Dear Mark: Tweaking Sprints for a Stressful Life; Carrie’s Primal Transition

SprintFor today’s edition of Dear Mark, I answer one question and Carrie answers another. First up is one from Diane, a (full-time) working mother who’s noticed something interesting about her variable response to sprinting: when she’s relaxed and low-stress or on vacation, sprints lean her out; when she’s working and inundated with stress and responsibilities and concerns, sprints make her retain or even gain body fat. Since she realizes the power of sprinting and doesn’t want to give it up completely, Diane wants a few tips for hacking sprints on a high-stress lifestyle. Next, Carrie gives a quick overview of her transition into the Primal lifestyle and breaks down what Primal living looks like for her these days.

Let’s get into it:

Hi Mark,

I have a question about sprinting. I have been living the primal lifestyle for over 3 years now, have the food and exercise dialed, however encounter daily stresses of raising young children and full time corporate work. I incorporate sprinting once a week, however seem to retain or GAIN fat on my stomach after sprinting. When I am on vacation and relaxed, the sprints work like they are meant to and shed fat. Should I not be sprinting while leading a stressful life, as I appear to be adding cortisol to more cortisol which is leading to belly fat? I would hate to give up my sprinting as I love the other benefits they bring such as increased power and ability to chase after my children. I currently run 8 x 30 second sprints with 90 seconds recovery in between, on a track or up a hill. Is there a way to tweak my sprints so that they are not so stressful to my body.

Thanks so much,


Okay, first off: great job being cognizant of how sprints affect your body differently depending on the baseline level of stress in your life. That’s huge.

It can be disconcerting to see weight come on or stay put despite best efforts. It’s not fun to be “sensitive” to stress-related weight gain. But I actually think it’s a blessing in disguise.

Most people drift through life gaining weight here, losing weight there, eating this, exercising that way without ever putting two and two together. They’re rarely ever able to optimize their eating, exercising, and other lifestyle factors based on any real world, personable evidence. They do what someone else says – maybe me, maybe some other “expert” – and hope for the best.

Your sensitivity and your intuition allow you to spot incongruities and intolerances. You have the ability to tailor your lifestyle to your body and its requirements. You know what works for you and what doesn’t work because you notice what happens when you change a routine.

That’s rare and it’s awesome. Cherish it. Use it.

Now, some thoughts on sprinting and a stressful life.

Eight 30-second sprints with just 90 seconds of rest in between are kind of a heavy load for anyone, let alone a heavily-stressed working mother. Many of the most effective sprinting studies employ four – not eight – 30-second sprints with three to four minutes – not 90 seconds – of rest in between. And the subjects are often young college students for whom a stressful day means having to wake up before ten o’clock. Oh how I wish my life were like that again.

Traditional sprinting is far more demanding than the sprint cycling often used in exercise science. Few studies even use straight on sprinting unless the subjects are experienced athletes due to the degree of difficulty required. Sprint cycling also doesn’t really engage the upper body at all, whereas sprinting is a total body endeavor.

All that said: I’m confident you can still sprint and accrue benefits, even undergoing external stress, but you’ll have to change things up and make a few tweaks.

30 second sprints require more rest. Period. Some people may be able to handle them with truncated rest, and a carefree relaxed version of you appears to be one of those people, but a stressed-out time crunched version of you is not. Extend your rest periods to three or even four minutes instead of a minute and a half. If that’s “too easy,” you can always slowly reduce your rest as long as you’re still getting beneficial effects.

Don’t do eight of them. That’s way too many for you. They’re no joke and you don’t need to do eight of them. Heck, in one study, men and women did “just” three 30 second all-out sprint intervals on the stationary bike with 20 minutes of rest in between each sprint and they still got results. I’d say start with four and work up or down based on how you respond.

Try shorter sprints. Try 20 seconds instead of 30. Even shorter sprints work, too. In fact, a program consisting of three sets of 5 4-second treadmill sprints with 20 seconds of rest in between each sprint, done three times per week for four weeks up-regulated molecular signaling associated with mitochondrial biogenesis. More mitochondria mean greater energy production and consumption, improved substrate utilization, and overall better metabolic health. Don’t be afraid to run a series of 4-6 second sprints with minimal rest. It’ll feel “easy” compared to your normal routine but it’s still working.

If you’re going to run hills, definitely make the sprints shorter. 30 seconds of sprinting uphill is far more stressful than 30 seconds of sprinting on flat ground. Whenever I run hills, I knock my normal sprint time down. Try 15, maybe 20 seconds instead of 30. Remember, the benefits (and stresses) of sprinting depend on effort expended, not the duration.

Find the point where you start to slow down and stop there. We all have that point. Very few people on the planet can maintain top speed for 30 seconds. You probably aren’t one of them (I’m certainly not). And it’s not that continuing to run after you’ve lost your top gear isn’t useful. It is. It’s just really, really hard on the body. Since your ability to recover from stress is slightly impaired, you’ll likely do better with true sprints that stop once you start to slow down. Besides, as you get stronger, fitter, and faster (from actually recovering from the sprints now!), you’ll find that you can run a little longer at your top speed each time.

Whatever tweak you try, use your well-documented powers of observation and interpretation to determine its efficacy. Good luck!

Hi Mark,

Would love to hear more about Carrie’s background and her transition into the primal lifestyle. No offense, but as a woman it’s hard to believe doing the exact same thing a man does produces the same result. Would also be great to hear what she is doing on a daily basis.

Best to you and yours,


I stopped eating grains over a decade ago, even before we went Primal. My nutritionist at the time said I was allergic to them. I was always bloated with a pouchy stomach (despite being overall quite lean and fit) until I stopped grains and legumes completely. So when we did go full Primal, it wasn’t a big shock. The logic made sense. I was ready. I’d already been following maybe the most important aspect of Primal for a couple years so the rest just fell into place and felt completely natural.

I did not eat meat for 30 years. In the last 10 years I added in fish and just last year all other meats. I still get the majority of my protein from Primal Fuel and fish because I feel better that way. But I will say that including other meat has made me feel better, have more energy, and maintain greater muscle mass while staying leaner than ever before. I guess it doesn’t take a lot to make a difference.

And I’m not 80/20. No way, no how. The 80/20 rule definitely doesn’t work for me. When I tried it, it inadvertently became 60/40, so now I shoot for 100% and end up being 90/10. That’s important. You have to be honest with yourself and learn about your weaknesses. That’s mine: give me a little breathing room and I’ll take way too much. If I aim for perfection, I get to where I need to be. Your weakness may be something else, but you have to acknowledge and own up to it to get better.

I’ve always loved to work out and I always will. Mark and I met at the gym. Fitness was kind of our first mutual passion. It’s where we clicked. Nowadays, I actually spend way more time working out than Mark does, believe it or not! And living with Mark inspires me. I like to think I do the same for him. We keep each other on our toes.

I work out in the gym with a trainer and lift weights 3 days a week for an hour, I sprint 2 days a week (best ever exercise for my glutes and thighs), I do yoga 2-4 days a week, and I hike as well. And yes, that means 2 workouts a day some days. Didn’t I say I loved to exercise?

Vanity does come into play, no doubt about that. But exercise is also a way for me to lose myself in the moment and tap into the flow state that I think we all need to hit from time to time. Exercise is active meditation for me. If a workout is really intense, I can only focus on it and everything else melts away. And yes, even yoga is intense, just in a different way than lifting heavy weights. It takes perhaps more concentration than other forms of exercise.

Sleep is key to my feeling good. I sleep 9 hours a night and if I didn’t I doubt I’d recover from all that I do. Sleep has to come first. Most people think of sleep as an end to the day. I think of it as the beginning of my day.

After waking up, I always start with meditation, writing in a gratitude journal and reading something spiritual that inspires me. And I do this every day because with it I am in the flow all day long and life is ease and grace – even when it’s not. Even when I’m working hard and the task is difficult, my morning rituals prepare me for them. It lets me accept the task and commit to it without giving it a value like “this is unpleasant” that throws me off or makes me want to procrastinate. Then I may check emails and I’m off to workout and get on with the rest of the day.

This summer I will be doing a webinar and I will go into greater detail about how I do Primal! Then the book is coming, which will really clear things up. Thanks for writing in!

Primal Kitchen Hollandaise

About the Author

Mark Sisson is the founder of Mark’s Daily Apple, godfather to the Primal food and lifestyle movement, and the New York Times bestselling author of The Keto Reset Diet. His latest book is Keto for Life, where he discusses how he combines the keto diet with a Primal lifestyle for optimal health and longevity. Mark is the author of numerous other books as well, including The Primal Blueprint, which was credited with turbocharging the growth of the primal/paleo movement back in 2009. After spending three decades researching and educating folks on why food is the key component to achieving and maintaining optimal wellness, Mark launched Primal Kitchen, a real-food company that creates Primal/paleo, keto, and Whole30-friendly kitchen staples.

If you'd like to add an avatar to all of your comments click here!