

Even though I have no credentials as a coach, I am going to offer a speculative explanation for overtraining. To that end, let me start with a result from animal studies. It is known that you can take half the blood from a rabbit without killing it, it will recover and be perfectly healthy afterwards. In fact, if you take half the rabbit's blood on Monday, you can do the same again on Tuesday. However, if you try it again on Wednesday, the rabbit will die. The reason is that the rabbit has "stem cells" that it can use to regenerate half its blood in a single day. However, once these stem cells are so used, it takes many weeks for them to regenerate. I wonder if, in successive cycles of super-compensation, I am using up muscle stem cells, and that once these stem cells are exhausted, I cannot recover from training until those stem cells have been replaced. As we get older, we lose the ability to replace stem cells, which would explain why training is so much harder for me today than it was 40 years ago. Of course, this is just wild speculation with no experiments whatsoever to back it up, but it is an idea I find intriguing.

Despite being rejected by the medical establishment, the adrenal fatigue hypothesis explains more than my stem cell hypothesis. To explain why, I need to describe one final piece of the puzzle; that things other than cycling affect cycling performance. If I am ill or stressed at work or worried about something, my ability to train is reduced; I overtrain sooner and respond less well to exercise. Thus, there must be some global reservoir of energy in our bodies that is shared by everything we do. We can deploy that energy for training, for work, to deal with problems at home, or to fight off an infection, but energy deployed for one purpose is no longer available for others. As a member of the medical establishment, I do not believe that the reservoir of energy is the adrenal gland, but I do have to say that some such reservoir must exist.

I remain puzzled about the underlying causes of fatigue, especially the long-term fatigue associated with overtraining. Fortunately, I think my ignorance is of little practical consequence. So long as I rest when fatigued, I think I can avoid the consequences of overtraining, even without understanding its cause. Just over a year ago, there was an interesting discussion on this blog about the "Recovery Based Training" approach developed by Iron Rider. Iron Rider has found that he can use changes in his resting heart rate to guide him as to when to train and when to rest. I have not been able to use my resting heart rate for this purpose, it does not change depending on my level of fatigue the way his does. However, I have been using other measures of fatigue; persistent muscle tiredness, being unusually grumpy, and disappointing performances during training; for the same purpose. I have been trying to pay close attention to my level of fatigue and moderate my exercise accordingly. I feel like this has been helpful, but have not been doing it long enough to be sure. I will be reporting on my experiences in future posts, so stay tuned.