IMHO, this is THE book you need if you want to make huge jumps in your running performance.

A little background: I just started running three years ago, at age 50. Until I got this book about six months ago, I just went out and ran with no plan. My runs were pretty much the same effort (heart rate zone), equating to what most folks would call tempo runs or a little bit faster. I did vary the mileage quite a bit, however. And sure, that method gradually got me a little faster over the years (more so at first) sometimes cutting off a few seconds from one 5K race to the next, though not always. I was kind of plateaued.

I decided in May (2015) that I needed a REAL plan to prepare for my first marathon, later in the year (October). So, I started following the Marathon Level 1 plan in this book. Really, my goal for the training was to merely finish the marathon, with little expectation that it would allow me to perform better at an upcoming 5K (August) and a half marathon (Oct 10th). But, during the training I noticed I was running faster and faster at the same heart rate.

So let's cut to the chase: following this marathon raining plan, I PR'd in the August 5K race by 35 seconds, finishing in 22:21. Then, two months later I shaved 10 MINUTES off the half marathon, finishing an extremely hilly course (Freedom's Run in the rolling hills of West Virginia) in 1:46:56 (compared to same race in 2014). There is NO WAY I could have run an 8:09 pace for the half - for almost two straight hours of running - without the unbelievable aerobic improvements this book has allowed me to attain. Further proof: my Strava suffer score for the 2014 Half was 333 ("epic suffer" rating) compared to a 243 for the same Half this past weekend. I ran about 50 seconds PER MILE faster BUT at a LOWER heart rate! That, to me, is unbelievable.

So yeah, buy this book. It's concise, packed with scientific proof, and has training plans for 5K, 10K, Half's, and full Marathons. Even if you don't race, following his 80/20 rule will make your runs MUCH more enjoyable and productive, insofar as improving your aerobic fitness level.

One more note: while I usually buy Kindle versions of books, I bought the paperback edition and was glad I did. I wound up going back and forth repeatedly between sections, particularly the tables with the myriad different runs (long, tempo, intervals, fast finish, etc.) and the tables with the prescribed runs for a particular training day. I even affixed colored tabs to make it easier.

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.

I am an avid runner, and compete regularly. The name of this book really caught my eye, and I was intrigued just by the title. After reading the book, everything he was saying made sense to me. So I decided to give it a shot for myself, although I was running easier I did notice my times getting faster. The only thing I didn’t like was the satisfaction after every run of running hard, and having a truly hard work out. It was the hardest adjustment for me, but I continue to use this method now, and have continued to see my times fall!