Bests & Worsts Reviews from Amazon

I have been using the Maffetone 180 rule (180 - Age = target heart rate) for quite some time now. Basically you subtract your age from 180 and that gives you your target training heart rate for which you should never exceed. While I have seen success with this training (I have lost weight, set a new 50k PR, and have remained injury free), I always felt like there was something missing. Even though I saw great results, I always felt like if I did some hard training every now and again, I could become more fit. Maffetone says that the only time you should do anaerobic training is during racing. Well, I run ultra marathons and I rarely (if ever) go anaerobic during my races. So I feel like I have been missing out on that anaerobic training. Fitzgerald's 80/20 principle (or more accurately, the Seiler 80/20 principle) compliments Maffetone's 180 rule quite well. The low intensity guidelines provided by Fitzgerald in Chapter 6, align quite nicely with my target heart rate range under the Maffetone 180 rule. However, the 80/20 principle allows me the opportunity to do some training at moderate and high intensities. Many books and articles vaguely refer to anonymous studies and rarely cite the actual study. The authors use the much to common "some studies say" without telling the reader what the actual study was. This means the reader must take the author at his/her word. Fitzgerald cites almost all of his studies with the name of the study as well as the name of the individual(s) who conducted the studies. This is extremely helpful to a guy like me because I like to find the study and read up on the details. I gave this book a 4/5 because I felt that there were some physiological components of training that were left out. Fitzgerald cites many studies and anecdotal evidence for following the 80/20 rule, but he doesn't go into the physiological adaptations that the body goes through while following the different types of training. For instance, low intensity training causes your heart to be able to pump more blood with every beat by increasing the size of the left ventricle. This type of adaptation does not happen with high intensity training because at high heart rates, there is not enough time for the ventricle to fill with blood, so there is no stimulus telling the heart to increase the size of the left ventricle. This may seem like too much detail, but these are the things I like to read about to know why the 80% helps. Some readers may consider this information superfluous and only want to read about how exactly to train. For those readers, they would probably give this book 5 stars. However, I think Fitzgerald could have included a bit more information on how this training affects the human body. For that reason, I give this book 4 stars. That being said, I enjoyed reading this book and I found it to be very useful. I would (and already have) recommend this book to other runners.