September 1, 2022

THIS WEEK: Air Force believes stride changes a good idea. How long should your long run be? Strength training improves running economy. Can running shoes prevent injuries? Get maximum mileage from your (expensive) shoes. Grass no softer than cement. Get hip about knee pain. The latest nutrition scheme--drips. And much more

Big Air Force study supports stride changes

Those who believe you can change your running stride to decrease injuries

have often faced disappointing results in studies, to which they have responded: “Give it time, give it more time.” A new Air Force paper suggests they might be right.

The Air Force cares about running injuries, because every drop-out from basic training costs the USAF $55,000 in wasted resources.To see if this figure could be reduced, the Air Force recently assigned more than 2000 basic-training recruits to “large group, motor learning-based running gait training.” The training focused primarily on three things: 1--moving initial ground contact under the center of mass; 2--higher stride rate; and 3--increased hip extension through the drive phase.

Recruits in the gait-training group experienced modest but important changes vs the non-trained group. At first, however, they did report more soreness and muscle pain, as has so often been noted among those attempting stride changes. But these complaints did not develop into “significant or debilitating injuries” because recruits were “given the time and opportunity to adapt to new run patterns.” (The training lasted 8 weeks.) Conclusion: “Large-group, running gait training was associated with a significant reduction in injury severity.”

The study is by far the largest of its kind. The research group believes the stride training reduced Air Force costs by $2.3 million dollars that could stretch to $5.2 million if extended to more recruits. Also, they propose that injury-reduction could be even greater with a core-training curriculum that was not included in the study. More, including free, full text, at Military Medicine.

How long should your long run be?

The weekly “long run” is part of all serious training programs, and coaches often advise that it should constitute 20% to 30% of your total mileage for the week. But is that what top runners actually do? We don’t often see data on large groups of elite performers, so this week I took another look at the recent paper on 146 women who raced in the 2020 U.S. Olympic Marathon Trials. 

This time I focused only on their average weekly training mileage (78 to 84 miles), and their average longest runs (21.5 miles) while preparing for the Trials. That works out to roughly 25 percent of total mileage, so it seems these women followed the basic rule. Or maybe the rule followed them, because that’s the way these things often work. It also reflects what Jason Karp found in his paper on the 2004 Marathon Trials runners. 

It’s likely that many marathon runners who cover far fewer miles per week would actually run a higher percent of total mileage in their long runs … because you gotta do what you gotta do. More at Int J of Exercise Science.

Strength training of any kind improves your running economy

Thinking about adding some strength work to your running miles?  Don’t sweat the details. Just do it. A recent study looked at 26 middle-aged distance runners (av age 51) who added heavy resistance training, heavy resistance with plyometrics, or light, endurance-like resistance with plyos. After 10 weeks, all three groups improved their vo2 max and running economy by the same amount. Conclusion: “These findings suggest that any type of resistance training may be beneficial to improve economy in middle-aged runners.” More from abstract at Amer Coll of Sports Med annual meeting.

Can running shoes prevent leg injuries?

Cochrane Reviews are highly regarded, independent reviews of key areas of health and medicine. So it was exciting to see Cochrane tackle the question: Can running shoes prevent leg injuries?

The answer is … well, there isn’t an answer. Not when the conclusions, based on the best available research, are primarily “uncertain” or “little or no difference” or “no evidence.” This refers to analysis of minimalist shoes, neutral shoes, cushioned shoes, motion-control shoes, shoes with soft and hard midsoles, and shoes prescribed according to your “foot posture,” ie, high or low arches. In fact, this last approach rises to the level of “moderate certainty evidence.” So you can forget about the age-old “wet test.”

The biggest obstacle in attacking the running shoe-injury connection is an absolute lack of clear definitions to begin with. What constitutes a running injury? What makes one kind of shoe a “neutral shoe” and another a “hard midsole” shoe? Also, how do you “blind” subjects to the shoes on their feet? After all, most of us can tell the difference between a modern, high-stack super-shoe and a minimalist shoe.

So what should you do when it’s time for a new pair of shoes? The Cochrane authors don’t offer any advice; that’s not their job. They do have a few ideas for what future research is needed: More and better studies, particularly randomized trials. They’d also like to see explorations of “the influence of different types of running shoes upon injury rates in specific subgroups. More, including free full text of the “draft” document, at

How to get maximum mileage from your running shoes

Even if your shoes can’t prevent injuries, at today’s high prices, you’ll want to keep them clean and functional for as long as possible. Here’s a handy 5-step guide from Adidas that will work just as well on any other brand. I figured I’d be needing a used toothbrush, but had never thought of cleaning my shoes’ laces and inner soles. Most important: Keep your shoes out of the sun as much as possible. More at Adidas. Also, I have a very smart, tough, experienced marathon friend (who usually wins his age group at Boston) who swears that this “marine adhesive sealant” is the absolute best product for patching worn out soles.

Get hip about knee pain

Runners with knee injuries have been advised for quite some time to strengthen their hips (the abductor and adductor muscles). This strategy appears to be gaining more evidence. In a study of runners at the J of Clinical Medicine, researchers found that “the hip abductor muscles might play a bigger role in the pathophysiology of ITBS.”

A similar result surfaced in a randomized clinical trial of subjects suffering from knee arthritis. “It was shown that hip strengthening lowers pain while increasing function and quality of life and reducing drug intake. It also improved “performance based tests.” Both abductor strengthening and adductor strengthening worked equally well. More at Musculoskeletal Science & Practice.

Grass no easier on the legs than asphalt/cement 

Just about every runner I know believes in training on soft surfaces--like grass and trail--to lower impact forces and perhaps reduce injuries. Yet decades of research offer little to no support for this approach. Now a simple, clear new experiment has reached the same conclusion.

Grass? Cement? They’re about the same.

In this study, runners ran over a 50-meter track that included a grass section, a transition section, and a cement section. They wore devices that measured ground reaction forces and forces at the tibia. Result: The grass vs cement comparison did “not influence the impact loading during running.” 

Therefore: “Runners are encouraged to run on the surface they prefer.” I’ll add that preference isn’t the only important value here. There’s ease of access, time-management questions (if you don’t have to drive to a park or trail), tripping hazards related to the run surface, and type of workout, among others. More at Univ of Toledo.

The drip, drip, drip of new nutrition schemes

We all know that many athletes, recreational to professional, gulp various pills and supplements hoping for more endurance, muscle, recovery, and so forth. But somehow I missed a new trend: the use of intravenous infusions to reputedly achieve even more and better results.

Normally such “drips” are reserved for medical treatments such as anemia and severe dehydration after events like ultramarathons in the desert. And the Olympics bars intravenous infusions of more than 100 ml/12 hours unless they are a medical necessity.

Not that you should hook yourself to an IV drip any time soon. "There is no clear evidence that this works," said study author Charles Pedlar. "And on the contrary, there may be negative effects,” such as infection. More at U.S. News and the British J of Sports Medicine.

East African dominance is increasing

One of the things I’ve always appreciated about distance running is the low-cost factor. You should have the best shoes you can afford, yes. After that, who can say what’s the next most important item? The relatively low-entry economics of running is one reason, among many, that East Africans excel. 

A new paper investigates top half-marathon and marathon performance over the past 23 years, looking in particular for something called the “Matthew effect”--ie, the best get better, the less favored decline. It reaches several intriguing conclusions: First, top runners come from middle-income and low-income countries, not from the richest countries, as one might expect for many other sports like golf, tennis, swimming, etc. (This is less true for women, who are more often bound by cultural restrictions than men. Such restrictions are often more daunting in third-world countries.)

Second, Kenya’s share of top performances has risen from 47% to 50.8% in recent years, and Ethiopia’s from 22.4% to 38.2%--clear indication of a Matthew effect. In other words, the East African countries are poor on economics, but rich in running success, and getting richer.More at the J of Science in Sport & Exercise.

SHORT STUFF you don’t want to miss

> Whatta you know? Competitive weight lifters “taper” much like runners with a 43% decrease in volume

> 5 stretches to prevent and relieve low back pain

> In a RCT for weight loss, early time-restricted meals (from 7am to 3 pm) produced the best results

GREAT QUOTES make great training partners

“The men who learn endurance, are they who call the whole world, brother.” --Charles Dickens 

That’s it for now. Thanks for reading. See you again next week. Amby

P.S. Please share/forward this email to your running & fitness friends. They can sign up for the free newsletter HERE.