Meet Mark

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...

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Category: Weight Loss

Dear Mark: Do I Need to Eat More, Testosterone Levels, HRV and Carbs

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?

Let’s go:

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Dear Mark: Staying Aerobic, Glycogen Depletion, and Sleep-Low for Strength Training?

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?

Let’s go:

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Should You Sleep-Low to Boost Performance?

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?

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10 Interesting Predictors of Longevity

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.

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Can Exposure to Non-Primal Foods Actually Help?

Are we shortchanging ourselves by complete elimination of potentially allergenic or sensitizing foods like wheat, peanuts, or dairy? Do we become even more sensitive to “bad” foods by avoiding them entirely? This question stems from two things I recently encountered. The first was a recent rewatcing of The Princess Bride. The second was the recent peanut allergy study.

If you haven’t watched The Princess Bride yet, go do it (the book is also good) because a small spoiler is coming. The hero Wesley spikes the wine he and the villain Vizzini are sharing with iocane powder, a fictitious ultra-lethal poison that kills instantly. But because Wesley has spent the last several years ingesting incrementally-larger doses of the poison, he has complete resistance to its effects. Both men drink. Only Vizzini dies. What else can this apply to? I wondered.

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Top 14 Ways to Increase Your Metabolism

On a literal level, your metabolic rate describes how much energy you expend to conduct daily physiological functions. This has many practical ramifications, however, because your metabolic rate also influences how you feel, how many calories you burn, how many calories you can eat without gaining weight, your libido, your fertility, your cold tolerance, how much subjective energy you have, how you recover from injuries and stress, how specific foods affect you, and how you perform in the gym. In short, it’s usually a good thing to have a higher metabolic rate.

Here are a few ways to increase your metabolism in a healthy, productive manner.

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