The popular story of how low-carb diets work goes something like this: Reducing your carbohydrate...
Let me introduce myself. My name is Mark Sisson. I’m 63 years young. I live and work in Malibu, California. In a past life I was a professional marathoner and triathlete. Now my life goal is to help 100 million people get healthy. I started this blog in 2006 to empower people to take full responsibility for their own health and enjoyment of life by investigating, discussing, and critically rethinking everything we’ve assumed to be true about health and wellness...Tell Me More
If you’ve been reading this blog for any amount of time, you know I’m always interested in exploring those time-tested bits of advice, those old wives’ tales, that folk wisdom handed down generation over generation because they’re often right, or at least contain a kernel of truth. And if a piece of conventional folk wisdom turns out to be wrong or misguided, understanding why it endured for so many years is a fun exercise and usually reveals other messages and truths. Today, I’m looking at the importance (or lack thereof) of breakfast. For years, you’ve heard how important breakfast is. Your grandma says it. Your doctor probably scolds you if you’re not eating it. We all grow up having this “fact”—breakfast is the most important meal of the day—drilled into our subconsciouses. Even the people who just don’t feel hungry in the morning feel guilty about it and compelled to stuff something into their craws.
Nutritional studies are often the best we’ve got. Without them, we’d be plucking anecdotes from a swirling vortex of hearsay, old wives’ tales, and prejudices. Some actionable information would definitely emerge, but we wouldn’t have the broader vision and clarity of thinking offered by the scientific method. Most of them are deeply flawed, though. And to know which ones are worth incorporating into your vision of reality and which only obfuscate and further muddy the waters, you have to know what to watch out for.
Today, I’m going to discuss many of the reasons you shouldn’t trust the latest nutritional study without looking past the headlines.
For today’s edition of Dear Mark, I’m answering three reader questions. First, if things are going well on a relatively low-calorie intake, should you just keep on keepin’ on or should you increase food intake to “get ahead” of your needs? Next, what’s the deal with a study showing a high-carb diet is better for testosterone levels than a high-protein one? What does this mean for your Primal way of eating? And finally, can an improvement in heart rate variability after a carb refeed indicate a greater need for carbs?
For today’s edition of Dear Mark, I’m answering three reader questions. First, do anaerobic workouts—sprints, lifting, etc.—interfere with your ability to become a fat-burning, aerobic beast, or can you integrate them? Next, in last week’s post I talked a lot about glycogen depletion in the context of the “sleep-low” carb partitioning. How can we actually achieve this without doing the intense intervals the elite triathletes were doing in the study? And finally, does carb-fasting after strength training also work?
Thought experiment time. Say you train hard, hard enough to deplete a signifiant amount of glycogen. Your muscles are empty, sensitive to the effects of insulin, and screaming for a couple potatoes to refill glycogen. What do you do?
In most circles, the answer is to eat those potatoes and refill those glycogen stores. And why not? The post-workout period is a special window of opportunity for eating a bunch of carbs and having them go to the right places with minimal insulin required. They won’t contribute to fat storage. They’ll go straight to your muscles. Restocking glycogen sets your muscles up to repeat the hard work and keep up with your training. It makes sense.
What if you didn’t eat the potatoes after a hard workout? What if you abstained from carbs entirely after a glycogen-depleting workout? What if you just went to bed without any (carbs in your) supper? What if you were an elite athlete and skipped the carbs?
This isn’t a Homeric epic. There are no oracles laying out our destiny and predicting our inevitable demise. But even if we can’t know the precise date of our death, we can use certain biomarkers, measurements, and characteristics to make predictions—with a reasonable amount of accuracy—about a person’s propensity to kick the bucket.
As is the case with any observational data, these predictors may not be malleable. And if they are malleable, actively changing them won’t necessarily confer the longevity they’re associated with. Getting plastic surgery to appear younger probably won’t make you live any longer. But they do tell a story. They suggest the qualities, activities, behaviors, and exercise patterns that may, if maintained, lead to a better, longer life. At the very worst, walking a bit more briskly and gaining some lean muscle won’t hurt you, and it will very likely help you.