Physical Activity: Whence Its Healthfulness?

In our last post, Exercise: Is Less Better Than More?, I quoted four studies showing that light aerobic exercise, of the intensity of jogging at 10 or 11 minutes per mile, improved health up to a volume of about 30 minutes per day, but then the health benefits plateau. Light aerobic exercise seems to become unhealthy as the volume exceeds 50 minutes per day.

Today I’ll continue looking at low-level activity to try to clarify where the health benefits come from, so that we can better design a health-maximizing exercise program.

Sitting versus Standing

There seem to be negative health effects from even short periods – a few hours – of inactivity: sitting or lying down.

A recent systematic review, first-authored by TJ Saunders of Obesity Panacea, found that a single day of bed rest is sufficient to raise triglycerides, and that 2 hours of sitting increases insulin resistance and impairs glucose tolerance – moving the body closer to a diabetic phenotype. [1]

Research by Marc Hamilton found that sitting shuts down expression of lipoprotein lipase (LPL) in skeletal muscle, preventing muscle cells from importing fat. [2] A Science Daily article shows an interesting video based on this research. Here are blood samples after consumption of an identical meal eaten the same person; the left sample was taken after a meal eaten sitting down, the right sample after a meal eaten standing:

When sitting, dietary fats are taken up only by adipose tissue. When standing, they are taken up by muscle and adipose tissue both.

Time spent standing did more to push fat into muscle cells than vigorous daily exercise. This is significant because pushing nutrients into muscle cells promotes muscle growth. If you have trouble gaining muscle, maybe the problem is too much sitting, and what you need is not more intense workouts, but more frequent standing!

Sleep Is Good

Not all inactivity is bad, however. Sleep is highly beneficial.

Consequences of poor quality or insufficient sleep include:

  • Higher rates of cancer. [3]
  • Impaired immunity and vulnerability to infection. [4]
  • Higher rates of heart disease. [5]
  • Higher all-cause mortality. [6]
  • Faster cognitive decline with age. [7]
  • Shortening of telomeres. [8]
  • Higher rates of diabetes. [9]

One way to interpret this: Inactivity during the day is unequivocally bad, but inactivity at night may be a good thing.

This may be an indication that the benefits of activity come not through fitness, but through entrainment of circadian rhythms. To enhance circadian rhythms, we want daytime activity but night-time rest.

Activity at Work

If activity and exercise at work are good, it might seem a good thing to have an active job. Why not get paid for getting your exercise?

However, the data is not so clear. In comparisons of sedentary work with active work, usually the sedentary workers come out pretty well. For example:

  • In women, no relationship was found between occupational physical activity and heart disease risk. [10]
  • In the HUNT 2 study, people with metabolic syndrome were more likely to die of cardiovascular disease if their work included physical activity than if it was sedentary. [11]
  • In the Copenhagen City Heart Study, high occupational physical activity was associated with higher all-cause mortality. [12]

It seems that when it comes to routine physical activity, more is not better. Exercise is a stressor, and it’s easy to get too much. Being active for eight hours a day is too much.

How Much Activity is Optimal?

If we can easily get too much low-level activity, then what is the optimal amount?

I suggested in my last post that we don’t have an innate “activity reward” system in the brain because our hunter-gatherer ancestors got more exercise than they needed. If that’s true, then we can look to hunter-gatherers to see what constitutes enough activity.

So how much activity did hunter-gatherers get?

It’s been estimated that hunter-gatherers typically walk 5 miles a day, run 1 mile a day, and do various resistance-style carrying and lifting activities. For instance, anthropologist Kim Hill states:

The Ache hunted every day of the year if it didn’t rain. Recent GPS data I collected with them suggests that about 10 km (kilometers) per day is probably closer to their average distance covered during search. They might cover another 1-2 km per day in very rapid pursuit. Sometimes pursuits can be extremely strenuous and last more than an hour. Ache hunters often take an easy day after any particularly difficult day, and rainfall forces them to take a day or two a week with only an hour or two of exercise. Basically they do moderate days most of the time, and sometimes really hard days usually followed by a very easy day. The difficulty of the terrain is really what killed me (ducking under low branches and vines about once every 20 seconds all day long, and climbing over fallen trees, moving through tangled thorns etc.)

The Hiwi on the other hand only hunted about 2-3 days a week and often told me they wouldn’t go out on a particular day because they were “tired”. They would stay home and work on tools etc. Their travel was not as strenuous as among the Ache (they often canoed to the hunt site), and their pursuits were usually shorter. When I hunted with Machiguenga, Yora, Yanomamo Indians in the 1980s, my days were much, much easier than with the Ache. And virtually all these groups take an easy day after a particularly difficult one. [13]

So the Ache walked about 6 miles per day, ran about 1 mile; other groups did less, but all of them traversed more difficult terrain than modern walkers and runners. So it seems that 5 miles of walking and 1 mile of running per day on easy terrain might be a reasonable estimate for the optimal daily activity level.

Five miles is about 10,000 steps. A review of the evidence suggested that 7,000 to 11,000 steps per day achieves all the health benefits of walking. [14]

In a comment, Jason gave us a link to a Runner’s World article that contained figures from a recent paper [15]. These illustrate the plateauing of health benefits at a relatively low level of activity:

Above about 30 MET-hours per week of activity, corresponding to 2 hours per week (20 minutes per day) of running at 7 minutes per mile or 4 hours per week (40 minutes per day) of jogging at 10 minutes per mile, there are no health benefits to additional activity.

In other words, the benefits of exercise run out after running 3 miles or jogging 4 miles per day – not far from the hunter-gatherer activity level.

The shape of this curve is supportive of the idea that circadian rhythm enhancement, not fitness, is the cause of the health benefits of exercise. Levels of activity beyond running 20 minutes per day do increase fitness – every cross country or track team in the country trains at a higher level than this – but do not improve health; so health does not depend on fitness. It looks like we need a certain amount of activity to properly entrain our circadian rhythms – to tell our bodies that it is daytime, the time of activity – but once we’ve achieved that, we don’t need to do more.

Centenarians Don’t Over-Exercise

Dan Buettner, author of The Blue Zones: Lessons for Living Longer From the People Who’ve Lived the Longest, has said, “None of the longest-lived societies we studied exercise as we think of it.”

And, based on my readings of centenarian obituaries, it seems true that the longest-lived often don’t do a lot of exercise. A reader who has commented as “B.C.” emailed me a link to a New York Times story on Julia Koo, a centenarian who recently celebrated her 107th birthday in good health. Her secret to a long life: “No exercise, eat as much butter as you like and never look backwards.” [16]


It looks like if we want optimal health, at least four factors should influence our daily activity:

–          When it comes to vigorous activites like running, jogging, or lifting, we should do neither too much nor too little. A half hour of such activity per day may be optimal for health, an hour or more may do us more harm than good. Thus, occupations that require physical activity throughout the day may be health impairing.

–          Several hours per day of walking is probably beneficial.

–          The rest of the day should be restful, but not completely inactive. We should not go more than 20 minutes without standing.

–          There are reasons to believe that the benefits of activity may derive more from circadian rhythm entrainment than from fitness. If this is true, then it may be important to develop a routine that includes some activity every day, than it is to optimize fitness by a well designed high-intensity interval training and on-day/off-day protocol.

It really didn’t occur to me until we worked on the new edition of the book that circadian rhythms might be the reason for the health benefits of exercise. (We have more evidence in the book for this idea, including the observations that exercise in the day improves sleep quality at night, and that circadian rhythm disruption has similar health effects to sedentary living.) Since working through this research, I’ve become much more committed to doing something every day – but much less concerned about whether that activity is well designed to make me fit.


[1] Saunders TJ et al. Acute sedentary behaviour and markers of cardiometabolic risk: a systematic review of intervention studies. J Nutr Metab. 2012; 2012:712435.

[2] Hamilton MT et al. Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes. 2007 Nov;56(11):2655-67.

[3] Nieto FJ et al. Sleep-disordered breathing and cancer mortality: results from the Wisconsin Sleep Cohort Study. Am J Respir Crit Care Med. 2012 Jul 15;186(2):190-4.

[4] Bollinger T et al. Sleep, immunity, and circadian clocks: a mechanistic model. Gerontology. 2010;56(6):574-80.

[5] Hoevenaar-Blom MP et al. Sleep duration and sleep quality in relation to 12-year cardiovascular disease incidence: the MORGEN study. Sleep. 2011 Nov 1;34(11):1487-92.

[6] Cappuccio FP et al. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010 May;33(5):585-92.

[7] Altena E et al. Do sleep complaints contribute to age-related cognitive decline? Prog Brain Res. 2010;185:181-205.

[8] Barceló A et al. Telomere shortening in sleep apnea syndrome. Respir Med. 2010 Aug;104(8):1225-9.

[9] Botros N et al. Obstructive sleep apnea as a risk factor for type 2 diabetes. Am J Med. 2009 Dec;122(12):1122-7.

[10] Mozumdar A et al. Occupational physical activity and risk of coronary heart disease among active and non-active working-women of North Dakota: a Go Red North Dakota Study. Anthropol Anz. 2012;69(2):201-19.

[11] Moe B et al. Occupational physical activity, metabolic syndrome and risk of death from all causes and cardiovascular disease in the HUNT 2 cohort study. Occup Environ Med. 2012 Sep 28. [Epub ahead of print]

[12] Holtermann A et al. Occupational and leisure time physical activity: risk of all-cause mortality and myocardial infarction in the Copenhagen City Heart Study. A prospective cohort study. BMJ Open. 2012 Feb 13;2(1):e000556.

[13] O’Keefe JH et al. Exercise like a hunter-gatherer: a prescription for organic physical fitness. Prog Cardiovasc Dis. 2011 May-Jun;53(6):471-9.

[14] Tudor-Locke C et al. How many steps/day are enough? For older adults and special populations. Int J Behav Nutr Phys Act. 2011 Jul 28;8:80.

[15] Chomistek AK et al. Vigorous-intensity leisure-time physical activity and risk of major chronic disease in men. Med Sci Sports Exerc. 2012 Oct;44(10):1898-905.

[16] James Barron, “Lessons of 107 Birthdays: Don’t Exercise, Avoid Medicine and Never Look Back,” The New York Times, September 24, 2012,

Leave a comment ?


  1. What do you think of the scientific claims in the book Body By Science? I’ve read high praise for it from strength trainers.

    • Hi Eric,

      I think it’s a solid approach to gaining muscle. An intense workout followed by 3+ days of rest is probably the most effective way to build strength, if there is overfeeding following the workout.

      I haven’t tried to appraise the health benefits of strength yet. But there are benefits to fitness even if it doesn’t improve health.

  2. What a fascinating idea that the real means by which exercises achieves its healthful ends is circadian entrainment rather than fitness attainment. Accepting that as true, and also accepting that infrequent, vigorous exercise is hormonally ideal, I’m afraid there’s still perhaps a bit of a catch, and it’s related to Eric’s question.

    Aside from hunter/gatherer, what in everyday parlance do we call someone who infrequently engages in vigorous exercise? A weekend warrior. On one hand it’s good news that the WW needn’t actually be fit.

    But the WW has another problem that isn’t hormonal per se: injuries. Vigorous exercise including hunting or in our case mimicing hunting is rough on the musculoskeletal system. The catch, I’m afraid, is that it might take actual fitness in order to safely perform vigorous exercise. Or in other words, doesn’t there need to be some transitionary mastery of movements between walking and running/sprinting?

    BBS’s answer is superslow, which seems like it should be safer. I’m not sure what the data supports. My uninformed take having read BBS and watched a few youtube videos is that its practicioners are seriously deluded as to their own level of fitness including pure strength and certainly as to anything that might be called athleticism. Of course maybe that’s alright if fitness isn’t the point.

    But I also suspect that heavy, slow exercise-machine lifting itself could lead to chronic stiffness and therefore pain and therefore ultimately disrupt sleep. At any rate, it should be interesting to flesh out how best to vigorously exercise infrequently, including how to do so without causing sleep-disrupting pain.

    Many thanks for the post!

    • Hi Shawn,

      Well, there are multiple types of fitness and superslow trains only a certain neuromuscular pattern. It’s not everything but it is something. I personally prefer movement and bodyweight exercises, but I think there’s no reason everyone needs to pursue the same type of body or pattern of fitness.

  3. Again “exercise” is assumed as activity in relation to economic practices. Hunter Gatherers dance and play all the time. Dancing can take place at night as can hunting. From the anthropology and archaeology I cannot find an evolutionary rationale for heavy lifting, but heavy lifting does seem to be beneficial to humans.
    I know two weekend wariors who have suffered heart attacks one fatal in the past six months. Both were in their thirties and had sedentary occupations, both engaged in crossfit/British military fitness type exercise. I supsect exercise like this fulfills a need in some people (men) that isn’t met by a nice hike through the woods.
    I would have thought that there would be a great many confounding variables in the studies on activity levels and health. Most physically demanding jobs are performed by people at the lower end of the socio-economic scale.

    • Hi Neal,

      Your weekend warriors are great examples of some of the health risks of seeking fitness rather than health.

      I think it’s desirable to build a base of good health before undertaking high-intensity fitness-building activities like military-style fitness. So I would try to engage in light daily circadian rhythm enhancement activities, and only when those are comfortable and refreshing — energizing like Todd Hargrove finds his — add in occasional (not more than twice a week for adequate risk) higher intensity fitness building activities.

      If you don’t have that baseline of healthful bodily function, then the stress of intense exercise may do more harm than good.

      I think you’re right that there are many confounding variables in studying occupational activity. Women’s work may not be as correlated between activity and income as men’s work, so that may be a better guide.

  4. Great article Paul. recently I’ve become very interested in the IMMEDIATE benefits of exercise as opposed to the benefits I will reap in a few days after my body adapts to the stress. I’ve recently started doing many little mini workouts throughout the day. Ten pushups here, five pullups there, or some bodyweight squats. It’s not stressful enough to increase my fitness so it doesn’t count as a “workout”, but it does keep me very energized and physically comfortable and less stressed throughout the day. I also think that people might be more motivated to move more if they thought the movements had some immediate payoff in small amounts as opposed to only being meaningful at some high threshold at some future time.

    • Hi Todd,

      Yes, I think that’s the most healthful way to exercise. I’ve been adopting a similar approach myself – I go out for a short run plus track-and-field warmup exercises (karaoke, high steps, a-skips) around the block, or do a few pushups/pullups/squats. Just 2 to 10 minutes at a time, but I try to make it add up to 15-20 minutes a day.

      I’m certainly moving more since I adopted this approach.

      • Very thought provoking info. Thanks to Todd for posting your link on FB, glad I found this site. Todd – what you’re doing sounds similar to something Pavel talks about in the Naked Warrior. A few reps of pullups, pistol squats, etc throughout the day…”greasing the groove”; getting stronger by frequent, non-fatiguing mini-sets of an exercise with a major focus on technique. (now if only my hips had the mobility to get low in a pistol squat 😉

      • karaoke? singing? Do you have a video? 😉

      • I take two 15-20 minute “brisk” walks at work, the routes I choose take me up (and down) 12-20 flights of stairs a day. I do it to music, so that I keep a steady pace. For me, it’s like dancing on my breaks. I really miss it when a meeting gets in the way. 2 and 1/2 years ago, I could not go up, nor safely down more than one flight of stairs, and I alawys had to use the hand rail. I also switched to a standing desk last year, and now I HATE sitting at a computer. Aside from eating, and rides in vehicles, I rarely stay sitting down for long anymore. Our office is moving, and I’m dreading the doubling of my car-based commute time.

  5. “From the anthropology and archaeology I cannot find an evolutionary rationale for heavy lifting”

    Hunted animals have an inconvenient habit of not dying right next to one’s campfire. Furthermore, when one is armed with spears or an atlatl instead of a high-powered rifle, animals tend not to die instantly, instead heading for cover or water.

    Also consider that humans preferentially hunted megafauna throughout most of our history (until we ate it all).


    • Hi J,
      From what I have read animals tend to be dismembered then carried back to camp or if the animal is large enough the entire group set up camp around the animal and consume it until it is gone. Duffy desribes many ituri pygmiy groups travelling to have a large party when an elephant is killed.
      I can single rep deadlift or squat far, far more than I can carry for several kilometers.

  6. Hi Paul,

    As you’re on the topic of exercise and I noticed people on the previous post and here were asking questions about the BBS style high intensity RT approach I thought I’d share the paper I wrote with my colleagues and Doug McGuff recently.

    Also I’d add that just because there is no evolutionary rationale for perhaps a particular exercise mode to employ brief high intensity activity doesn’t mean we can’t consider the available modern evidence we have on effectiveness and safety of certain approaches and come to a decision as to which is most optimal.

    • “I’d add that just because there is no evolutionary rationale for perhaps a particular exercise mode to employ brief high intensity activity doesn’t mean we can’t consider the available modern evidence we have on effectiveness and safety of certain approaches and come to a decision as to which is most optimal.”

      exactly what I meant

  7. So if its tied to circadian rhythms is there a certain point during the day when exercise would be bad? After dinner?

    • Hi Christina,

      Good question. I don’t think that’s been tested.

      I see that as one of the issues of a modern lifestyle. Eating after dark and exercising after dark are probably both a bit disruptive to circadian rhythms — not ideal — but it’s hard to avoid them in our modern lifestyle.

      If health optimization were our goal, people would eat and exercise in the morning and mid-afternoon, and work for maybe five hours mid-day and three hours in the evening before bed.

      That schedule doesn’t fit into a daily commute, however.

      As it is, I think maybe 10 minutes of light activity (eg running/jogging/pushups/pullups/squats) in early morning before work and 10 minutes either at lunch or in the early evening before dinner would be about the best most people could do, with maybe a walk after dinner.

  8. Thanks for this, and nice to bring up the circadian rhythm, interesting!

    I always thought Art De Vany’s power law approach to physical activity very useful. I’m not qualified to interpret the math of power laws, so maybe it is just a metaphor.

    And I agree with Todd Hargrove on the issue of immediate effects of moving.


    • Hi Pieter,

      Yes, I think Art is right about the power law. One of the things I was trying to do was quantify what that means for each level of activity. I get something like:

      – Rest – up to 65% of the day (eg 15 minutes out of every 20 not engaged in activity)
      – Standing/squatting/active rest – at least 25% of the day (5 minutes out of every 20)
      – Walking or yoga-style stretching or other light movement – 8% of the day (2 hours)
      – Jogging or running or active yoga or similar – 1.5% of the day (20 minutes per day)
      – High intensity intervals or resistance training – 0.5% of the week (~ 1 hour per week)

      I think that is roughly what the literature suggests is most healthful and it does follow Art’s power law.

  9. Here is a fun sitting info-graphic:

    Good post Paul. I was just thinking more about this the other day.

    For a long time it has bothered me how all-around bad I feel later on in the day at work – lethargic, eye-strain, foggy brain, etc. I kept thinking it was too much/too little coffee (lol), an environmental factor of some sort, etc. Maybe I just sit too much? Perhaps I’ll set a timer to get up and take a walk every 20 minutes and see how I fare.

  10. When sitting, dietary fats are taken up only by adipose tissue. When standing, they are taken up by muscle and adipose tissue both.

    Interesting, reminds me of Tim Ferriss idea of doing a few squats before a meal.

    • Hi Mark,

      Shou-Ching says there is an old Chinese saying: If after a meal you walk 100 steps, then you will live to age 99.

      Might be the same idea!

      • That’s very interesting — both the saying and Ferris’ little idea. I have often found that after consuming a large(ish) meal, I have a very strong desire to do a bit of vigorous exercise, as though my body wants me to feel as though the food is going to be put to some type of good use. I find very few people who agree with me on this! Most people experience some sort of “food coma,” as they call it, but I really always want to go lift things.

        I’m sure this is mostly mental — the “food as fuel” idea — but, as with most things, the physical/mental difference is unclear at times, and perhaps not always important anyway. If moving feels good, do it.

      • There is also a word for this in German: der Verdauungsspaziergang. It’s translated as “after-dinner walk,” but a more direct translation would be a walk that aids digestion.

  11. I am wondering about the division of labour between women and men in the Hunter Gatherer societies. Is it a fact that men did most of the hunter work and the women did the gathering? If this is the case did men and women evolve much differently in terms of how they respond to exercise?

    • Good question. I don’t know but it seems evolutionarily plausible that men may fare better than women with high intensity exercise, walking and carrying might be sufficient for women.

      • The idea of “men hunt and women gather” is a myth among hunter-gatherer societies. The division of labor among the sexes did not begin until the late stone age. Paleolithic men and women both participated in the hunting and gathering of foods. The flexibility of labor between current hunter-gatherer societies still exist.

    • Hey Ian,
      Yes and no there is some evidence that neanderthal women exhibit the same pathology as males thought to come from hunting practices. Females in some hunter gathere societies do a fiar bit of hunting.
      Digging for tubers is also particularly hard work, in fact it is the closest I have seen to tabata style workouts in the literature.

  12. Of course if you have varicose veins, moving around a little bit is better than just standing still.

  13. Thank you for a great article!
    It is full of well-explained information!
    It does help to reduce to much activity!
    What do you think is the best time per day for iust walking? Many people prefer just to walk daily.

    • Hi Rachel,

      I think any time is good for walking, but since it’s desirable to get sun exposure (for vitamin D and bright/ultraviolet light entrainment of circadian rhythms) it should be in daylight hours outdoors.

  14. So, standing desks, yes or no? Should you have a standing desk with a stool to lean on/rest? Or, stick with a regular desk, but stand up and walk around every twenty minutes? Like many people, I have a desk job and have been thinking about transitioning to a standing work station.

    Also, eating while standing appears to be a good thing…

    • Hi Pook,

      I think standing all day is bad.

      What I’ve done is elevate my desk on cinder blocks so that it puts the keyboard at the right height for standing. Then I have a piano bench which is about knee height which I can kneel on, and a draftsman’s chair which is about butt height so I can sit on it and type. I alternate through the day between sitting, kneeling, and standing. The monitor is on a maneuverable arm so I can adjust monitor position and angle a bit whenever I change position.

    • I think Paul has mentioned before elsewhere that a standing desk might be beneficial. I have been meaning to order one the last few months but have procrastinated. But with this post of Paul’s as my inspiration, I am off to amazon to see what I can find.

      • Hi Thomas,

        I think standing all day is as bad as sitting all day. Variety in posture and movement is important. Ideally the joints should go through their full range of motion in a day. I’ve found now that I do more standing that some sort of yoga to get into bent postures is important.

        • I break up my standing with sitting at meetings & lunch. I also sit on tables when we have ‘group’ discussions in our work area, and I take extra short walks to make tea, recycle my water bottle, or deliver a report to someone.

    • Along these same lines, do we have any reason to think that it’s beneficial to move around a bit WHILE sitting? I frequently will restlessly jangle my legs around, especially while I’m absorbed in thought.

  15. Ah, I should have hit refresh before posting, and I would have seen Paul’s 9:40 response.

  16. I think the ideas of Phil Maffetone would also be helpful to consider. He advocates building an solid aerobic base prior to any anaerobic exercise by training an “aerobic” heart rate found with the formula 180-age (with a few additional considerations). It seems to be a very low HR but persistence over 3 to 6 months leads to significant improvements in performance at this reduced HR. When aerobic fitness is established, then anaerobic activity is added back in. Here is a link to Mark Allen’s experience with the Maffetone method:
    Perhaps the problem is aerobic exercise is often too intense for beneficial adaptations to occur.

    • Ward, I had Dr. Maffetone in mind with my comments above about the risks of anaerobics performed by the unfit. Here’s a piece from Clarence Bass speculating about compatibility between Maffetone and BBS.

    • Great point Ward. Neal Matheson’s comment above about the weekend warriors who trained anaerobically without a healthful foundation are on point. I agree with the general philosophy, though I’m not specifically familiar with Phil Maffetone’s recommendations.

  17. Joshua Whiteman

    I work shipping/receiving for a retailer. My work days are 8 hours. Most of the work is standing based, but with movement. I have access to a chair and sit down when need be. Working at the back door, allows me to see the sun and venture outside from time to time. Occasionally, I lift heavy boxes and pallets. I also, walk in short burst, quite a bit. Lately, I have cut out all exercise and feel what I get from work is sufficient. Do you think adding in a day of HIIT style cardio,and one day of intense weight training will be sufficient? Do you think 2-3 days of moderate intensity,stationary bike ride, would be okay? Is it the standing in place, that you feel is bad or just standing period? Sorry for the plethora of questions, I am just very curious, on this particular subject. Thanks and have a good one.

    • Hi Joshua,

      It does sound like you plenty of light activity at work.

      If you want to add to it, you might find something meditative like yoga or tai chi to be a good complement. Perhaps a day with some running or biking and a day with a HIIT style workout would make sense, but I wouldn’t do more than two workouts a week that are tiring. Most workouts should be restorative, like yoga.

  18. Once again, more than half the sky is left out of the equation. Why are we only talking about hunters? As if hunting was the most important activity! Bah! As if hunting was the most important activity that men performed! Ha! As if men are the template for “people”! Gah! None of this speaks to my life experience. Here is just one example: I’m 58 yrs old and I have spent most of my adult life carrying children, (while doing nearly everything else that I needed to do). My kids loved to be carried! Even when they were 6+ yrs old they would ask to be picked up and held. For years I carried the smalls and the bigs at the same time. I picked them up and put them down all day long. I carried my own kids, foster kids and now grandkids. I hope to be carrying kids for many more years. Talk about it.

    • Sounds like you’ve gotten plenty of exercise! May you carry many great grandkids.

    • I was just thinking along these lines. My one year old is 24 pounds and only getting bigger. At this age even a child that likes to play independently needs to be picked up at least every ten min for some reason or another. And carried. And jiggled around. It is interesting that the number one means of exercising for women, child care, is not mentioned or taken into account at all. They just don’t let you sit down for more than 10 minutes when they’re young. I do see this aspect missed by many of my favourite paleo bloggers. A lot of them are childless, which would not have been the case for the last million years.

  19. Wonderful article Paul, thank you.

    When trying to figure out how much to limit exercise, I wonder if “listening to your body” may be a good strategy? It sounds like in Kim Hill’s experience the Ache and the Hiwi both used rest days based on how they felt.

    I have taken up running this year, but your book and other paleo sources made me aware that I had to be careful not to overdo it. I’m amazed at how often minor “symptoms of overtraining” crop up, warning me to take it a little easier. What would be really good to see is a thorough science-based list of such symptoms, especially more early-warning ones! (I bet the the average semi-competitive modern runner waits for his ‘tired’ feelings to get a lot worse than the Hiwi & Ache did, before taking a rest day!)

    One note, although it’s useful for general discussion, using running paces like 7 min mile or 10-11 min mile to denote intensity is not very accurate; intensity at a certain pace is completely dependent on running ability. For me an 8 min mile is a jog (~140 HR; 70-75% of max HR), while a 6 min mile is a run (my 10K race pace).

    • Hi Mike,

      My experience as a runner is that it takes some time to build up fitness, and it’s important to be patient and not get those overuse injuries.

      I agree that everyone is different for pace.

      I think one measure of overtraining is: after the workout, do you feel refreshed, or do you feel like you need to recover? The latter feeling you should have at most twice a week, and it should go away within 24 hours. Most days your workout should refresh and energize you.

  20. Dear Paul,

    I would like to get all the health and longevity benefits of an active life and a low-protein diet. My activity routine is about what you recommend – lots of low-level activity, some moderate, and HIIT every 5 days. But I am totally confused about how much protein I need. Should 0,8 g per kg be enough or do I need more?
    Maybe the high protein intake of athletes is the reason why there seem to be no big extra benefits from intense exercise.
    I also do alternate day fasting. Does that have an influence?
    Keep up the great work!

    • Hi Michael,

      0.8 g/kg is a fairly minimal protein intake. It should be adequate for health, but you are likely to find it easier to build muscle if you eat more.

      Is this the average over fast days and feeding days?

    • There has been some research regarding protein intake, and the sweet spot appears to be 70-120g of protein a day depending on your body weight. You don’t need to eat a specific amount each day, as long as you hit that average throughout the week. If muscle weight is desired, creatine seems to be one supplement with lots of studies to back it, Creatine works much better along with average amounts of protein, than merely eating more protein would.

  21. Paul, you must sometime check out the Alexander Technique, or perhaps Feldenkrais.

    I took lessons in the Alexander Technique, and it’s one of the best things I ever did for my health. For my money, it’s as valuable as going primal or paleo.

    It is much easier to stand for longer periods of time after you take lessons, or to do any activity, for that matter. It enables you to feel more comfortable in your body, move more easily, and banish stress.

    Knowing what I know about all this, I still need to get up from the computer more often. It’s easy to forget!

    Here’s my own personal experience with taking Alexander Technique lessons. I write online as gracenotes. Note that there are no commercial links on my article, nor am I an Alexander teacher!

    What It’s Like to Take Lessons in the Alexander Technique

    • Hi Sherry,

      Thanks, your journal is very interesting. Makes me want to take lessons!

      Both Alexander Technique and Feldenkrais have been recommended to me in the past. I wish I had more time to explore these things.

      Best, Paul

    • Sherry

      If you’re already practiced in standing for long periods, may I recommend you don’t “get up from the computer more often” at all, but stay upright and use a standing desk:

      I prop my laptop on a plastic footstool that cost me 3GBP (<5USD) and have a very pleasant view down into my back garden. Whether I stand or jiggle from foot to foot, I'm putting a lot less stress on my back and burning more calories over time.

      Wishing you lifelong health, naturally


  22. Hi Paul,

    thanks for your answer.

    yes, 0,8 is the average. Studies like this one:

    Long-term effects of calorie or protein restriction on serum IGF-1 and IGFBP-3 concentration in humans

    have convinced me that keeping protein to a minimum is very very important for longevity. Fontana recommends consuming 0,7 to 0,8 g per kg.
    So I don’t want to lose these benefits by consuming too much protein in general or after workouts.
    Also: since starting my low-activity routine I need to consume lots of calories (around 3000, maybe more) just to keep my BMI from falling below 19,5. So my protein intake is only 7 percent of calories. I wonder if thats a problem.

    Best, Michael

  23. I love the idea of sprinkling short bouts of various kinds of movements throughout the day. I have been making a point of walking each morning before breakfast….started out with the Maffetone method of tracking my hear rate…but I will be 70 next month and it is fairly hilly around here, so it was pretty difficult to stay low enough. Too stressful. So now I just walk at a comfortable pace, enjoy the countryside and go even slower on the hills.

    I spend a lot of time standing in the kitchen but for the last day or two try to make it a point to do short bouts of various kinds of movements every hour or so. From marching around the house with very high or long steps or lunges, a ittle chi gong or yoga, some kettle bells, or rebounding etc. So far it seems to energize me. Mentally and physically. And I think this method is helping me getter a better sense of what I need, rather than someone else’s idea of what I should be doing.

    A recommendation for those in offices is to get the portable miracle ball method.
    I love the routine in there of 5 movements to do without the ball…very helpful in the evening for getting good sleep, but useful anytime of day. And there are things to do with the ball that you can do at your desk.

  24. Paul, have you reviewed these pathology reports of Masai and Innuit’s coronary vasculature?

    Here is an audio clip of Cordain addressing some of the studies

    The first one is a little long but it’s showing that a young Innuit lady had extensive coronary plaque without evidence of rupture. Not optimal. Do you think in light of this data we should consider modifying our saturated fatty acid intake?

    Do you suggest that being somewhat mobile can attenuate it? I know the Masai are fairly active but not long distance wise.

    I look forward to your interpretation of this.

    • Hi Casey,

      Thanks for raising an interesting topic.

      Chris Masterjohn has discussed some issues with the diet of the Masai: It may be that the Masai who eat more saturated fat have less atherosclerosis than those who eat less saturated fat and more sugar and wheat.

      Re the Inuit, you might want to read my post on blood lipids in the Inuit, in our hunter-gatherer cholesterol series: They had a heavy burden of parasitic infections due to eating raw seafood that was full of parasites. They also had tremendous amounts of smoke in their lungs due to fires in small enclosed shelters. They also had a very unbalanced diet with serious nutritional deficiencies due to the lack of plant based foods.

      So this data is interesting, but it doesn’t tell us much about saturated fat.

      • HI, I can;t open PDFs on my truly palaeolithic computer. Can you point me out to further information on inuit nutrient deficiencies?
        I would say that stress, especially chronic stress is also atherogenic.

  25. Hi Paul,

    I’m wondering if sitting to have a meal and then standing for most of the time afterwards will have similar effects to standing while eating?

    I have a standup desk but unfortunately I normally sit the hour after I have lunch. Since I read this article I started standing after meals (thanks for interesting and practical post!), so I’m wondering if that’s enough (I normally have lunch with coworkers and friends, which is strictly a sitting down occasion ;)).

  26. Interesting article, Paul. I find, as time goes on, that I should (almost) always follow my own intuitions. Five or so years ago before I became interested in fitness and then paleo dieting and then the rabbit hole that has since ensued I always thought people with gym memberships were weird. I firmly believed that one could get easily get all their necessary exercise just by living their daily lives. I tended to walk everywhere, stand at bars when out with friends (even though they were all sitting), take the stairs instead of the elevator, do very occasional push ups, etc. I was always pretty thin so I don’t know what the heck I was thinking getting a gym membership! In the last five years I have become extremely active, working out sometimes for 2 hours a day, training for races, lifting heavy weights, etc. Not surprisingly, about 6 months ago I started to slowly gain weight despite my constant exercise and meticulous eating. Additionally, I always felt stressed, on edge and damn near about to explode. So, of course, I would go on a run to temporarily relieve stress.. Ha!

    Anyway, I have finally come back to my senses and about 3 weeks ago stopped “working out.” I have gone back to exercise that is included in my daily life such as walking to the grocery store, taking the stairs, going for longish walks on the weekend and doing occasional sets of pull ups or push ups throughout the day. That, coupled with heavily increasing carbohydrates has calmed me way down and caused me to lose about 7 pounds. Remarkable really what we can achieve when we listen to our bodies and try to ignore the latest thing in the paleo sphere.

  27. Joshua Whiteman

    Hey Paul, your comment about doing tai chi got me thinking. Lately I’ve been doing daily intermittent fasting with bulletproof coffee. I eat only one decent sized meal a day. However, I feel the urge to sit and rest after the meal. I wonder if taking up a light tai chi routine after my meal would be beneficial? Either way, tai chi is on my list. Thanks and have a good day.

  28. Paul, Don’t rely on Buettner as a reliable interpreter of his own data. In his TED video How To Live to be 100+ , he repeats the claim that the (very few) communities identified as Blue Zones don’t exercise, “at least the way we think of exercise”…right off the back of two centenarians shown taking a regular morning swim in one case and working out daily with weights and a stationary bike in the other. Since the first wasn’t diving for pearls, and the second wasn’t hefting sacks of potatoes or cycling to work, that is most certainly how I think of exercise!

    But I accept his point that the non-US Blue Zoners have a lot of physical activity built into the structure of their lives: squatting instead of sitting, growing much of their own food etc. Nearly all of us could do with more of this, e.g. by jettisoning our TVs and cars, or at least rationing their use, to raise our the baseline of our physical output.

    Wishing you lifelong health, naturally


    • Hi Ivor,

      Yes, I think most centenarians probably did enough activity to get near the circadian rhythm setting, health-optimizing level that hunter-gatherers did.

      I mentioned the Julia Koo story about her 107th birthday party. In that story she dances and tells the band to speed up the music. Her motto may have been “no exercise,” but I doubt she was inactive.

  29. The benefits for improve health with proper diet to taking sleep …meditation is the best part for fitness.Good suggestions for stress reduction.

  30. Hi Paul,

    Great article. I have a question.

    You stated that above about 30 MET-hours per week of activity, there are no health benefits to additional activity.

    What are the minimum MET-hours per week of activity that would yield health benefits?

    PS: Please include a MET table in the new book.

    • Hi Palo,

      The book is already finished, it’s too late to add to it.

      The benefits seem to be more or less linear up to 30-35 MET-hours per week.

      • Thank you Paul.

        One more question. Is there a minimum number of days per week to spread the 30-35 MET-hours? What do you recommend?


        • I think this level should be spread evenly over all 7 days, to accentuate circadian rhythms; then once you are adapted to this, add in additional brief but intense activity on an intense day / 2 rest days schedule for increased fitness.

  31. Hi Paul- I do daily 16 hour fasts and 2-3 times a week it is followed with alternating BBS/weight lifting/Crossfit workout. I understand and follow your post workout meal suggestion, but would like your recommendation for an optimal pre-workout meal/shake and it’s timing. I am assuming a pre-workout meal is required due to depleted glycogen stores from the overnight fast. Or is a completely fasted intense workout OK?

    • Hi Tod,

      I think a fasted workout is OK. You might want to eat a small bit of protein before the workout — say, one egg.

      If you were doing a long-distance run, say 10 miles or more, then I might say you should eat carbs beforehand. But I think with Crossfit it’s OK to exercise fasted. Lack of glycogen may impair performance a bit but it will improve fat oxidation and if you eat carbs immediately afterward you’ll relieve the stress on tissue.

      • Thanks Paul! A followup question: I know you have stated the importance of overfeeding to build muscle after an intense BBS type workout. How many carbs should be consumed post heavy workout to relieve the stress on the tissue? Post workout, I am drinking a whey protein shake, followed by a starch and solid food protein. I would like to maximize my results from heavy lifting. Thanks!

  32. This is kind of interesting and related. the average amish man walks approx. 18000 steps a day.

    • I really like the idea of building stealth exercise into your daily routine so that it’s not recognized as such. I spent the summer in Europe following PHD and foregoing driving altogether and returned much healthier and lighter than I’ve been in decades. Now, when time’s not critical, as a matter of course I’m beginning to park my car 1/2 mile to a mile away from many of my destinations and walk the remaining distance, and these parking places and walks are becoming increasingly habitual and normal to me.
      P.S. Just as a side note that may or may not be of interest, I’m also continuing to use a great, simple little gizmo that, used just a few minutes every day, has made a real difference in lean muscle tone, and probably bone density as well, called the ‘steel bow’. And it can easily be taken along when you travel, too. I’m not being a salesman when I say that I really love this simple, well made gadget for maintaining one’s musculature.

  33. Thank you for this article. I found it very rewarding, and very much appreciated the thread of comments from your following. A couple of things I have noticed since I have lived in Costa Rica now for over seven years, and have fully integrated into a different lifestyle that automatically includes more activivty due to the weather, and spread out nature of the town in which I live.

    1. People in Central America walk everywhere, and there really is no replacement for the steps taken. Growing up I remember driving to the grocery store that was three blocks away, this is an absurd idea in comparison to where i live now.

    2. There is no replacement for Fresh Ingredients and local products.

    3. Quit Rushing to get where your going, so as to only rush to get out of that moment. Enjoy taking your time with things..almost anything can wait for the extra two minutes of stress it causes you to hurry, your not really saving anything.

    4. Mediation, and silence is a key to keeping yourself going and not getting overwhelmed.

    5. Take a lot of Ciestas (naps).

  34. So what should the average day be made up of. If we are not sitting for more than 4 hours a day, and we are awake for 15, then we are standing and/or walking around for 11 hours a day? That seems like quite a lot of physical activity and more than the 5 miles of walking our ancestors did. Also a lot more than the 8 hours of physical activity we should avoid. What about driving, attending school lectures and watching a simple movie? What is a more realistic ideal?

    • Hi Kelly,

      I think you can sit for more than 4 hours per day, but you shouldn’t have long unbroken stretches of sitting, and should strive to sit in different postures and formats, ie squatting, crosslegged, foot on a footstool, etc. A good rule of thumb is to get up and move at least once every 20 minutes.

  35. Hey Paul

    On the topic of physical activity I just wanted to ask about fasted weight training and food intake.

    If your eating around 1000 calories carb+protein ( 300-360 protein, 600-700 carb) is their really much need to add in BCAA pre workout? Don’t amino acids circulate for quite a while, making fasted workouts pretty much safe?

    Also, if I was to workout fasted with no BCAA supplementation pre workout at around 8am,I’m wondering how soon after should I eat. With a short low volume workout glycogen stores won’t be too depleted and therefore cause catabolism so could I just continue my fast until noon lunch. or would a snack of two bananas 1-2 hours post workout be good. Is it vital to have a full meal of protein/carb/fat post workout; I can’t really eat a proper meal until noon due to work so I have to go with just some fruit as a snack till then which only provides carbs but no protein/fat. Im guessing that as long as I eat 1000 carb+protein calories daily, nothing too bad would happen as long as fasts are kept to 16-20 hours and no longer.


  36. Shieldmaid’s Guide to PaleoWorld | Shieldmaid - pingback on May 31, 2013 at 7:52 am
  37. Using data from the National Center for Biotechnology Information, here’s a calculator which visually displays the caloric difference between sitting and standing at work.

  38. This is so true. My grandmothers never did anything more than jitterbug a little, garden, and the occasional senior exercise or swimming class. They did it for pleasure, and I never saw either one striving or straining in the name of fitness–or for any other reason, come to think of it! So different from what we’re told to do: max out, burn up, hit personal records then set new ones, get hardcore, etc, etc.

  39. What would a beneficial rebounding session be like in length and intensity if doing to help with fat loss, based on these observations?

  40. Hi Paul, Hi Shou-Ching,

    I am a follower of PHD for 18 months with a great experience. Thank you for your research and sharing this very important information with the world.

    I was hoping to extend your perfect health approach to fitness. Having read your Clean Blog entry recently ( I was interested to learn more about the exercise regime you refer to (you mention push-ups, pull-ups, etc.)

    Do you have a particular approach or resource that explores perfect health fitness/exercise?

    Look forward to hearing from you as to my research this is not something you have previously elaborated on.


  41. Hi Paul!
    What do you think about the “Endurance running hypothesis”? It seems our body is built to walk AND run, not only to walk. If our ancestors didn’t run much these characteristics couldn’t evolve?!

    And I have another question: there are studies suggesting a potentially harmful effect of antioxidants supplementation, e.g.
    You recommended in your book vitamin C in larger doses, which I agreed with, but what about such opposite studies?

    Greetings from Budapest, Hungary!

    • Hi Isti,

      I think it’s a plausible theory – I think running was important but not convinced persistence hunting was significant for much of our evolutionary history.

      I’ll do a blog post on the vitamin C – there are an equal number of studies showing no negative effects from vitamin C; and even in the studies showing an effect, it’s tiny, whereas the benefits are very large in case of deficiency. So I don’t think it affects our advice. Note that animals are very strong with much higher daily production of vitamin C than our supplement recommendations.

      Best, Paul

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