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Run Long, Run Healthy Weekly Roundup — February 17, 2022

Your weekly guided tour of the best new research and articles on running from around the web.

Each week, Boston Marathon winner Amby Burfoot, also the world’s most experienced running editor, curates the latest and most useful content on running and health from around the internet. “I spend hours finding the best new research and articles, so you can review them in minutes.”

THIS WEEK: Training, training, training (Detailed summaries of the large number of important training articles that have appeared recently.) Five reasons you keep getting injured. Stay vigilant against Covid. New results from zero-drop shoes. Complete lifetime running guide. More.

Training, training, training

Three great training stories appeared last week: 1) The debate over “polarized” vs “pyramidal” training; 2) the Norwegian system; and 3) the Olympic gold-medalist speed-skater who trained by running ultramarathons.

Distribution Debate:

Training Intensity Distribution (TID) is one of the biggest and most important issues in all endurance sports. Basically: How often should you train slow, medium, and fast? As long as I’ve been running, most coaches and scientists supported the pyramidal approach: You do a lot of easy running to build your fitness base, and then gradually add more faster running (tempo training), and then quite-fast efforts (intervals) as you get closer to your peak races.

Over the last 20 years, however, some researchers began to support a “polarized” approach. It sounded new and different, so it got a fair amount of coverage. In polarized training, the medium-effort tempo runs are relegated to third place in the training scheme. Some went so far as to call tempo runs a “black hole” for training—a zone of wasted effort.

One way to distinguish systems is to assign a percentage to Zone 1 (slow), Zone 2 (tempo), and Zone 3 (interval) training. A pyramidal system might be 70/20/10. A polarized system might be 70/10/20. Already you can see that the systems are more similar than different.

The journal Medicine & Science in Sports & Exercise recently hosted a “debate” (here and here) on the topic, with a handful of the world’s leading running physiologists including Andy Jones (pro-pyramid) and Steven Seiler (pro-polarized), among others. The Pyramid team claimed victory as the Polarized team mounted a conciliatory defense of their position.

Summary: The Polarized team argued that training more, which requires a lot of slowish training, is more important than training harder. It also argued that the Bill Bowerman hard day/easy day approach “may potentially be as important as TID itself.” It acknowledged that training program success “may depend on the specific event for which the training plan is designed.” That is, 5000-meter runners might need more Zone 3 speedwork than marathon runners. The Polarized team engaged in some hypothetical explanations about “signaling pathways” such as calcium channels and AMPK that they said supported their position.

The Pyramid team argued that there is “limited to no evidence” that polarized training is superior; and that there is some evidence to the contrary. It also noted that a re-analysis of early polarized training papers (based on session “goals”) turned out to be pyramidal training if “time” were substituted for goals. Hence the early papers “were mistakenly identified as polarized.” In addition, many endurance athletes, especially half marathoners and marathoners, regard Zone 2 training as absolutely essential to their programs. These programs are also supported by “exceptionally successful coaches” like Renato Canova and Jack Daniels.

The Pyramid team said they were not pushing the superiority of Zone 2 training but rather appreciating “the strategic value of Zone 2 training in a varied and balanced program.” The Pyramid team proposed that Polarized training might work “in the final taper before competition” in events that last less than 10 minutes. In other words, fast interval training can be good in final peaking for races shorter of 3000 meters or less.

The Pyramid team concluded: “There is presently no evidence that a specific polarized training plan distribution is optimal. Balanced and effective training programs for endurance athletes do and should prioritize Zone 1 and Zone 2 over Zone 3.”

The view from here: I agree that the Pyramid guys won the debate, though the differences between the two systems aren’t great. Two big takeaways: 1) A lot of your training should be slow and comfortable, from 70 to 90 percent of all training; 2) Your tempo/speedwork/peaking should be at paces appropriate to your ultimate racing distance.


A number of Norwegian endurance athletes have been killing it recently in big competitions, including Tokyo Olympic 1500-meter champ Jakob Ingebrigtsen, Tokyo Olympic triathlon champ Kristian Blummenfelt, and the country’s great nordic xc skiers. They seem to use a training method that relies very heavily on moderate training intensities, with a “controlled” amount of faster training (often controlled through lactate testing). They do their tempo runs at the shorter and slower end of the tempo-run range (in my opinion, many runners make the mistake of pushing their tempo runs too fast and too long), and do faster interval-type workouts that don’t attempt to match or exceed race efforts. We used to say “Train, don’t strain,” and that’s still a good maxim.

 The last week or two has seen a number of great articles on the Norwegian system including this one, this one, and this one from Triathlete (with a lot of helpful links).

Speed skating:

I’m guessing that every runner that saw it enjoyed the story of the Swedish speed skater, Nils van der Poel, who trained by running ultra marathons. I don’t think there’s a message here except for maybe “love what you do.” Van der Poel began running ultras because he found them adventurous when compared to the “sucky” monotony of speed skating. He answered some questions from the NY Times. And here’s a deep analysis of his training at Trail Runner.

Five reasons you keep getting injured

When you find yourself in a bad injury tailspin, you need a plan to get healthy and jumpstart your running again. Here’s a great place to start. In recent years, many coaches and physical therapists have invoked point #3 as an important injury-avoidance consideration. Take a look and see if it applies to you. More at Trail Runner.

Covid down, but please stay vigilant

We’re all happy about the drop in recent Covid cases, and hope it will continue. However, there are no guarantees about future variants or other developments, and many reasons to continue protecting yourself and others. A New York Times article says that some long-Covid sufferers have a hard time returning to their exercise programs, and a big study of past Covid-positives published in Nature indicates a substantial increase in heart-related issues 12 months later. This is nothing to mess around with. Some good news: Once again a study has shown that 90-minutes of modest exercise after receiving a Covid vaccination boosts the antibodies produced by the shot. More at Brain, Behavior, and Immunity.

Zero drop shoes … and, yikes, negative drop shoes

Runners have long suffered from knee pains and injuries, and they have also mostly run in shoes with a substantial “heel drop” from a thickly-cushioned heel to the forefoot of the shoes. Are the two related? Could be. A new study of heel-drop in shoes found that “peak patellofemoral joint stress was increased by more than 15% when running in shoes with 15 mm and 10 mm drops compared to running in shoes without a drop.” Researchers made no claims about injuries, and others might surmise that zero drop shoes would increase forces around the ankle and Achilles. More at Gait & Posture. And—zounds!—another recent study claims that negative heel drops (a higher forefoot than heel) could have “better ability to store and return energy.” However, the immediate impact stress of running in these shoes is much greater than in traditional shoes. So, don’t try at home. More at Frontiers in Bioengineering & Biotechnology.

Marc Bloom’s complete lifetime running guide

Marc Bloom is one of our sport’s top writers as well as a serious runner since high school. Here, on the cusp of his 75th birthday, he explains how he has managed to stay strong and fit through the decades. [Personal note: I know Marc well. What’s most interesting to me is that his relative performance has gotten better through the years. In other words, the older he got, the higher he placed among his peers. That’s pure gold.]

I appreciate that Marc generally runs every other day (but does a lot of cross training), challenges himself with tempo runs, has always stayed in touch with speed work on the track, and generally tackles hill repeats of 30, 60 and 120 seconds. Importantly he doesn’t worry about his chronological age, and recites “mantras of gratitude for being able to run at this age and derive so much pleasure from it.” You can’t do better than this for a lifetime-running guide. More at Dyestat.

SHORT STUFF you won’t want to miss

> How exercise preserves cognitive health and protects against Alzheimers

> How potatoes and other “bad foods” are actually good for weight loss

> Coffee or caffeine: Which is better for an endurance boost?


“Go fast enough to get there, but slow enough to see.”—Jimmy Buffett

That’s it for now. Thanks for reading. Stay well, and see you next week.