The Science of 80/90 Workouts for Marathoners

In the late 1960's, Dr. Robert Cade, a kidney specialist at the University of Florida Medical School in Gainesville, made one of the great discoveries in the history of sports medicine. Watching the Gator football players wilt in the southern heat and humidity, he wondered if he could help them avoid heat exhaustion and dehydration by replacing their lost sweat. His solution (pun intended) developed into Gatorade, a perfect example of the scientific mind at its inquisitive best. Over the years, Doc Cade’s conclusions have been validated by the countless other experiments that good science requires.

Bart Yasso may not have the credentials of a physician. He has, however, the same gift of empirical observation as Doc Cade, that allows someone to observe a relationship and then wonder if there is some general truth about it. Bart noticed that if he did a speed workout of 10 x 800 meters with a couple minutes rest interval, the average time of the 800’s, in minutes and seconds, seemed to predict his marathon finish time in hours and minutes. He started asking other veteran marathoners about their speed work. Sure enough, checking their logs, they found the same correlation. With that, Yasso 800’s were born and popularized. It’s now time, however, for other scientists to validate Yasso’s conclusion with more controlled experiments.

Tools of the Trade

That

scientific control can come from three sources, one old, one new, and one revised. The "old" source of control is the heart rate monitor, which has been around since the early 80’s. Their effective usage requires each runner to know exactly two very important numbers: actual maximum heart rate (MHR) and resting heart rate (RHR). MHR can be found from either a full treadmill stress test or from field tests during long, hard workouts or races over 5 to 10K in warm conditions. Finding your true maximum heart rate is important because the several age-related formulae for predicting MHR leave 15-20% of the population with actual MHR’s ranging from 12 to 36 bpm’s above or below their predicted number, which can lead to extreme pacing errors. The second critical number, resting heart rate, can be reliably measured by counting it upon awakening for 2-3 days in a row. With these two numbers, athletes can use the Karvonen Formula for determining individualized training HR zones (see box).

The new gizmo for our experiment is a speed & distance monitor. This device tells you with uncanny accuracy how fast you are running and how far you have gone. It’s not a pedometer that just counts your measured steps. The three monitors now on the market (FitSense, Nike and Timex) rely on either global positioning satellite technology or accelerometers in a pod attached to your shoe that sense each stride.

The third handy tool is familiar to both of you who bought my book, The Runner’s Coach. It is a pace chart originally developed by Coach Extraordinaire Jack Daniels, Ph.D. I have used it for over 15 years as the cornerstone of my Effort Based Training philosophy.

The Empirical Test

Being a rather scientific minded coach, I think that I’ve found a way to validate Yasso’s 800 workout. Would you like to be sure that you are training properly to meet your marathon time goal? Would you like to know if your marathon goal is realistic or idealistic? Here’s an invitation to sacrifice your body in the name of science. Seriously, here is the proposal of a low rent scientist looking for subjects with HR monitors to run the following experiment.

My long-time coaching client, Paul Daniele, compiled the chart. Paul is an engineer of the First Order and a frustrated physiologist of High Amateur Rank, who noticed that Yasso’s 800 times fell into the 90% effort column of my original Pace and Effort Chart. It dawned on me that here was the answer to a question that had been nagging me about Yasso’s workout: how hard should the 880’s be? All-out at 100% max effort? A walk-in-the-park 75% effort? We suspect that the answer is found in the 90% columns on the line of your current 10K level of fitness.

To standardize the workout, for recovery intervals I’m recommending a 400 meter jog at a pace easy enough to allow your HR to return to 70%. Now that the distance of the repeats is given, the pace is given, the effort is given, and the interval is given, the only remaining variable is the number of repeats. If you run the workout every week of your marathon training period, start with four and add one each week to reach 10 repeats two weeks before your marathon.

You may have noticed from the chart that we have had to resort to some Coachly Fudging in order to recognize that not all marathoners are built the same. Over a distance this long, runners with lots of slow twitch muscles have an advantage over runners whose higher percent of fast twitch fibers make them better suited to the mile and 5K. As a result, we have distinguished between "realistic" and "ideal" race times and training paces. You pure, experienced marathoners should use the "ideal" columns while you "sprinter" types will find the "realistic" columns more appropriate. When you notice the discrepancies between your actual race paces (the small numbers next to the marathon times) and the Planned Marathon Pace (PMP) runs in the 80% columns, rest assured that there is a good scientific answer involving duration to explain them.

Applied Science

Because of the correlations between fitness, pace and effort, there are several ways to use the chart. For example, if you know that you can run "X" time for 10K, then across the chart from that time, under the 90% column, are the times you should run for your 880 speedwork. The 80% column then offers the pace you should follow on PMP runs that increase in length from five or six to as many as 13 miles over the period of your training plan.

On the other hand, maybe you don’t have any idea what kind of 10K shape you’re in. But if you can run 8-10 x 880 in "Y" time at 90% effort, the average time of those 800’s will tell you what kind of time to expect in the marathon and, incidentally, what kind of shape you must be in for a 10K. One thing should be made perfectly clear: you must use a HR monitor to measure this effort to be sure that you are not under or over-training. Hey, I don’t call it Effort Based Training for nothing.

Something else may have caught your attention. I have deliberately used English measurements by referring to half miles and their equivalents, 880 yards. Years ago, to conform to world standards, we converted all of our 440 yard tracks in the United States to 400 meters by shortening them 7’6"— making each four-lap "mile" 30’ short. Being 30 feet short may not seem like much, but it could result in a sense of pace off enough to keep you from qualifying for Boston. We also run metric distances on the roads but get split times at mile marks. Since that’s the case, why not practice at exactly the same English splits?

Of course, the answer to this specificity challenge is the speed & distance monitor, which can be calibrated to measure your mileage and read out your pace in miles. Another advantage of the speed & distance monitor is that you can run your 80/90 workouts on the roads, trails or anywhere. No more dizzying laps around a track. The freedom of the roads also offers the specificity of hills—found on most race courses. Is this a brave new world or what?