Thursday, October 22, 2015

MAF Test Revisited




Probably my most frequent ride is a MAF Test. Designed by Dr. Philip Maffetone as a diagnostic, I have been using my modification of his test not only as a diagnostic, but also as my daily training ride. The way I ride a MAF test is to ride 20 minutes at low speed from my home to the Rice Track to warm up, ride for 45 minutes on the Rice track maintaining my heart rate at just below 140 beats per minute, and then ride the 20 minutes back home to cool off. From a lot of experimentation, I have determined that, for me, on Joe Friel's scale of heart rate zones, 130 to 140 beats per minute is zone 2, the aerobic zone. MAF stands for Maximum Aerobic Fitness, the Test being the average speed I can maintain while staying within zone 2. I have posted on MAF tests on this blog many times before. I began riding MAF tests at the end of 2012 and for the first nine months, I posted an update of my MAF test results at the end of each blog post. Thereafter, I posted periodic updates and analyses of these results. I have recently made some new observations and drawn some new conclusions from my MAF Test rides and the purpose of today's post is to share these with you.

The Graph


The figure at the top of this post is a graph of every MAF test I have ridden, from when I first started riding them at the end of 2012 until a few days ago. I have been riding MAF Tests fairly regularly for going on 3 years now, and when I look at the pattern of MAF Tests scores, I see that the major pattern is that the scores go up and down, corresponding to major events in my life that interfere with my cycling. The lows seem to come every December. In the first place, December weather in Houston is particularly hostile to cycling, and in the second place, chance has decreed that some of the biggest disruptions in my life have occurred during recent Decembers. The main comfort I take from this observation is that when life keeps me from riding for a while, I can quickly regain my lost fitness.

Overlaying the daily, weekly, and monthly ups and downs in my MAF Test scores may be a long term increase in my average score, as indicated by the straight line overlaying the graph, courtesy of Microsoft Excel's best fit function. To be honest, I am far from sure that this long term increase in meaningful, but am open to the possibility that it might be. An alternative explanation is that my life has become more compatible with cycling recently, that I have been riding more regularly for the past few months, and that as a result, my fitness is at a high. Rather than getting progressively better and better, I just happen to be at a peak of fitness right now. There is no way I can think of to distinguish between these two explanations.

What Does a MAF Test Measure?


At a technical level, the answer to this question is obvious and is given above; it measures speed at a constant heart rate. But at a more pragmatic level, that is, what does a MAF test result tell me about my cycling ability, the question is much more difficult. I certainly don't know the answer for sure, but I believe it measures something proportional to how fast I can ride at the end of a "long" ride. (A long ride might be as short as 50 miles or as long as 130 miles, depending on my fitness at the time.) That is, if my MAF Test score is 16 miles per hour, I might be able to ride 14 miles per hour at the end of a 130 mile ride, but if my MAF Test score were 14 miles per hour, my speed at the end of a long ride might be 12 miles per hour.

At the level of physiology, I think it is fairly well established that the MAF Test measures cardiovascular fitness. This consists of two components, the heart, which is used by all exercise, and the blood vessels servicing my cycling muscles, which are mostly specific to cycling. It does not measure the strength of those cycling muscles, and in fact, when I am fit and ride fast MAF Tests, my leg muscles get much more tired and overtraining is much more likely than when I am less fit and ride slow MAF Tests.

Finally, at the level of health, I think my MAF Test score is a measure of that aspect of my cardiovascular fitness that the medical community is so concerned I keep up. Thus, I believe that if my MAF Test score is 16 miles per hour, I am healthier than if it is 14 miles per hour. My reason for saying this is that a MAF Test corresponds exactly to the kind of exercise the medical community recommends for cardiovascular fitness, so if I do as the medical community recommends, and if a score increases as a result (e.g. the MAF Test mph), then I think it is reasonable to suggest that the score is measuring what the medical community cares about.

Is Speed the Only Output of a MAF Test?


According to Philip Maffetone, yes. However, over the years, I have started tracking other outputs that I think give me insight as to my fitness. These are as follows:
  • I use the lap timer on my Garmin cycling computer to measure the MAF Test score both for the whole 45 minutes, but also for the first, second, and final 15 minutes of the ride. On one ride, these speeds may be almost the same. On another, each 15 minute period might be slower than the previous one.
  • I carefully note how I feel. Some of the things I pay attention to is how tired my legs feel, how generally tired I feel after the ride, and, during the ride, if I feel like I want to ride faster and my heart rate is holding me back, or if I am pushing a bit to keep my heart rate up near 140 beats per minute.
  • Although my heart rate during a MAF Test is fixed, there are nonetheless aspects of this heart rate that vary, and which I note. In particular, I note if my heart rate is steady, and thus easy to maintain at the desired rate, or if it is jumping up and down, requiring me to make constant adjustments to keep it in the desired zone. I also note how quickly and how far my heart rate falls during the cool down ride on the way home.

What is the Best Way to Improve my MAF Test Score?


If I have taken a couple of weeks off riding and I ride a MAF Test, my score might be as low as 12 miles per hour. A common strategy I might employ under such circumstances is to ride 6 MAF Tests a week, taking one day a week as a rest day. If I do that, I can eventually get my MAF Test score up to something between 15 and 16 miles per hour, but typically cannot get over 16 miles per hour. This process takes about 6 weeks. If I continue that schedule thereafter, I will maintain that level of fitness, but not improve it.

Once I have reached the steady state described above, I have found two ways of further increasing my MAF Test score; ride intervals1 (riding "fast") and/or ride longer rides2. Both of these raise my overall score, but in different ways. Imagine that after months of riding 6 MAF Tests a week, my average MAF Test score is 15.8 mph. If I look at the 15 minutes splits, I might find that the first 15 minutes I am riding at 16 mph, the second at 15.8 mph, and the third at 15.6 mph, resulting in the observed overall average.

If I replace one of my MAF Test rides each week with an interval ride, I might find that my overall average speed increases to 16 mph. When I look at that result more closely, I will find that my speed for the first 15 minutes of the ride might be 16.2 mph, then 16 mph for the second, and 15.8 mph for the last, for an average of 16 mph.

If I replace one of my MAF Test rides each week with a long ride, my average MAF Test speed might also increase to 16 mph. However, when I look at that result more closely, I find this increase is due more to an increase in endurance than an increase in speed; when I look at the 15 minute splits, the first remains at 16 mph, but rather than falling off, the second and third 15 minutes remain at 16 mph, resulting in an overall increase in the average.

Given the different ways that intervals and long rides increase my MAF Test scores, might I get an even greater increase by adding both to my routine? As described below, I find that I risk exhaustion and overtraining if I do that. There may be training schedules that could overcome this difficulty, and I hope to try just than in the future, but have not done so to date.

Getting Tired


Everything I have read and all of my experience indicates that an optimum training protocol is governed by what I call a "Price Is Right" algorithm; train as hard as possible without going over the limit where exhaustion and overtraining occurs. Regular readers of this blog know that overtraining has been a real problem for me. After searching for an objective measure of overtraining for years, I have given up. What I am doing now is subjectively monitoring how I feel to determine when I am training too hard, and I find that is working pretty well. I find that if I attempt to ride a MAF test 7 days a week, within a couple of weeks, I will experience exhaustion. If I cut this back to 6 days a week, I can continue this schedule indefinitely, and never feel close to exhaustion. If I replace one of those 6 rides with either intervals or a long ride, I can almost maintain a six day a week schedule, but find that I am teetering on the edge of exhaustion and overtraining, and have to take an extra rest day now and then. When I have tried to ride 5 days a week, with 3 of those days being MAF Tests, one a long ride, and one intervals, I was exhausted at the end of two weeks. Could I ride both intervals and a long ride by reducing the number rides per week to 4? How about if I took 1 week out of every 3 as an easy week where I rode only MAF Tests? These are ideas that I have not had the opportunities to test, but would very much like to. Stay tuned!

Loose Ends


Besides monitoring the speed of a MAF Test, I also note my heart rate at the end of cool down, and how steady my heart rate is during the Test. What I have found is that these indicators seem to provide the same information as the MAF Test score; when my MAF Test score is high, I also find it is easier to maintain my heart rate during ride, that it is steady instead of jumping up and down, and that my heart rate falls faster and farther on the cool down ride at the end. That said, these alternative indicators are useful because the MAF Test speed is affected by external factors; it is lower when the temperature is high, when the temperature is low, or when it is windy. If my MAF Test scores are lower than I would expect, and if I am wondering if it is my training plan or the weather, if I see that my heart rate is steady and decreases nicely during cool down, then I am reassured that my training is on track.

Does it make any sense to use a MAF test as a training ride? After all, that was not Philip Maffetone's intent. To answer that question, I would have to know why I am training. One big reason is health, and for that purpose, 4 to 6 MAF test rides a week could not be a better training plan, at least according to the medical establishment. The other is to be ready for more interesting rides as they present themselves. Unfortunately, I do not currently know what interesting rides I am likely to be doing, so to answer that question, I have look backwards. To date, I have successfully completed two brevets3, one in 2012, one in 2013. I had not discovered MAF Tests in 2012 so they were not part of my preparation for that ride. By 2013, MAF Tests were the most frequent ride I did in preparation for my brevet. I was better prepared and turned in a better performance in 2013 than in 2012. Whether that was due to the MAF Tests or due to the greater experience I had acquired is impossible to know, but I do think it suggests that MAF Tests are not harmful as training rides for distance cycling.

Bottom Line


If you have made it this far into the post, you may think me a humorless, unpleasant person, riding around and around the Rice Track, monitoring my heart rate, and ignoring my friends and family. What about fun rides and riding with my wife? Not to worry, I will never pass up a fun ride for a MAF Test, and I ride with my wife whenever and wherever she likes. One of the main reasons I ride so many MAF Tests, and that I ride them on the Rice Track, is because it is on the way to my wife's work. We leave the house together in the morning, she continues on to work, and I turn off to the track to get in my daily workout. When we can manage a fun ride, we do; nothing would please me more than to have my MAF Test rides displaced by beautiful rides through the countryside. While I wait for that to happen, however, my MAF Test rides keep me healthy and fit. See you at the track!



Footnotes


1) Examples of intervals are as follows:
  • Ride from home to the Rice Track as for a MAF test. Ride 15 minutes at MAF Test speed. Then ride 6 laps as fast as I can, ride at MAF Test speed for two laps, and repeat for a total of three times. Ride, maintaining a MAF Test heart rate, to complete a total of 45 minutes on the track; typically 5 to 10 minutes. Ride home from the Rice Track as for a MAF test. 
  • Ride from home to the Rice Track as for a MAF test. Ride 15 minutes at MAF Test speed. Then ride 1 lap as fast as possible, 2 laps slowly, 2 laps as fast as possible, 3 laps slowly, 3 laps as fast as possible, 3 laps slowly, 2 laps as fast as possible, 2 laps slowly, and 1 lap as fast as possible. Ride, maintaining a MAF Test heart rate, to complete a total of 45 minutes on the track; typically 5 to 10 minutes. Ride home from the Rice Track as for a MAF test. 
2) Long rides are 30 miles long or longer. I selected this number from experience, this is the minimum length of ride I have found that will increase my MAF test scores.

3) A brevet is a challenge ride where the challenge is to complete a relatively long distance in a generous but fixed amount of time. A more detailed description can be found on the United States Randonneuring website. The brevets I completed were each 200 kilometers (124 miles) long and had to be completed in 13½ hours.



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