Feb 23, 2023, "Run Long, Run Healthy"
In breakthrough study, low-carb diet supports high-intensity running
A large group of exercise researchers who are strong proponents of low carb, high fat diets (LCHF, Ketone) for athletes have published a study that appears to support what they have long proposed. After 31 days on a LCHF diet, their male subjects were able to complete a 1-mile time trial and a tough interval workout (6 x 800 meters) with results similar to when they were following a high carb, low fat (HCLF) diet.
Classic diet and exercise theory predicts that it should be difficult or impossible to do such high-intensity running (at 85% of vo2 max) without a high carb diet. Here, after a full month to adapt to the new diet, the runners did achieve the desired result. The study did not include an endurance component to test if the runners had enough glycogen to complete several hours of running at a relatively high intensity like marathon pace.
The authors, including big LCHF supporters like Tim Noakes and Jeff Volek, concluded that their results “challenge whether higher carbohydrate intake is superior for athletic performance, even during shorter-duration, higher-intensity exercise.” They also found that a LCHF diet could protect some pre-diabetic runners from developing full-on diabetes. The LCHF diet did, however, raise cholesterol levels somewhat.
The 10 subjects were all “middle-aged competitive distance runners” logging at least 20 miles/week and capable of breaking 7 minutes in the mile. They followed both a LCHF and HCLF diet for 31 days with a washout period between the two, month-long diets. The LCHF was approximately 64% fat and the HCLF diet about 18% fat.
The LCHF diet produced double the weight loss of the HCLF diet, 5.3 lbs vs 2.2 lbs, even though both diets contained the same number of total calories and the runners were told to maintain their usual training load. After the diet periods, both groups completed a 1-mile time trial in about 6:00 to 6:15, and both did the 6 x 800 workout in an average of 2:31 per 800. Towards the end of this workout, runners on the LCHF diet “achieved the highest rates of fat oxidation yet reported.”
Conclusion: “These results: (i) challenge whether higher carbohydrate intake is superior for athletic performance, even during shorter-duration, higher-intensity exercise; (ii) demonstrate that lower carbohydrate intake may be a therapeutic strategy to independently improve glycemic control, particularly in those at risk for diabetes.” More at Frontiers in Nutrition (free full text).
An unrelated article based on new research explains that ketone mono esters may boost EPO in the blood. The article concludes: “Does supplementing with ketone esters increase red blood cell mass and longer-term performance? The future of research on ketone esters for human health and performance looks interesting.” More at My Sports Science.
Do super shoes cause injuries?
This new paper raises a question of major interest to today’s runners and coaches: If someone wears super shoes in training and racing, are they more likely to get injured? Since the paper is authored by some of the top running injury experts in the U.S., it’s important.
But first, let’s be careful about what the experts are presenting here.They’re not offering any data at all, and they’re not claiming that super shoes increase injury risk. Instead they’re discussing “a possible association between bone stress injuries and carbon fiber plate footwear.” This isn’t much different from discussing the fact that running of any kind in any footwear (or without) causes injuries.
Basically the paper presents a handful of case studies of “highly competitive” junior-age track runners and older road runners who “developed acute pain during or after running in carbon fiber plate” shoes. The pain came from navicular stress injuries the runners developed. (The navicular bone is located in the midfoot area.) The authors also argue that “it is plausible that shoes with compressive foam midsoles” could lead to such injuries.
They conclude by noting that special “strategies may be required to reduce risk of injury due to altered foot and ankle mechanics” of those wearing super shoes. They wish to “raise awareness on possible health concerns around the use of carbon fiber plate footwear” and “to suggest a slow gradual transition from habitual to CFP footwear.” More at Sports Medicine (free full text).
Achieve your racing goals with this ultimate training guide
Here’s a flat-out great Training infographic that you need to bookmark right now, or print out for your refrigerator, or pin to your bulletin board. (I’ve done 2 of the 3.)
It will help you bridge the terminology confusion that swirls around training zones, paces, perceived efforts, lactate thresholds, heart rates, and more. Basically, it’s a one-step resource that shows you how to visualize and comprehend how various training concepts and lingo (and we have too much lingo) relate to one another. With this guide, you can train simpler and more effectively. More at Twitter.com/Daniel Moore who admits he borrowed several data points from Alan Couzens.
How Camille Herron sets ultra records without long runs in training
U.S. ultra runner Camille Herron, who describes herself as “propelled by tacos and joy,” set a new world and american record for 100 miles on the track last weekend. She clocked 12 hours, 52 minutes, and 50 seconds for the distance. That’s 7:43/mile for 402 laps on a track. And yet she says “Long runs are overrated.”
Before she turned to ultras, Herron often did 26-mile training runs or back to back long runs. Now she has changed that routine. She prefers to run often, usually twice a day, but not as long, and not as hard. The switch was “like a rocket to the moon,” she says. Her performances took off.
Now she’s “totally fine doing two hours as my long run,” She’s also getting stronger and faster at age 41. Musculoskeletal researcher Karen Troy thinks Herron’s system works because it stresses the skeletal system without over-stressing it. The training aligns “well with a lot of theory,” Troy notes.
Another ultrarunning champ, Sabrina Little, has followed a similar pattern. She used to include workouts like 30 miles one day, and 20 the next. Now, with children, she has to do smaller chunks. “Breaking things into shorter blocks was beneficial,” Little says. “I was able to do higher integrity work instead of just long, slow distance.” This helped her set an American record for the 24-hour run.
Herron includes runs with lots of different stresses in her training, particularly uphill and downhill running. “The body responds to change and dynamic stimuli, so you need to stress the body in different ways.” More at Trail Runner.
How to perform your best under pressure
The ability to perform optimally under pressure is critical across many occupations, including the military, first responders, and competitive sport. It’s kinda the name of the game, after all. Whether you're aiming for the Olympics, a Boston Marathon qualifier, or your first 5K finish, you gotta pull your game together on race day.
To learn how successful athletes do this, a research team gathered together 68 experts from four main fields: the defense industry, competitive sports, high-stakes civilian life, and performance neuroscience. The experts then began discussing their top beliefs, eliminating those that did not have broad support, and holding onto those that did.
Eventually, they whittled things down to 10 major factors: (1) Attention; (2) Cognitive Control—Performance Monitoring; (3) Arousal and Regulatory Systems—Arousal; (4) Cognitive Control—Goal Selection, Updating, Representation, and Maintenance; (5) Cognitive Control—Response Selection and Inhibition/Suppression; (6) Working memory—Flexible Updating; (7) Working memory—Active Maintenance; (8) Perception and Understanding of Self—Self-knowledge; (9) Working memory—Interference Control, and (10) Expert-suggested—Shifting.
They seemed particularly intrigued by (8) Self-knowledge, because nearly everyone agreed about its importance, but it has been little studied by researchers. This means there’s potential for future research on self-knowledge that “could change the landscape of the performance field.” More at Frontiers in Psychology.
Should women train different than men?
It’s a good and important question, and one for which a good answer does not exist at present. The paper published below makes a modest first step. It looks specifically at female vs male ultra runners, but the main points could be extended to any endurance training.
First point: Women are not men, and most training studies have investigated male response to training. Second, women are known to be different from men in a number of key areas: size, strength/muscle, menstrual cycles, bone stress and athlete triad, oxidative response, and perhaps superior fatigue resistance.
Thus: “When considered as a whole, the body of research currently suggests that sex-specific recommendations and guidelines could improve performance and health outcomes in female ultramarathon runners.” Unfortunately, there’s not enough evidence to actually formulate different training guidelines. That will depend on future research. However, the evidence base is currently insufficient to formulate such guidelines, and further research that recognises sex as an important bivariate measure is required. More at Sports Medicine-Open (free full text).
If you’re interested, here’s a deep review of male vs female differences in strength, endurance, and much more. It concludes than men become “notably stronger than female subjects around age 15,” that the biggest differences are in the upper body, but women “experience greater relative strength improvements” and lower muscle injury rates. More at Journal of Strength & Conditioning Research (free full text).
Also, an Australian woman, Erchana Murray-Bartlett, ran a marathon a day for 150 days. That’s real endurance. More at Canadian Running.
Stay injury free: Avoid these 7 common mistakes
A physical therapist who specializes in endurance sports reflects on the kinds of running injuries he sees too often in his office. And why/how they develop. Then he offers the best ways to “fix” each of them to avoid future injuries.
I liked his handy Relative Perceived Exertion chart filled in with examples of efforts 0 thru 10, and the good advice about understanding pain, and how to react to it. More at Outside Online.
Largest study ever concludes exercise good for depression
We all know that we feel better and more energized after running, and we have all read that vigorous exercise can reduce the effects of depression--a major mental health issue affecting 300 million people worldwide. But is this really true? And how strong is the effect of exercise on depression?
A new paper presents itself as the most thorough to date, consisting of a “systematic review and meta-analysis with meta-regression.” It reviewed the effect of exercise in depression from 41 studies that included 2,264 adults suffering from “major depressive disorder.”
The main finding: Exercise had “a large effect favoring exercise over control conditions.” It was roughly as good as psychotherapy, helping one out of every 2 individuals. Also important: Exercise works for those who refuse or can not tolerate medication and/or therapy. Both light exercise and more vigorous exercise seem to work. More at British J of Sports Medicine (free full text).
SHORT STUFF you don’t want to miss
GREAT QUOTES make great training partners
"To climb steep hills requires a slow pace at first."
--Shakespeare, Romeo and Juliet