Aerobic Training, Month 2

A bicycle that has nothing to do with today's blog post. This picture was taken in Silicon Valley by my son. I am including it because it is fun, I can't think of a blog post where it would be a better fit, and to liven up this post which is otherwise a bit dry.

Introduction

I have been testing Philip Maffetone's aerobic training regimen ("aerobic training") for two months now, and it seems to be working as advertised, though it is difficult to be certain. It is also unclear that "working as advertised" and "accomplishing what I want to accomplish" are the same thing, though I am hopeful they are. Finally, I have some observations to share that might be of value to anyone beginning heart rate training.

Aerobic Training Results To Date

Since December 3, 2012, I have been sharing my aerobic training results every week at the bottom of each post. Here is the latest:

The jagged blue line connecting the dots reflect the results of MAF (Maximum Aerobic Function) tests, which besides being tests, are training rides; most of my training rides these days are MAF tests. I ride to the Rice Bike Track to warm up, ride around the track for 45 minutes maintaining a heart rate (HR) of 130 to 140 beats per minute (BPM) for 45 minutes, and ride home to cool down. In addition to the MAF test rides, I try to do one longer ride each week. Finally, weekends are reserved for my wife, and she and I do social rides together with no HR monitor. After experimenting, I am trying (but frequently failing) to ride 7 days a week. Of all these rides, only the MAF test rides are shown on the graph above. The grey line is a best fit straight line generated by Microsoft Excel as a measure of how fast my speed is increasing. Excel is claiming that, on average, my speed is increasing by 0.0248 miles per hour each day. That seems like a small number, but if it kept up for a year, I would be riding at 22 mph without exceeding a HR of 140 - Tour de France, here I come! Obviously, it is unreasonable to expect such an increase to be sustained, but it is exciting while it happens.

Given the above graph, why am I not certain that the aerobic training regimen is working as advertised? What Dr. Maffetone promises is that if you regularly exercise at your "maximum aerobic heart rate" (140 BPM for me), your speed will increase, and that is exactly what the graph shows. Or does it? In the first place, notice that the blue line is very jagged - I may or may not be getting faster in the long run, but I am definitely way faster some days than others and very often, I am very slow after having been fast a few days before. Excel also provides a "correlation coefficient" for the grey line. Correlation coefficients range from 0 to 1, where 1 means that the line predicts what is going to happen perfectly and 0 that it doesn't predict what is going to happen at all. In this case, the correlation coefficient is 0.165, a very low value; most of what is going on with the MAF test results represents random day to day changes in speed, very little of it with improvement over time. Thus, the long term increase in speed I am claiming could easily be just due to chance. Second, the weather in Houston has improved over the last 47 days - it has gone from being cold, rainy, and windy to warm, sunny, and calm which, as is explained below, could easily explain any improvement that actually exists.

Why would weather affect the results of my MAF tests? There are three reasons. The first is wind - anyone who as bicycled knows that tailwinds do not balance out headwinds; an "out and back" ride on a windy day is slower than on a calm day. Thus, the wind at the beginning of the training period could have lowered my speed which improved as the wind went away. The second general reason is less obvious, and thus more interesting. There are many things besides exercise that affect heart rate; including any kind of stress. Heat, cold, anger, or fear for example will increase heart rate. When I complete a MAF test on a cold day, the cold itself will increase my heart rate, and thus it takes less exercise to get it up to 140 BPM, again slowing my ride. The third general reason why weather affects my results is rain; it was rainier at the beginning of the 47 days than at the end. I confess, I am a wuss. If it is pouring rain out, I take the day off. It is quite possible (and I firmly believe) that missing days of training has a dramatic and rapid effect on my performance.

Despite all the above, I believe that my performance is improving. In the first place, there were some nice days at the beginning of the 47 day period, and if I look at my performance on nice days with low wind at the beginning and the end of this period, my best performance is a bit faster at the end. In the second place, I can notice a dramatic change in my heart rate during warm up, and even more during cool down. When I began this regimen, it took extreme measures to get my heart rate down near 100 BPM by the end of cool down; a lot of coasting for example. Now, I just ride home, slowly for sure, but without a lot of thought and pedaling all the way. In the third place, when I started, I felt like I was holding myself back on the training rides. I still have to be careful not to let my heart rate go above 140 BPM, but now I have to be almost as careful to keep it from going below 130 BPM and although I don't feel like I am racing around the track, I feel like I need to keep my speed up, so subjectively, maintaining a HR of 140 is getting harder as predicted.

Even if aerobic training is "working as advertised", it is possible that all it does is allow me to ride fast for 45 minutes at a low heart rate when what I want to do is to ride 1200 km from Paris to Brest and  back (or at least 200 km through the Texas countryside) without a thought for my heart rate. I have worried about this, and when I rode 30 miles two weeks ago after having gone a month with no long rides, I found I was very tired and my HR had soared by the end, presumably due to the stress of a longer ride. There were other issues with that ride, but nonetheless I worried. Last week I repeated a 30 mile ride, and it went much better, so I am guardedly optimistic. I am tentatively assuming that this aerobic training regimen by itself will not prepare me for riding a brevet, but that it will prepare me for the training rides that will. What I hope will happen is that, as before, I will have to do increasingly long weekly training rides to get ready for a brevet. However, I am hoping that it will be easier to accomplish these longer rides and overtraining will be less of an issue than it has been in the past. In next week's post, I will describe my plan for getting in shape for a 200K (124 mile) brevet on May 18. I had originally considered trying that with minimal preparation, say one 60 mile training ride a few weeks before the 200K. Based on my current experience, I have rejected that plan and now intend to do the same 10% increases in the length of my weekly long training rides I have done before, starting at 40 miles and increasing to 90 miles. Stay tuned to see if my three months of aerobic training sets me up to complete this series of long rides with greater ease and reliability than what I have been able to do in the past.

Observations on Aerobic Training

In the previous section I tried for a skeptical tone; I think it is important to distinguish between what I believe and what I know. In this section I am going to be more subjective and focus on what I believe.

• Let me start by saying that I really like this aerobic training regimen. I do believe I am becoming more fit as a result but I also believe that it is an extremely gentle regimen. One of the most reliable signs that I am overtraining is a slight ache or tiredness in my legs that persists. Adding a longer training ride the last two weeks has given me just that symptom. What I am doing to treat that tiredness is more aerobic training, and it is working. I feel like MAF test rides are soothing and healing, that rather than making me feel tired, they make me feel energetic. 

• I have developed the feeling that how often I ride has a big effect on my performance; that doing aerobic training every day has much greater benefit than when I skip a day now and then. It is also for these reasons that I have eliminated the rest day from my schedule. When I first started aerobic training, I did what is generally recommended and took one rest day each week. I now feel like a MAF test ride is a better "rest" than taking a day off, so I have eliminated the rest day; when I can, I ride all seven days of the week. I feel so strongly about this, I am seriously considering getting an indoor trainer so that I don't miss my ride on bad weather days.

• I have noticed three major effects of growing old on my ability to cycle. First, it takes me longer to develop fitness. Second, overtraining is a constant risk which means that if I ride more to make up for my difficulty with gaining fitness I am very likely to slip into overtraining. Third, I feel like I loose fitness very quickly, so if I rest to recover from overtraining, I loose what little fitness I had managed to develop. With aerobic training and riding every day, I feel like I never overtrain, I am constantly building fitness, and I never have to take off time that would cause me to loose fitness. Of course, nothing is perfect. For one thing, circling Rice Track 40 times is quite boring. For another, the fitness I develop may be at a lower level than what I could develop if I rode faster and farther as I used to. Nonetheless, I feel like this training regimen is a big improvement overall.

• Something I wish I had been warned about (and thus which I am warning you about) is that at the beginning of the program, following the the training plan as written was basically impossible. In fact, I am still not able to follow the plan exactly though I am getting closer. When I first started, my heart rate would shoot up during warm up and would not come back down during cool down. Even now, my heart rate isn't coming as far down during cool down as it should. Dr. Maffetone says that it should return to 10 to 20 BPM above your resting HR. Since my resting HR is 70 BPM, that means I should get it back down to 80 or 90 BPM which I cannot do, though I am getting closer. My advice to someone starting this kind of aerobic training is to do the best you can when you start out but not worry too much if what you do isn't perfect. Just persist and it will get better.

• Similarly, I find it very difficult to keep my HR within the range of 130 to 140 BPM. Last Saturday was the first day since I started this regimen that I completed an entire 45 minute ride without having either the low HR or high HR alarms go off one or more times during the ride. At the beginning, they would go off on the average once per lap. This feels just like trying to back my car out of my long, narrow driveway:
  
  
  

  

  First I steer the car one way but then as I fear hitting the fence or the house, I overcorrect in the other direction until I am forced to drive back to the garage and start all over from the beginning. The same with HR, it starts to fall, I increase my effort a little too much, and after a cycle or two of that, I have an alarm. This is aggravated by a time delay in the process. I don't know how much of that delay is the time it takes my heart rate to change after a change in effort or how much is that the Garmin has a delay in reporting the heart rate, but the net result is that it is easy to overcorrect when feedback is delayed.
  
  

Conclusions

Dr. Maffetone developed his aerobic training regimen for young racers. However, I believe that it might be even more valuable for us older athletes and those of us not trying to ride fast but to ride long. There are almost certainly too many variables to allow me to ever be objectively certain that this regimen is better than what I had been doing, but I tentatively believe that it is, and if preparation for a 200K brevet in May goes well, I may become a true believer.