Dear Mark: How Many Sprints Per Week, How to Play and Train with Babies, and the Best Nighttime Snack

Baby finalFor today’s Dear Mark, I’m answering three questions. First, how often can a person sprint safely and effectively? There are many factors to consider when determining the amount of sprinting a person can handle each week, like stress levels, sleep, and other training, so it’s tough to give a specific number. Next, what are new parents supposed to do for physical play and exercise? Aren’t babies fragile, helpless things? No. As you’ll see, it’s possible and even desirable to expose your young children to intense (but fun) play and exercise and introduce elements of cautious risk-taking into your time with them. Finally, what’s the best nighttime snack alternative to nuts and dried fruit?

Let’s go:


I currently sprint every 4 or 5 days (bike sprints, total time on bike 22-25 min, with 6-8 30 sec sprints). I also strength train twice a week. I know we only need to sprint every 7 to 10 days to maintain the health benefits, but I love sprinting. As a former chronic cardio Type A, I fear I’m going to increase my sprinting frequency until I’m doing it everyday which would clearly not be good for me. What’s the most frequent I can do them without it becoming detrimental to my health?

If you want to sprint more often, it usually comes out of the rest of your training.

Of course, many of the pro-sprinting/HIIT studies use multiple sessions per week and get great results. What gives? In order to exclude any confounding variables, they generally forbid participants from engaging in other exercises. So in a HIIT study, you’ll just do HIIT and nothing else on the side. You won’t lift weights, or go on hikes, or any other formal exercise. You’ll be focusing on HIIT and HIIT alone so as to isolate the effects of the experimental condition. The absence of other training coupled with the total dedication to the program allows adequate recovery.

If you weren’t doing anything else, I’d say you could get away with three or four sprinting or HIIT days a week. I think, though, that optimal fitness is achieved through a more well-rounded approach that includes lifting heavy things, play, lots of slow moving, and yes, sprinting (or HIIT). All those activities require recovery time. We can and do learn from fitness studies, but in reality we can’t just take what studies do wholesale. We would fail, or be required to sleep twelve hours a day, or eat 4000 calories, or go back to college and shirk our responsibilities.

You must also consider the subjects of these studies, which usually use students because they have a ton of free time and often need the money.  More free time means more recovery time and being a student means less psychological stress (except for perhaps during finals), which can also impact your workout recovery. Worrying about getting laid or what to wear to the frat party on Friday is less stressful than worrying about bills, dealing with family issues, or having to commute an hour each way every day.

If I had to give you a figure—which I can’t really do given the paucity of information I have—I’d say you can probably get away with an extra sprint session per week given that you’re only lifting twice a week. However, if you’re truly going all out 6-8 times for 30 seconds on a bike each session, that’s like doing two Wingate tests, which researchers use to determine peak anaerobic power and capacity. People who’ve done the test (4 30-second all out bike sprints) often rate it as the hardest thing they’ve ever done. Puke buckets are a standard feature of the Wingate test. So ask yourself if you’re really going hard enough. If not, maybe drop it down to 4 30-second sprints and really go for it. Then see if you’re still interested in more sprinting.

Most people who want to sprint all the time aren’t really sprinting.

Although I walk and get sun everyday, I’m struggling to figure out the ‘play’ aspect of the 21 day challenge. I have a 7 month old baby girl that is truly a blessing, but anything I do…She needs to be able to come along! Please, any ideas? Thanks!


Seconded! I have an 11 month old and I’m wishing so badly that I could climb trees and sprint (both things I used to thoroughly enjoy) while holding him.

There are tons of things you can do with your little ones.

You can still climb trees. Look, maybe your pediatrician wouldn’t recommend this. Maybe your mother-in-law (or wife or husband) will flip out on you. But as long as you’re careful, you can climb trees while holding your kid. Maybe not to the top, or even halfway, but you can certainly monkey around in trees while staying close to the ground. Get the kid used to being in a tree. Let the kids climb the tree themselves. Show them how to hold on to large branches and hang from smaller ones. Leave the kid at the bottom of the tree and see how quickly you can reach the top and get back down (unless dingos abound, no one’s going to steal your baby) before the cries start. Do this often enough and your kid will realize that being away from you for a minute or two isn’t the worst thing in the world and everything will actually be okay (you might learn something similar).

Sprinting? Yeah, you can sprint. One of my employees did extensive hill sprints while holding his sub-1 year old daughter on a regular basis. Clutch the kid like a football, hug them to your chest, keep a hand on their head to prevent flailing, and just go for it. Hills seem to work better, since you’re falling a shorter distance and there’s less of a jarring impact.

Once the kid can stay on your back and hold onto your shoulders/neck, take them for a ride. Crawl around with them on your back. Spin around 18o degrees while crawling, moving ever faster as they get better at holding on. Do some hops from a squat position, a la Darryl Edwards’ bunny hops. Kids love this, it builds their strength and confidence, and it’s great for your fitness.

Kids are great weights. They’re like medicine balls that get heavier as you get stronger. Swing them like a kettlebell (cradle the head/protect the neck/watch the splaying legs). Toss them. Squat down and push press them up into the air, catching them in a full squat. Single arm press them overhead. Do Turkish get-ups.

Roughhouse. Roughhousing is a lost art. Chances are your kids’ friends won’t be allowed to do it, so you may have to toss your kid around a bit to teach them. Do so lovingly and playfully. Here’s a nice example of daddy-daughter roughhousing from Rafe Kelley.

Wear your kid. You’d be surprised at how much you can do with a kid attached to your chest (or back).

What else can you think of? Be creative.

I am a big night snacker. Dried fruit and nuts have been my go too but I don’t want to over do it. Trying to find something to replace and then eventually get over the snacking.

Herbal tea jello.

Brew non-caffeinated tea of your choice. Maybe a chamomile or ginger tea.

Stir in powdered gelatin until it dissolves in the hot tea.

Add a touch of sweetener, like raw honey or stevia.

Refrigerate until solidified.

The gelatin (specifically the glycine content) will improve the quality of your sleep (and make you less groggy after sleep deprivation). You’ll get a fun treat before bed. Win-win. This also works with caffeinated liquid, too—coffee, green/black tea—if you want something earlier in the day.

TAGS:  dear mark

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.

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41 thoughts on “Dear Mark: How Many Sprints Per Week, How to Play and Train with Babies, and the Best Nighttime Snack”

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  1. I needed this reminder that I need to start sprinting more often because I rarely ever sprint anymore.

  2. I only sprint once a week, about 75 to 80 yards up a steep driveway, then a slow walk back down to my starting point, 5-6 times. But then I’m 68.

  3. I surf about 1.5 to 2 hours a day. Sometimes more. Rarely less. I supplement with about two spinner bike sessions per week (15 to 18 minutes tops with three sprints mixed in) and about two to three really intense saw planking sessions per week ( 7-8 min. downward, 3-4 min per side and then another 2-3 min downward to finish off). Usually I do these after surfing. If it’s flat or blown out from storms, that’s all I’ll be doing (either one saw plank session or one spinner bike, never both) I also don’t plank before surfing because it pre-exhausts my core and I feel unstable on the waves.

    I should point out that after 30 years, surfing is not that difficult, but it is still exercise, especially when it’s pumping.

    Lessons for me. Keep the sprinting as a supplement. On long flat spells I may do them every other day. When it’s pumping it can go as low as one session per week. Listen to your body. When in doubt, don’t max out. Don’t do a core/sprint routine before your regular routine. Do them after. You also don’t have to do as much (three sprint is plenty) because you’ve already worked your core/legs. Plus you’re already warmed up, so less chance of injury.

    BTW I’ll be 50 years old in June. So not a young college student

  4. I get hungry in the evening maybe because we usually eat dinner fairly early around 5:30. Sorry, Mark, the herbal gelatin doesn’t get it for me! I make an avocado pudding but I’m tired of it and need some variety. Would appreciate more suggestions. Give us some variety; sometimes you want crispy/salty, other times something smooth like ice cream. Want to combine protein + fat and a few carbs. Any other suggestions would be much appreciated!

    1. Crunchy salty: dry-roasted chickpeas? They come in lots of flavors.
      Smooth & creamy: nut-butter & coconut oil
      In food processer, blend nuts to nut-butter, add roughly equal amount of coconut oil, season with dried fruit and spices. I like almond-walnut w/ raisins and cinnamon or cashew w/dates and curry powder. Spoon into small glass containers and keep in the fridge. You can add protein powder as well, flavored or unflavored. These are obviously very caloric, but scraping the cool deliciousness out of small containers is truly satisfying…I would chose this over ice cream any day.

    2. one of my favorites if I’m craving ice cream….. 1/2 frozen banana, couple of handfuls of frozen blueberries…… whizz it in a blender or food processor…. instant soft style ice cream…!!!

    3. Ants on a log: celery filled with cream cheese or almond butter and dotted with dried fruit of your choice. Apple slices with peanut butter, and maybe dusted with cocoa and cinnamon. Shaved salmon and cream cheese or butter on rice crackers. Fresh fruit and nuts (salty, sweet, or plain).

    4. If you get hungry, then what you’re looking for isn’t a snack, it’s a mini-meal. You could try to change your meals schedule to eat dinner later, or eat some of the same thing you ate for dinner. I was in the habit of an early dinner, and craved something to eat again at 9-10 PM. So now I have a snack or a cup of tea or take a walk when I get home, then eat dinner later.

      Or instead of thinking that food after dinner has to be a sweet or a treat, just think of it as food or another meal and that change in perception will open up all the possibilities.

      1. Hard cooked eggs are a perfect late night snack. The process of taking two hard cooked eggs, spliting them, and making a deviled creation is very satisfying. Mixing the yolks with hot sauce is my typical go to. Chopped pickles, capers, salmon, or whatever you have in the fridge. Last night I dusted them with the crumbs left in a bag of fried pork rinds. Today, pork rinds are at the top of my shopping list. That was awesome. Make a mini-meal a process and take your time. Otherwise you are just snacking back to convenience food habits. Are you hungry or just bored? Create something delicious and nutrient dense with eggs. Then you can skip breakfast knowing that you had it last night.

    5. Whatever happened to yogurt with berries, macadamias and/or a dollop of honey?

  5. I used this sprint routine for years (“diluted tabata” I called it) , once a week usually on Wednesdays:

    2 sets of 8 sprints runs, separated by 2 minutes
    One run or interval is approx 90m run with with approx 12m walk.
    When I started doing them I had to start doing 3 sets of 4, with the 2 mins rest, and the total time was like 16 or 18 minutes.

    But now … much better, I did the 2 sets of 8 in 11:30 mins last Wednesday
    And I have my “record” of 9:40 (skipping the 2 min rest)

    Recently started doing sets of 200m, with one minute rest. MUCH HARDER (most of the times I do 5, 6 in good days, record of 7)
    Not bad for a 64 year old

  6. Re: nighttime “snack” … good suggestion by Mark. What I do is drink a whey protein drink at night, lots of good benefits as Mark has pointed out a few times in his articles.

  7. I’m not sure which college kids you’re taking about Mark. I had to worry about paying bills, deal with massive family issues, and commute an hour back and forth each day. I also worked. Where are these college kids you speak of who aren’t stressed again? We haven’t gotten a free ride or close to it since the 70s. A lot of the young adults I know who are going through it now work two jobs, pay rent, and at least try to get good grades all year around, not just for finals. Sounds pretty stressful to me.

    1. I’m amazed by the college kids who do it all! Im inspired by the hard work & dedication I’ve seen.

      I live in a college town, though, and I have also seen exactly the students Mark was talking about.

  8. Thanks for the suggestions. I wear my 11 month old (almost a year old now) a lot every day, but can’t wear him on my back anymore because he discovered the joy of hair pulling. I try to wear my hair in a bun to prevent that and he grabs it by the roots. I’ll have to try climbing with him in the carrier and the sprint suggestions as well. Gonna be hard to sprint while holding 25+ lbs like a football (I’m still not able to do a pushup yet), but I’ll give it a shot.

    1. Lie on you back and push your child up. Do as many reps and you can. Do this every day and by the time your 11-month-old is is preschool you will be doing pushups like a champ.

    2. I had the same problem with my daughter pulling my hair even when up in a tight bun. What I found helped was wearing a cloth head band that covered up the area where your hair meets the nap of your neck, and wearing a chew bead necklace (the kind made out of silicone) to distract her.

      1. I’ve tried wearing a hat, which he pulled off almost immediately. Hm, chew bead necklace… I’ll have to see where I can get one of those. Thanks for the advice. 🙂

  9. Curious, Mark, where would you rank a game of basketball in the spectrum of sprinting/lifting/play? I feel like in encompassing all three, but at age 35 and playing once a week, I want to make sure I’m not overdoing it especially if I’m also doing bodyweight lifting (pushups + pull-ups+squats) 3 days a week.

    1. If you like basketball, you should play it. Three days a week of body weight plus one game of basketball is hardly overdoing it. That sounds like a moderate maintenance routine to me. Keep in mind that Mark’s chronic cardio advice is coming from a guy who had a career as a triathlete/endurance athlete. Most people are not in any danger of over exercising. And if you play basketball more often it will get easier on your body as you build up conditioning, thus actually reducing the chances of overdoing it.

      1. Great advice, thanks Clay. I have played weekly basketball most of my life since I was a kid. As I get a bit older, though, I find it often takes a couple days to completely recover. We do go pretty hard in the leagues/weekend games, often playing for anywhere from 1 to 3 hours.

  10. Love the herbal tea gelatin idea…I did it with very tart lemonade sweetened with stevia and loved it! I sneak gelatin and collagen in wherever I can. Has done wonders for my skin and nails!

  11. ‘Most people who want to sprint all the time aren’t really sprinting.’

    Exactly. I dread my once every week or two 6 all out sprints. Glad when they’re finished.

  12. I slacked off on the sprints once a week for a while, and I started to notice a drop in all round fitness and energy (not to mention an increasing waistline) – they really work, but from my own experimentation, once a week is enough, combined with other training and active lifestyle.

    The sprinting definitely raised my energy levels for my heavy lifting workouts, and vis-versa.

  13. I know it’s not fully primal, but personally I love to indulge in super aged raw milk cheddar cheese as an evening snack. It’s a brick of fat and proteins with some carbs and clearly kills a craving. Again, you might be avoiding dairy so this would be a no-go. I am also blessed to come from an area where we have good quality milk and where raw milk chesses (mostly cheddar) have gotten real popular in the last decade or so.Knew a place where they used to sell 8 years old *drool*

  14. Maybe this is obvious, but I sprint with the toddler in the stroller. We’re in NYC, so lots of walking for him, but sometimes need to stroll him. And then I always try to do some of the blocks as sprints – and he loves it so much he usually ‘reminds’ me that it’s a good time to sprint.

  15. Agreed on the college kid thing. I and most of my friends work multiple jobs and deal with alot of outside family or community issues, volunteer, and try to keep our grades up. The investment will pay off, so I am not complaining, but I’ve never seen school as a “stress free” time. The most “stress free” I’ve ever been was a year inbetween grad and undergrad when working a normal 8-5 job. It was pure bliss.

    I know there are some kids like that – but not that many at most schools.

  16. When my niece was maybe a year old, I would hold her and sprint, as well as do things like jump squats. She absolutely loved it, and as she grew older she started to love doing those things herself. I wasn’t even think?gnof it as exercise for myself, I just liked playing with her and seeing her laugh and smile. So, yes, not only can
    you play with your baby like that, but you absolutely should because it will do phenomenal things for your relationship with your child, and your child’s relationship with movement.

  17. I run 3, 1/4 mile runs (walk 1/4 mile in between each) at lunch once a week; on the weekend I run 10-12, 100 m dashes at track (walk 100 m in-between, then run the home stadium steps. I’m 60.

  18. RE exercise with a little one, I suggest dance — it’s free, it’s fun, it’s a great stress-reliever, and it’s an activity that parent and child can do together, and both reap terrific benefits. Throw on some fun music, put the baby in your arms, on your hip, whatever – and just boogie together. Gently lifting baby in the air and away from your own core is an incredible challenge on your stabilizing muscles, and baby will wonder at the world moving by in new ways. We danced as part of our evolution – and indigenous cultures still enjoy dance as a part of every day life for people of all ages. Enjoy!

  19. Mark,
    Thanks for the answer on sprinting frequency. My ever changing fitness routine has evolved to where I’m now sprinting just once every 9 days. I found that every 5 days was too frequent as it really knocks me out.

    I use a Life Fitness stationary bike that has resistance from 1 (easiest) to 20 (hardest). I start out at level 12 for 2 minutes (avg RPM ~60-75); then increase to level 14 for 30 second sprint (avg RPM ~104-112, METs spike to ~18.3 at beginning of sprint, RPM declines from ~112 to 104 over the course of 30 seconds, I do everything to never let RPM dip below 100); then back to level 12 for 2:30 recovery cycle with RPM ~60-75; then sprint 30 seconds again, etc. for usually 6 total sprints (sometimes 8 if I’m feeling masochistic). I’m pretty tired for the rest of the day.

  20. Thanks to all for the great snack ideas! My “go-to” would be some dark chocolate & maybe some nuts. Trouble is, I don’t stick to one ounce of chocolate and a “few” nuts! I do add chocolate whey powder to half a frozen banana though, sometimes a few berries in it and that’s great but not much fat.

  21. Mmm never thought of tea jello. I like to make lemon jello with gelatin and throw in a handful of blueberries. Great treat, especially when it’s hot out!

  22. I’ve used this routine for over a year. I have obviously added more difficulty by including more advanced progressions, but I pretty much stuck to the same HIIT format:


  23. 1 km run.
    Warm up
    1m rest between sets and 2m rest between supersets
    Four sets of 10 kettle-bell squat thrusters + 12 kipping pullups
    Four sets of 15 jumping lunges + 15 clap pushups
    5-6 80-90m sprints (reaching full sprint max only on the 5th and 6th sets)

    What are your thoughts on sprinting after working out? Should I dedicate separate days for sprints or is it okay to incorporate them as above?

  24. About those late night snacks. Not such a a good idea. After years of “a little something” (usually cheese and or chocolate) before bed, I developed nasty gastric reflux. Three years on Prilosec lead to osteoporosis (not enough acid to properly digest minerals despite my copious consumption of dairy) and finally surgery. It wasn’t until after the surgery when the symptoms started coming back (WTF???) that I finally bit the bullet and stopped snacking before bed. It was HARD. There was something of an addictive component to the habit. I thought I would never be able to get to sleep. But raging acid up my esophagus is a powerful motivator. I suspect now that the late snacking for all those years was the primary cause of my GERD.

    I started a plan of no eating with 3 hours of bedtime and a full 12 hour fast from dinner to breakfast.

    The good news? I dropped 20 pounds in three months without even trying. (I know!) And I have had NO reflux symptoms at all. I can eat anything on the anti-reflux diet list, as long as I don’t lie down after.

    The problem took years to develop. But man, do I wish I had known then what I know now.

  25. A great way to sprint consistently is Dragon boating. This week-end is the start of the season with a short 200 meter sprint. This is an all out sprint from start to finish. All races after this are 500 meters. We train 3 times a week and races are extra. If you can talk at the end of a race you have not worked hard enough. A fantastic work out in the great outdoors!!

  26. I just did a wingate sprint session this morning on the trainer. 4 x 30 seconds max. Could barely make the full 30 seconds I was so toast by the end and had that puke feeling for a few minutes at the end there. I definitely will enjoy my 7-10 days before having to do that again haha.

  27. 4 x 30 sec bike sprints and I’m wiped.
    Many times I’ve read of people exceeding this number, and wonder whether they are truly gong all-out, or perhaps they haven’t developed the speed, strength or coordination to produce the wattage that would fatigue them more quickly.

  28. Sprints are phenomenal for the body! I would go to the local high school near me here in San Diego and do about 10 – 100 yard sprints. It only takes about 20 minutes, but I feel like I get more out of it than a 2 hr workout!

  29. I’ve been trying to lose weight for quite a while, and sprints work the best. No doubt about that.
    A 10-20 minute HIIT for about 3 days a week does more for me than 5 days of average cardio. But it’s just about getting to know your body, and what works best for you.