January 12, 2023

Time Restricted Eating leads to 8% faster times

Time Restricted Eating (TRE), and other intermittent fasting approaches, are a hot area in weight-loss research and book publishing. A few exercise studies have also looked into TRE’s effects on serious endurance performance. The most recent one produced an impressive positive outcome.

The subjects here were not runners, but cyclists of average age 52 who spent nearly an hour a day in the saddle during their normal training weeks--serious athletes. They performed a laboratory 10K time trial before and after 4 weeks on a TRE diet. After the diet, they covered the 10K almost 8 percent faster than before.

During the 4-week diet, cyclists were told to eat as much as they wanted of whatever foods they desired, with just one restriction. They had to limit their food intake to an 8-hour period, say 9am to 5pm. They self-reported eating as much as they did previously, only with the 8-hour limitation. They also continued training in their normal manner.

Results: They lost 5.3 lbs on average, all apparently from body fat, as their muscle mass did not decrease. Their blood pressure dropped significantly, and they burned more fat as fuel.

Of course, losing 5 pounds should improve endurance performance, as it did. Interestingly, since cyclists are supported by their bike’s frame and wheels, they are less affected by body- weight changes than runners. The study’s senior scientist said he would expect runners to improve more than the 8 percent recorded by the bicycle subjects.

Conclusion: “The benefits of 16:8 TRE seem to come from optimizing body composition without decreasing muscle. When combined with habitual endurance training, a 16:8 TRE protocol may enhance performance in middle-aged cyclists.” More at The J of Strength & Conditioning Research.


What running-shoe heel drop is best for you?

Slightly lost in all the discussion of minimalist and maximalist shoes is the role of “heel drop.” Heel drop is defined as the difference between the height of material under your heel and the same measure under your forefoot. For example, if your shoes are 30mm high under the heel and 20 mm high up front, they have a heel drop of 10 mm. You can think of this as an “inclined plane” under your feet, stretching from the toes to the heel.

The inclined plane can tip you forward a bit, or not at all if you have “zero drop” shoes. A shoe can also have a negative drop, tilting you backwards, but these are not popular among runners.

The amount of heel drop in your shoes can affect your running biomechanics and possibly your injuries. Quite a few running experts believe you should try higher-heel-drop shoes if you have Achilles and calf problems, and lower heel drops if you have knee issues. Here’s a succinct summary. More at Twitter/Doctors of Running.

Hard hill sprints can produce big performance gains

Okay, these guys were cross-country skiers, and not runners. But close enough. There are differences but also many similarities between distance running and XC skiing. As the authors of this paper noted: XC skiing requires a large aerobic energy contribution, with 70–95% of the total energy expenditure during competitions derived from aerobic energy sources. Sound familiar?

Subjects were highly trained national or international-level performers. The researchers wanted to figure out what particular type of training contributed most to their success. It turned out that hard hill training was a big factor. Conclusion: ‘These findings emphasize that high aerobic energy turnover to perform well in the uphill sections should be development-areas for improving skating time-trial performance in male skiers.” This sounds a lot like: Hard hill sprints can improve 10K run times. More at Int J of Environmental Research & Public Health.

Psych  yourself up for prime time success

We all know that we’ve got to be psyched up to perform our best on race day. You can’t just roll out of bed and … go! Another word for psyched up is “primed,” which is what researchers recently investigated with 90 athletes in their late 20s. About a third of them self identified as professional or semi professional.

In all, 89% used some kind of priming strategy, mostly alone but a few with a coach. Music was the top choice at 27% followed by instructional self talk (24%) and motivational self talk (23). Two thirds rated their main strategy as “very” or “extremely” effective. That is, they believed it had an important positive effect on race day. Priming strategies can get you ready for prime time. 

Conclusion: “Educating coaches and athletes on the implementation of priming techniques has its place when aiming to improve athletic performance.” More at J of Strength & Conditioning Research.

Don’t sweat a day or two of missed training

Everyone misses training days for one reason or another (injury, a wedding trip, a warm Island vacation, “the dog ate my training schedule”), and too many of us worry that these missed days will torpedo our training and racing goals. That’s possible, of course, if things drag on for week after week.

But most of the time it’s a needless worry. Here, two of my favorite running coaches, Jason Koop and Steve Magness, explain why you don’t need to freak out. In fact, many runners have found themselves stronger after a brief injury, because the enforced time-off was a recovery period they needed. More at Canadian Running.

How masters runners can slow down their “slow-down”

Here’s a sentence we can all agree with, from a recent paper: “Elite masters endurance athletes are considered models of optimal healthy aging.” The problem is, we still get older, and we still get slower year by year. Can anything be done about this?

Well, no. No one has yet figured out how to stop the aging process. But this “optimal healthy aging” paper notes that if you can maintain your training program through the decades, you can decrease your “slow-down” by about 50 percent. Not easy, I know, but every effort leads to some amount of reward. More at Int J of Environmental Research & Public Health (free full text).

The same topic gets a wide-ranging review at I Run Far with excellent advice from several top sources. Maintaining muscle mass through strength training gets several thumbs-up, but so does your attitude/mental outlook. Control what you can control, and don’t obsess about uncontrollable losses. Also: “Be here now.”

More for masters: Bump up the protein intake

An increase in protein intake might also help masters runners, according to a paper published last year. After looking at results from 58 experienced masters runners (average age, 58), the researchers concluded that “Protein intake is as important as carbohydrates during a marathon.” Also: “Higher protein intake is related to better marathon performance times.”

The authors believe this protein effect extends into the pre-marathon period as well. Conclusion: “Marathon-induced changes in body composition and metabolic blood indices are highly related to protein intake, either during the tapering period or during the race.” More at Nutrition.

Heating your muscles could also speed them up

Plunging into ice water, or maybe just a relaxed bath in the same, gets all the buzz these days, due in part to Internet sensation Wim Hof. And many runners use cold water immersion to speed recovery of their achy leg muscles. 

But there’s still a place for warm/hot water as well. This is particularly true if you like the sound of “water-circulating trousers perfused with warm water,” as described in the J of Applied Physiology.  

If that’s a bit much for your tastes, you might still want to try “passive heating” to tune up your muscles. Passive heating methods include a sauna or hot water, but a heating pad or other heat-transferring method might work as well. Results have generally shown that “An acute increase in muscle temperature by passive heating can increase the voluntary rate of force development.” Also: “Passive heating is an emerging and promising area of health treatment, and the effects of passive heating on muscle contractile function are an important subject for further research.” More at European J of Applied Physiology.

Intention to lose weight linked teen-runner injuries

Practitioners at a hospital based injury-prevention center decided to look back at conditions that might have caused running injuries among more than 130 teenage runners. Two factors stood out. Both had the same increased risk ratio of 4.58, and they were possibly related.The first, seen in many but not all injury studies, was female sex. The second, a newcomer to the injury-risk list, was “intention to lose weight to improve athletic performance.” Another important factor, with an odds ratio of 1.75, was “reduced weekday hours of sleep. 

Conclusion: “These intrinsic and extrinsic risk factors may represent targets for injury prevention for adolescent runners.” Without doubt, maintaining a healthy weight is crucial  to teen athletes’ health. Attempts to restrict diet for short-term success may also lead to injuries (particularly bone injuries) that could have negative long-term repercussions. Biology and social pressures make teen girls particularly susceptible. More at Journal of Sports Sciences.

[Also note the publication this week of Lauren Fleshman’s book, Good For A Girl. I’m 100 pages into Girl, and enjoying it greatly. Fleshman interweaves her personal running story with scientific reporting (and anecdotal dining-table scenes she witnessed) on the intense dietary pressures faced by teen and early-20s female runners.]

Finish line collapses look scary, but usually are not medical emergencies

Any time you’re watching the end of a big marathon, you’ll see a number of runners collapse just past the finish line. It’s a frightening thing, as the mind skips quickly to several worst-case scenarios. Is it a heart attack? Heat stroke? Hyponatremia? (The big marathon risks all start with “H.”)

Possibly yes, but probably no. These H conditions have been studied extensively, and they are very rare--much rarer than finish line collapse. Most finish line collapse is a result of what is now termed “exercise associated collapse.” EAC is considered “a benign condition”--not a threatening medical emergency. It results from a sudden drop in blood pressure when runners stop churning their legs after 26 miles, and also perhaps from some dehydration and other minor factors. Basically, the runner faints. 

What to do? “A simple treatment of oral fluids and assisted walking, where medical personnel walk collapsing runners in designated safe areas, reduces the incidents of medical interventions related to EAC.” Subjects may also be placed in a horizontal position to assist blood-pressure stabilization.

Marathon medical tents at the finish line have trained “triage” personnel to distinguish between low-risk collapses and those rare cases that require serious and significant medical attention. More at Stat Pearls Publishing

GREAT QUOTES make great training partners

“A bend in the road is not the end of the road… unless you fail to make the turn.”

– Helen Keller

SHORT STUFF you don’t want to miss

>>> Ketogenic diet might be good for healthy aging but not for top endurance performance

>>> Can you qualify for the 1003 club? (Lifting 1000 pounds in squat + deadlift + bench press, and running a sub-3:00 marathons.) 

>>> Thanks to great preventive medical, infectious disease at the Covid-delayed Tokyo Olympics was actually lower than at prior Olympics.

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