June 1, 2023

The best pace strategy (and gel plan) for your next marathon

From this new report I learned that differential equations run faster with ever-higher consumption of carbohydrate gels, but people don’t. Actual people like you and me stumble to the sidelines and puke when we take in too many carbs on the run.


All joking aside, this is a cool paper. How can you not love a research group that says “Our overall goal is to determine the best nutrition and pacing strategy to use when running a marathon (or other long distance race) in order to finish in the shortest amount of time.” That’s your goal, too.


The study authors didn’t attack the problem in the usual manner--by measuring runners in the lab or in actual racing conditions. Rather they strung together a bunch of equations that modeled what happens when runners race at different speeds with and without taking carb-energy en route. 


And their math seemed pretty good. When they compared it to Eliud Kipchoge’s actual 1:59:40 marathon, they arrived at a 1:59:09. That’s only one second per mile different from Kipchoge, or 0.4%


So much for the math. What you really want to know are their suggestions about race-pacing, and carbohydrate gel ingestion for your next marathon. To begin, run even pace through. Always. 


Next, they say that taking five 100 calorie carb gels could help you run 7.75% faster. That’s a big number--roughly 14 minutes for a 3-hour marathoner, and 18 for a 4-hour.


If you can’t manage 5 gels, 4 is a good target. Conclusion: “We found that the optimal trajectory for marathon runners was to run at a steady state velocity for the majority of the race and take in at least four 100 calorie supplements spread evenly throughout the event.”


They also fed their equations 11 gels, and 24 gels. The equations appreciated the extra energy, and “ran” faster. You and I would likely have different reactions, which the researchers understood. They stated that consuming 11 or 24 gels would “most certainly upset the runner's stomach and all of those carbohydrates would struggle to make it to the muscles due to imbalances in the stomach. The body does not handle the amount of accumulated energy in the nutrition compartment without a negative reaction.”


That’s for sure. More at Frontiers in Nutrition with free full text.


Creatine is proven to build power. But what about endurance?

Creatine is one of the oldest supplements around, but it seems to be enjoying a bit of a renaissance lately. This has happened mainly because of a positive review paper in the The Journal of the International Society of Sports Nutrition (free full text). Also, the first author of that paper, Scott Forbes, has been making the rounds on several popular podcasts.


Not that anyone has ever doubted that creatine can boost strength and power. We just doubted that it could do much for weight-bearing endurance athletes like runners and cross-country skiers. Forbes argues that it can, but primarily in the context of ultra-competitive events like an Olympic final where frequent pace surges are commonplace. 


That wouldn’t seem to apply to steady-pace events like a typical runner’s marathon. Alex Hutchinson has all the good news and bad news here at Outside Online. 


There’s lots more. Dr. Stacy Sims says creatine is one of the few supplements she recommends for all women. Why? Because “a growing body of research shows it can help increase strength, power, and athletic performance in females, and it’s also good for your brain health and maybe even your mood.” But note: She seems to have a commercial relationship with a creatine company.


A recent 2-yr-long RCT of creatine and bone health of exercising postmenopausal women produced minimal results: The creatine “had no effect on bone mineral density, yet improved some bone geometric properties at the proximal femur.”  More at Medicine & Science in Sports & Exercise.  


On the other hand, a trial that combined strength training and creatine use among senior men and women of average age 68 reached this conclusion: “The use of this supplement [creatine] in addition to RT can double the amount of strength gained from resistance training.”


The “advanced runners” at Reddit are mostly dubious that creatine is helpful, but a few have found it helps their recovery efforts. More at Reddit.


HIT the intervals to increase your response to training

All runners respond differently to different training programs, which is one reason why finding your own best approach is part science, part art, and part trial and error. Years ago, some unfortunate individuals even gained the label “non responders” because they made little or no progress when following a modest fitness program that worked fine for others. 


Since then, we’ve learned that there are few actual non-responders. Rather, different people respond to different training programs. Here researchers wanted to see if a high-intensity program worked better for some.


Subjects began with 10 weeks of typical, moderate aerobic exercise. About 52% responded well, with increases in their vo2 max. But others responded little. 


After the 10 weeks, all subjects continued training for an additional 16 weeks. Half still followed the simple aerobic program, but the other half began doing high-intensity intervals (HIT). All workouts were equal in energy expenditure.


After HIT training, the response rate jumped to 87%. Conclusion: Simply “maintaining moderate endurance training intensities might not be the best choice to optimize training gains.” Hard intervals can give a significant boost. As always, you have to be careful not to overdo the intervals, as they can increase risk of injury and overtraining. But they can also make you fitter. More at Sports Medicine Open with free full text.


6 nutrition mistakes you need to avoid     

If you’re a running nutritionist, you probably see everyday mistakes that are repeated by many runners. For example, you’ll note runners who don’t fuel for their runs, maybe fearful of fullness or stomach distress. Of course, the result is a subpar workout that doesn’t advance one’s fitness as much as it might.


That’s one mistake that Meghann Featherstone observes frequently among her clients. Here she lists 5 more. These are commonplace, which doesn’t make them un-important. Quite the opposite. You can make big gains if you successfully tackle a couple of these.


The mistake I hear the most about--and, hate to admit it, make too often in my own life-- is this one: “Saving calories for the end of the day.” It’s healthier to consume them earlier, so you can burn them off with movement and exercise. At the end of the day, you’re just skyrocketing your glucose-insulin response while eating and sitting (in front of Netflix), and then sleeping. Better to reverse the calories-movement order. Eat first, then move. More at Featherstone Nutrition.


Rx for injuries: Rest is not enough. You need PT as well  

Here a top American running physician, Adam Tenforde, and a German colleague explain how they go about their medical practice with runners, primarily the treatment of injuries. They note that many runners won’t consult with physicians for fear of being told to stop their running. 


This is a necessary step for bone stress injuries (stop running), but not necessarily for Achilles tendinitis. In fact, evidence from management of Achilles tendon disorders “suggests pain below 5 on a scale of 0 to 10 can be acceptable during running for long-term recovery.” Just be certain to also follow “a structured tendon loading program to restore tendon function.”


For most injuries, rest alone is not the best approach. Rather, “physical therapy should be standard for any running-related injury, as relative rest does not reliably treat the underlying impairments that contribute to risk of the injury.”


Mental health of runners is important to address, as many runners practice the sport “to deal with life stressors.” Finally, cross training “can provide alternative forms of physical activity to maintain cardiovascular fitness and enjoyment of physical activity.” More at German J of Sports Medicine with free full text in English.


Doubts about “superfood powders.” But multivitamins improve memory

Oops. About half of my favorite running podcasts are sponsored by Athletic Greens, a powdery supplement that claims it “promotes gut health, supports immunity, boosts energy, and helps recovery.” There are several other “superfood powders” that appear to be quite similar. But when the NY Times asked a handful of nutritionists what they thought of the powders, the reviews were cynical.


“This is like throwing the kitchen sink into a powder,” said one nutrition expert. Another responded: “Why not just eat spinach?” Representatives from the companies admitted they had “no rigorous, independent studies” to support their marketing pitches.  More at NY Times.


Many supplements face a similar fate when evaluated in population trials. But wait, some do succeed. One recent supplement paper actually reached a positive conclusion, and made big headlines in the act. A multiyear study “of 3,562 older adults” showed that use of a popular multivitamin pill (Centrum Silver) vs a placebo pill resulted in significantly better scores on a memory test after 3 years. 


Conclusion: “Multivitamin supplementation holds promise as a safe and accessible approach towards maintaining cognitive health in older age.” More at The American J of Clinical Nutrition.


Minimalist shoes can reduce knee-joint forces

In this systematic review and meta analysis, researchers sought to answer the question: Can a particular type of shoes, or the use of insoles, reduce knee joint forces (and, presumably, pain and injuries) in walkers and runners. They found 33 relevant studies that investigated their key question with 578 subjects. 


Result: Minimalist shoes reduced knee joint forces by 9.5%--a result that could have “clinical relevance” given the number of strides that runners take on a typical run … or across  years of running. Medial support insoles “may not alter patellofemoral joint loads during walking or running,” or have any effect on knee pain. Similarly the effect of rocker-type shoes is “very uncertain during walking and running.”


Conclusion: “Clinicians aiming to reduce patellofemoral joint loads during running in people with patellofemoral pain or osteoarthritis may consider minimalist footwear.” More at Brit J of Sports Medicine.


Do hormonal contraceptives decrease muscle-bone injuries?

It’s believed that many young women athletes use combined hormonal contraceptives (CHC) in part as a hedge against musculoskeletal injuries. But is there any evidence that this is an effective practice? Answer: Very little, if any.


Researchers performed a systematic review with data from 5 million female athletes. They looked for 30 different kinds of injuries, about 75% of them relating to bone issues. Outcome: There is “a paucity of high certainly evidence.” Therefore, “It is premature and inappropriate to advocate, or prescribe CHC for these purposes.” More at British J of Sports Medicine.


Another female-centric review showed that females adapt well to heat training, much as males do. A systematic review and meta-analysis of female-only studies showed that 2 weeks of consistent heat exposure produces “physiological adaptations beneficial to thermoregulation and performance test outcomes in the heat in females.”


How much heat training do you need? Here’s a precise little recipe. It takes: “durations of 451–900 min and/or 8–14 days of heat exposure.” More at Sports Medicine with free full text.


This would probably make good training for the 10 or so women entered in the Lululemon Further Ultramarathon scheduled for next year’s International Women’s Day--March 8, 2024. It’s a six-day ultra--mimicking a historic if rarely-run distance--and will be supported by a crack scientific team from the Canadian Sports Institute Pacific.


This is a great idea modeled somewhat on Eliud Kipchoge’s two highly-publicized attempts to break 2 hours in the marathon. The winning time (actually distance in this case) isn’t as compelling as Kipchoge’s 2-hour-goal, but the extreme challenge along with a heavy dose of endurance research should prove enticing.


Lululemon has the wherewithal to promote the event heavily, women’s endurance is a hot topic in the sports, science, and media worlds, and star athlete Camille Herron has enough charisma to handle the spotlight. I’m already looking forward to this one. More at Lululemon.


SHORT STUFF you don’t want to miss

>>> A pound in time: What is your best race-weight, and does it really matter?

>>> Motivational tip: Beginning your workout with a hard effort and ending it slower and easier might improve enjoyment and motivation.

>>> Sex and hyponatremia: Female Ironman triathletes lose less weight in competition than males, and are more likely than males to develop hyponatremia (free full text)



GREAT QUOTES make great training partners

“Discipline is choosing between what you want now and what you want most.”

--Abraham Lincoln