March 30, 2023

Welcome to the free, but abridged edition of "Run Long, Run Healthy" for March 30, 2023.

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Psst! We have a world record holder in our midst

I hope this doesn’t amount to a privacy violation, but I’ve shared beers with Camille Herron, and I’m hoping she won’t mind. Last weekend in Australia, Herron set a female world record for the 48-hour run as she covered 270.505 miles. This also made her the only American female to hold a distance record superior to the best American male--a neat asterisk.

Herron holds many other records as well, and is a longtime reader of RLRH. Congrats, Camille! Keep running long and healthy. More at Outside Online.

Will you run faster if you lose weight?

These days it’s practically verboten to speak/write about weight loss among endurance runners. Only a few top researchers manage to explore both sides of the question in an open, honest manner.

Australian sports nutritionist Louise Burke qualifies as one of those “top researchers.” She’s also a serious long time marathon runner. That helps her produce insightful work. She knows how endurance athletes think, and the ways they eat and train. 

Here, she tackles one of the biggest questions every runner has: Should I lose a few pounds? Will it help my performance or hurt it?

Burke is fully aware that adolescent athletes, particularly females, might face short- and long-term harms (including bone injuries) by weight-cutting. She quotes “expert opinion that Low Energy Availability can be associated with a variety of health and performance concerns.”

On the other hand, a lot of midlife runners could improve their endurance times by dropping 5 to 10 pounds. And Sweden’s Hans Smeets became a world-record-setting 1500-meter runner at age 75 after shedding 15 pounds (research here and personal communication from Smeets).

In this trial, Burke and colleagues divided elite race walkers into two matched groups of about 10 walkers apiece. While continuing their hard training (70 miles a week of running and race-walking, plus additional cross-training), one group maintained its normal high-performance diet for 9 days (consuming 3660 calories/day), while the other group cut back to 2170 calories. During this time, the first group lost about 2 pounds while the second group lost 4.4 pounds.

Both groups then consumed a high-carb diet for 24 hours before racing a 10K time trial. This equal carboload presumably excluded low glycogen as a variable in the outcome. It centered attention on the subjects’ changed body weights.

Result: There was essentially no difference in time trial performance between the two groups. This occurred despite the fact that “the physics of movement in running events show theoretical and empirical support for the benefits of a lighter body mass.” The researchers had hypothesized that the low cal group would “achieve similar (or even superior) benefits.”

Why didn’t they? Perhaps because the low-cal athletes registered higher-stress and less recovery on a Stress Questionnaire. Every day, scientists are believing more strongly that our mental-emotional state has direct physical effects. 

All the same, Burke et al don’t dismiss the potential for intelligent weight adaptation. They state: “A series of strategically timed but brief phases of substantially restricted energy availability might achieve ideal weight as part of a long term periodization of physique by high performance athletes.”

In other word: Your training follows a pattern of hard weeks followed by easy weeks, so that you don’t overtrain. You could possibly do the same with calorie restriction. However, be careful not to drift into months of insufficient energy intake.That will have an impact on both your performance and your health.

Finally, “The relationship between body mass, training quality, and performance in weight-dependent endurance sports is complicated.” Note that sports like running and race walking are weight bearing, whereas swimming, cycling, and rowing are quite different. This changes the calculus of weight gain and loss. More at Medicine & Science in Sports & Exercise.

Hop to it, and run a faster 5K

The last several years, I’ve attempted to improve my rope-jumping skills every spring. I thought the lower-leg training might help me run better. But I never got very far. Didn’t have any skills. This year I think I’ll switch to just basic hopping without the rope. Maybe I’ve got enough talent for that. 

Here, German researchers assigned recreational runners to 6 weeks of “hopping exercise” in a randomized, controlled trial. The runners did only 5 minutes of “double legged hopping” daily, starting with just 10 continuous seconds at a time, followed by a rest period. Over the 6 weeks, they gradually increased the length of each hopping repeat.

This wasn’t simple hopping. I probably would have called it “explosive jumping.” The instructions: “Hop as high as possible with both legs, keeping the knees extended, and aiming to minimize ground contact time.”

At any rate, the hopping worked. It increased running economy (but not VO2 max), and didn’t produce injuries. Conclusion: “This study provides the first evidence that 5 minutes of daily hopping improves RE at moderate and high running speed.” Me? I’m going to start with gentler hops. More at Nature (free full text).

Do super shoes prevent injuries? Or cause them?

Here’s an excellent article on the debate over whether or not super shoes might increase injury risk. There’s good evidence the shoes can make you faster, and they might do this in part by changing the way your feet and lower legs function on the road. This could be good, of course. Many coaches and athletes feel that the shoes “save” a runner’s legs, allowing more and harder training, with less recovery.

However, if your legs are functioning in a novel manner, this could lead to overstress injuries. What’s the best approach? You’ve heard this one before: The experts all suggest a gradual transition to your use of super shoes. More at Live Science.

Also, this podcast interviewed two experts who have done research with super shoes. The “show notes” are so complete that you don’t have to listen to the 66-minute pod. The notes discuss how slower or lighter runners might get less “return” from super-foam shoes than faster/heavier runners, and explore the debate about injuries. More at Scientific Triathlon.

SHORT STUFF you don’t want to miss

>>> Not a surprise: Trail runners must be mentally tough and resilient.

NOTE: If you were a subscriber to the complete, full-text version of RLRH for $4/month, you would also have received new articles about:

# Staying fast through the years … and decades

# Increasing your long-run distance (without getting injured)

# Reasons to be skeptical about minimalist shoes

# How running increases your personal happiness

# Why Jakob Ingebrigtsen says: “Training doesn’t have to be brutal.”

# What’s your maximal heart rate?

# Movement is medicine, so take your pill every day

# Going for it! With an inspiring quote from Lin Manuel Miranda

Click here for details about subscribing to the complete, full text edition of “Run Long, Run Healthy.”

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