March 23, 2023

 Some running shoes claim a 4% boost. This one hits 11%

Sports scientists at Adidas headquarters in Germany recently decided it was time to answer an important question: What is the range of performance improvement in world-class runners when they wear different flavors of new super shoes? We know that shoes being advertised for a 4% advantage in running economy can produce a 2-3% faster race time. But who says that 4% is the limit?

That’s the subject investigated below, but here’s the really big question behind it: What if someone can design a pair of super shoes that are customized to the runner who’s wearing them?

If Nike’s not already doing this for its most famous runner, the Boston-Marathon-bound Eliud Kipchoge, I’ll eat a pair of carbon-plated running shoes for lunch.

In the new report, Adidas tested 4 different shoes on 7 top Kenyan runners. One of the shoes was a racing flat from the Dark Ages (5 years ago) and the other three were variations on Adidas super shoes the company is developing.

The Adidas test shoes produced a modest average improvement in running economy for the 7 runners, but one lucky guy got an 11% gain from one shoe. That would be roughly equivalent to a 7% improvement in a marathon time--from 2:10 to 2:00:55. (Note: Some of the super shoes led to worse performance for some of the runners. Be careful what you wish for.)

This means that if you tested Eliud Kipchoge in several different pairs of super shoes, you’d likely find one that seemed best “tuned” to his particular running. As I said, this has likely already happened. And will certainly happen more often going forward. More at Sports Medicine.

Does Time Restricted Eating hurt muscle growth?

Medical journals are spilling over with studies on the effects of Time Restricted Eating. Few apply specifically to runners or other endurance athletes, but here’s one that does. A group of male runners followed a normal diet and a TRE diet for 4 weeks, with a “washout” period between diets. Their caloric intake was the same with both diets. 

The main study goal was to check the runners’ ``cardiometabolic health.” It didn’t change between diets--a good outcome. However, the runners did lose more weight on the TRE protocol. That could be a good thing, depending on your goals and strategy. Conclusion: “TRE is not detrimental to cardiometabolic health in endurance-trained male runners but could be beneficial on exercise performance by reducing fat mass.” More at Nutrients (free full text).

Another TRE study on older men and women (65-74) found that both sexes lost significant weight and visceral fat on a 6-week TRE diet, which was easy to follow for 98% to 99% of subjects. More at Experimental Gerontology (free full text).

Given some of the positive results associated with TRE, especially weight loss, a crack research team thought someone should answer an important question: What about protein mobilization? It wouldn’t be good if TRE also caused a potential loss/lack of muscle health by lowering protein availability.

But it doesn’t seem to, at least not after 10. Conclusion: “Short-term TRE does not impair rates of muscle protein synthesis in adults with overweight/obesity.” Still, more work needs to be done over the long term to make sure “TRE-induced weight loss can be achieved without compromising muscle health.” More at Obesity (free full text).

“The hills are alive” … with super training results.

The below article describes the first randomized, controlled test of hill running vs flat running for their effects on vo2 max, heart rate, lactate, and perceived exertion. Subjects were well trained (over 40 miles/week) female and male runners who were asked to run 4 x 5-minute repeats (with only 90 seconds of recovery) at their “maximal sustainable intensity.”

All the testing was done on a lab treadmill. Each subject performed one set of repeats at a 1 percent incline (“flat”) and another set at an 8 percent incline. The results showed no difference in heart rate, lactate accumulation, or perceived exertion.

But wait. That’s not the whole story. On their hill efforts, runner-subjects spent 42 percent more time over 90% of vo2 max than on the flat. (A similar test with cyclists has produced similar results.) “Therefore, superior performance adaptations could be assumed via uphill HIIT.” 

However, such real-world results have not been demonstrated yet. Another positive for hill running: Many consider it less likely to cause injuries. Of course, hill running is also slower than flat running, so you still have to do some amount of faster training on the flats.  

In this case, the researchers concluded: “Uphill running during HIIT sessions appears to be an effective alternative to traditional horizontal HIIT sessions.” More at Frontiers in Physiology. 

The truth about all those vaunted breathing techniques, devices, and supplements

Here a top group of experts, including a RLRH favorite, Nick Tiller, investigated a wide range of techniques, devices, and supplements that claim to improve your “respiratory function,” ie, breathing.

While this is not a sports performance review, it does note which approaches, “from the reasonable to the absurd,” could have a positive effect on performance. Here’s a short summary..

Vitamin C: “Acute supplementation may benefit individuals undergoing periods of extreme physical stress. An analysis of five trials comprising marathon runners, skiers, and soldiers, found that vitamin C supplementation reduced symptoms of the common cold by ~ 50% following ‘severe physical exercise.’ "

Nasal dilators: “Most studies show no effect of nasal dilators on cardiorespiratory function or ratings of perceived exertion during exercise, no effect on exercise capacity, and no effect on physiological variables during the acute phase of recovery.”

Respiratory muscle training: “If applied with the appropriate frequency, intensity, and duration, RMT can improve specific aspects of respiratory muscle function (e.g., strength and endurance). There is convincing evidence of an ergogenic effect of RMT in healthy individuals (athletes and non-athletes).”

Nasal breathing: “Nasal breathing is feasible during submaximal exercise and even maximal exercise after extensive habituation, but there is little-to-no data supporting a subsequent benefit on exercise capacity in healthy individuals.”

Omega 3 fatty acids: May limit problems associated with exercise induced bronchospasm.

Probiotics, prebiotics: “Daily probiotics and/or prebiotics reduce the incidence of upper-RTI [infections]  more than placebo in adults, children, active individuals, and athletes.”

L menthol (mint, peppermint): “May translate to improved exercise performance in the heat.”

More at European J of Applied Physiology (free full text).

A separate paper on nasal dilators performed a meta analysis and systematic review of their effect on runners. “There was a difference in favor of the nasal dilator when compared to placebo for maximal oxygen uptake and rating of perceived exertion.”  But the “certainty of the evidence was very low.” More at Journal of Sports Sciences.

How far should you run at “marathon pace” in training?

In their marathon buildup period, most marathoners do a certain amount of running at their goal marathon pace (MP). That’s the very definition of “specificity of training.” Of course, if you wanted to be 100% specific, you’d do 26.2 miles at MP, and no one does that (I hope).

So the question becomes: What’s the longest, most productive MP run you should do while training for a marathon? On this message board, the respondents offer a range of options, most falling at the lower end of the 8- to 16-mile distance. The simplest long-run workout is probably: 10 miles easy/10 miles at marathon pace. 

A few believe it’s even better to do long runs interspersed with 1-mile repeats at half-marathon effort.

These follow the system of a successful Kenyan coach, and are said to improve your lactate clearance. More at Reddit.

3 ways tuneup races can sharpen you for the big time

There are a lot of different opinions about how and when to utilize shorter-distance races during a marathon training cycle, or even whether to use them at all. Chris Lundstrom, coach of the Minnesota Distance Elite squad, sees three variations on a theme.

 

You can ”Race with a taper.” This will supply the “single best training stimulus available.” 

You could also “Race Without A Taper,” which will simulate the tired feeling of a marathon. But this approach has risks: injury, overtraining, and the mental challenge of dealing with a possibly poor performance.

You might try “Running Goal Marathon Pace,” usually in a half-marathon tuneup. A potential pitfall: Many “find it difficult to stick to the plan, and get carried away by the excitement of the event,” which overturns the most basic tuneup rule: It’s prep, not a race. Lundstrom works around this by telling athletes to run the first 9-10 at marathon pace then close faster if they feel good.

He doesn’t say that one of these strategies is better than the other. All can be useful, so long as they meet your needs, and you stick to the plan. More at Fan Hub TF.

Don’t let procrastination torpedo your goals

Just about everyone thinks that procrastination gets the better of them from time to time. It’s so much easier to put things off than to get them done. But it could be life-changing to make a small dent in your procrastination tendencies.

Running coach and all-around performance coach Steve Magness says it’s not a time management issue as many would observe, but one of “emotion regulation and expectations.” He follows up with 6 strong tips to help you move the needle. 

I was struck by number 2: “Learn how to turn the dial.” In other words, there’s a time to relax, but also a time for getting stuff done. Breathing techniques, music, coffee, self-talk and other strategies, can turn the dial up or down. The rest is on you. Figure out which ones to use, and how, when you want to power through to your goals. More at Twitter/Steve Magness.

Sodium bicarbonate: Worth the risk?

A few  years back, a new gel appeared on the endurance market. It claimed that it allowed big carb intake without the GI issues that often accompany carb intake in marathon runners. Alex Hutchinson was skeptical at first, but he kept following research results, and eventually came around to believing in the product, made by Maurten.

Now Maurten says it has solved the baking-soda problem. What’s the baking soda problem? The cheap and common kitchen product is known to improve performance (mostly in shorter, high-power events, but that could be changing), and also to produce serious stomach upset. That has made it a non-starter for endurance athletes.

Maurten now tells Hutchinson it has developed a hydrogel-baking soda product that is being used with great success by world class athletes. It’s a fascinating tale that will become much more credible when research studies confirm it. More at Outside Online.

The bizarre stride that finished 100 marathons in 100 days

Runners who spend a lot of time on the ground are said to have a high “duty factor.” Their style is sometimes called “Groucho running” due to the extreme knee bending. These runners will never win a beauty contest or the Olympics. But they can be effective in modest-pace endurance running.

Here researchers followed a 100-day marathoner who was 55, stood just a tad under 6 feet, and weighed 202 at the beginning of his quest. He finished his marathons in an average time of 4:30, and took about 164 strides per minute. Most remarkably he spent more than 4 times as much time on the ground vs his “flight time.” A comparison group of rear footers had a 2:1 result for this ratio.

You might have expected this runner to adapt a forefoot or midfoot stride, since they generally reduce impact forces. But, no, he did it his way, and everything turned out fine.

Our 100-day marathoner completed his challenge without getting injured. Along the way, he lost approximately 15 pounds (entirely from fat), while slightly increasing his muscle mass and his bone mineral content. The latter are not easy to do during weight loss, and testify to his overall body health despite averaging 183 miles per week for 14 weeks. More at Journal of Sport & Health Science.

SHORT STUFF you don’t want to miss

 >>> Stretching the truth: Stretching for runners continues to be a highly debated topic.

>>> Boost your immunity: In RCT, post-workout protein/carb beverage beats carbs only.

 >>> Another good reason to sleep well: Insomnia linked to increased heart deaths.

GREAT QUOTES make great training partners

“The secret of getting ahead is getting started.”

--Mark Twain

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

March 9, 2023

 The craziest training program ever to produce a marathon world record

In December, 2018, 70-yr-old American Gene Dykes stunned the marathon world by breaking the age-group record of the legendary Ed Whitlock. Dykes ran a 2:54:23 in Jacksonville, FL. A little more than 3 years later, Dutchman Jo Schoonbroodt, 71, took 4 seconds off Dykes’s mark at the Maasmarathon in Belgium.

And he did it with a training program that seems to have broken all the rules.

But first, a little background. A year after Dykes ran Jacksonville, the New England Journal of Medicine (free full text) published a Letter describing the outcome of laboratory testing on Dykes. Last week, Frontiers in Physiology published a much deeper investigation (link below) of Schoonbroodt’s training and physiology, and directly compared him with Dykes. The contrasts are startling, and perhaps illuminating (Though one can never extract too much meaning from these one-off “case studies.”)

Here’s the “tale of the tape” as comparisons between boxers used to be termed. The two runners weighed almost the same (142/143 pounds). Both were a little taller than I would have expected at 5’ 11’ (JS) and 5’10” (GD). They had nearly identical vo2 max results, 46+ ml/kg/min. Dykes was substantially fatter at 19% body fat vs Schoonbroodt’s 13.6%.

(Medical studies don’t use subject’s names, but they are allowed to say things like “broke the record for the 70-74 yr old marathon in May, 2022.” So it’s not hard to deduce who’s who in these reports.)

Treadmill testing revealed modest differences between the two runners, primarily that Schoonbroodt was about 8% more economical than Dykes. Then again, he wore super shoes during the treadmill testing, and Dykes didn’t. (Both wore super shoes in their record-setting races.)

What made Schoonbroodt more economical? There’s no sure answer to this question, but that didn’t stop researcher Bas van Hooren (himself a 28:41 10K runner) from speculating. He was no doubt emboldened by the rather remarkable 7-plus years of training information that Schoonbroodt provided. This data was backed up by his Strava-logged runs, plus 3 weeks when he wore a heart rate monitor provided by the researchers.

In 2015 Schoonbroodt ran an average of 49 mi/week, which he increased to 58 the next year. Then he got down to work. By 2021, he was logging 83 mi/week. Sounds nasty, right? But quantity means little without a quality factor, and Schoonbroodt was chugging along at a pedestrian 11:30/mi pace. Despite the slow training, he ran his record-setting marathon the following May at 6:39 pace.

A zone by zone analysis of Schoonbroodt’s training found him in Zone 1 for 97 percent of his running. He had no injuries during this period. By comparison, Dykes reports that he was running 40 to 50 miles per week during his buildup to Jacksonville (along with an amazing number of ultra races on weekends.)

Can we draw any conclusions from this side-by-side comparison? Van Hooren writes: “The better running economy [of JS] is likely a consequence of an almost double weekly training distance.” He also has a very high percent of slow twitch muscle fibers--over 90%. Dykes has not been tested for fiber types.

This paper adds to a preliminary amount of research suggesting that top age-group marathon runners maintain performance more through high-mileage training (even if at a slow pace) rather than high-intensity training. More at Frontiers in Physiology (free full text).

How do you know when you’re training too hard?

We all want the same thing from our training. We want to train hard enough to produce a genuine impact on our fitness and performance. But we also want to avoid overtraining, since this could send us spiraling in the wrong direction, ie, downward. The question is: What’s the best way to find the red line without going over it?

There are different methods, of course. Heart rate. Fluctuations in weight. Various systems that attempt to measure training load or training stress. Power output. Perceived exertion. And more.

A team of Dutch exercise physiologists decided to dig a little deeper into this issue. They asked a group of “recreational cyclists” to do 4 different workouts, immediately followed by a 3km time trial. (Earlier they had done a similar time trial while fresh.)

The study team monitored their subjects with several of the above mentioned systems (heart rate, etc) to see which most accurately reflected fatigue as measured by performance-loss in the time trial. In total, they analyzed 7 systems--4 related to heart rate, 2 related to power output, and one related to perceived exertion.

And the winner? ”Perceived exertion was the only one in line with the acute performance decrements found in this study.” In other words, while you might find it ever so tempting to rely on an objective, probably digital reading of your fatigue (such as your morning heart rate), there’s a better way. Substantial evidence supports the usefulness of relative perceived exertion. Listen to your body. And believe it. More at International J of Sport Physiology & Performance.

While we’re on the subject, here’s a great “hack” to avoid overtraining

Gordo Byrn is a former winner of the Ultraman Hawaii championship that covers 320 miles of swimming, cycling, and running (52.4 miles) in 3 days. He trained hard to achieve this, and made a lot of mistakes along the way. Over-training was one of them.

As a result, he eventually created a “rule” to make sure he never went over the edge again. It’s one I haven’t heard before, but I like it, because it’s easily stated, and should be quite effective. 

Here the rule: Every week should include at least two easy days back to back. Not one. That would be the traditional hard/easy approach, and it can be pushed too far. But two easy days: hard/easy/easy. 

This gives you a lot more safety margin against overtraining. More at Feel The Byrn.

What to eat just before bedtime

Just about everyone I know is trying to reduce their post-dinner snacking and calorie consumption. Even if you’re not on a Time Restricted Eating program, you’ve probably gotten the message that consuming extra calories before a long period of inactivity (like sleep) can send your blood glucose out of control. On the other hand, moving right after eating helps control glucose.

But there might be an exception to this nighttime snacking rule for hard-training athletes. A new RCT study has shown that consuming 360 calories of a whey-casein protein snack before bedtime “increases both mitochondrial and myofibrillar protein synthesis rates during overnight recovery from exercise.” 

The study began when the 36 male subjects completed an hour of endurance exercise in the lab 4 hours prior to their bed time. Then, just before sleep, they slurped down a whey or casein protein drink, or a noncaloric placebo drink. Both protein drinks “resulted in greater mitochondrial and myofibrillar protein synthesis overnight when compared with placebo.” The whey and casein proteins produced similar results--neither was better than the other.

The implication here is that a pre-sleep protein drink could increase all the other good things that happen when you are asleep. You get training adaptation, and recovery. More at Sports Medicine (free full text).

A pain paradox. But true. And it feels so good

There was a time when runner’s high was regarded as a quasi-mystical, zen-like state that some athletes experienced while running. Now it’s more often seen as a condition that results from the release of endocannabinoids in the brain. That is, it’s not so much mystical as biochemical.  

The release of these “eCBs” is believed “to alleviate pain, induce mild sedation, increase euphoric levels, and have anxiolytic effects [anti anxiety effects].” In our stress-filled world, many find these an important reward for their running. More at International J. of Molecular Sciences (free full text).

There’s also new evidence, from a study of more than 31,000 individuals, that those who exercise regularly report “lower odds of experiencing pain” in their daily life. In fact, they were only half as likely to report pain as low-level exercisers. This means that regular exercise is a “potential risk factor for minimizing development of chronic pain.” Nice. I’ll take it. I especially like that it’s opposite to the “exercise produces pain” belief that many mistakenly harbor. More at Medicine & Science in Sports & Exercise.

The truth about caffeine and fat burning

No one doubts that caffeine improves performance. It’s on virtually every list of ergogenic performance boosters compiled by endurance experts. (And these lists are very short.) The question that remains is mainly one of mechanisms--how exactly does caffeine work?

Decades ago, an early stab at the answer suggested that caffeine enhanced fat burning during endurance exercise, which could “spare” glycogen, and thereby extend endurance. More recently, this theory has been largely replaced by an emphasis on neurotransmitter effects or central nervous system effects, ie, reducing perceived exertion.

However, the fat burning hypothesis survived this new meta analysis and systematic review of 94 studies. It concludes that caffeine has a “highly significant effect” on increasing fat metabolism. “Therefore, the fat metabolic theory for CAF for exercise (and rest) remains viable based on this systematic review of the literature and meta-analysis.” More at International J of Sport Nutrition & Exercise Metabolism (free full text).

What female runners should do to prevent knee injuries

Knee injuries are a major concern for runners, and females are often found to suffer these more often than males. That has led some to conclude that females have weaker quad muscles that may not stabilize the knee while running.

However, this study didn’t find that to be the case. It used a “a 2D patellofemoral joint model” that looked at “estimates of quadriceps muscle force and sex-specific patellofemoral contact area.” The females didn’t appear to have weak quads but rather peak hip adduction and internal rotation angles during running that were greater than males. This means that strength training of the hip muscles--adductors and abductors--could prove useful in preventing knee injuries. Other studies have reached a similar conclusion. More at International J of Sports Physical Therapy (free full text).

When to consume “energy drinks” or shots, and when not to

The International Society of Sports Nutrition has updated its Position Stand on energy drinks (ED) and energy shots (ES). In all, the new stand includes 13 key points. Here’s my brief summary.

EDs and ESs can improve performance, mainly through the use of caffeine and carbohydrates. Most of the other stuff dumped into ED and ES has little to no effect. There is “limited evidence” that low calorie ED and ES could provide “enhanced training capacity,” but be careful not to consume higher calorie doses that could add weight. ED and ES “are not recommended for children aged 2 to 12,” and adolescents aged 12 to 18 should “exercise caution and seek parental guidance” when considering ED and ES. Diabetics and those with cardiac concerns should speak to their physician. Indiscriminate use of ED and ES, including multiple servings a day along with other caffeinated beverages “may lead to adverse effects.” More at the International J of the International Society of Sports Nutrition (free full text).

SHORT STUFF you don’t want to miss 

>>> Leg muscle engagement little different between treadmill and over-ground running. Free full text.

>>> Young runners respond to “extrinsic motivation” (friends and social relationships) to stick with running, but masters athletes use intrinsic factors like challenge and self-competition.

>>> Ear’s a surprising development: South Korean biomechanics specialists have invented an earbud that provides stride-analysis data. (Not yet available outside So Korea and Japan. But an interesting approach.) Free full text.

GREAT QUOTES make great training partners

“I’ll be happy if running and I can grow old together.”

--Haruki Murakami

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