That being said, there are some common misconceptions about the activity patterns of hunter-gatherers and healthy non-industrial groups. They aren't (usually) couch potatoes, but they don't necessarily exercise a lot either. They range from very active to positively lazy, depending on the culture, the season and the gender concerned. Yet overweight is rare in all of them.
Consider the Kitavans. According to Dr. Staffan Lindeberg, the only overweight person on the whole island is someone who left for several years to live in a city. An average Kitavan man has a BMI of 20, which is very lean. Women have an average BMI of 18! A BMI of 25 is considered overweight and 30 is obese. The average Swede has a BMI of 25, the average American, 28. Kitavans have the activity level of a moderately active Swede, nothing more. They do the minimum amount of work required to grow their starchy tubers and fruit, and catch fish, all of which are abundant year-round. They are not restricted in calories.
Then there are the Tokelauans. Between 1968 and 1982, residents of the Pacific atolls of Tokelau gained roughly 11 pounds (5 kg) on average. This corresponded with a shift in diet from traditional Polynesian foods to a partial reliance on white flour, sugar and other processed foods. During this period, men exercised progressively less due to the introduction of the outboard motor, but the activity level of women stayed roughly the same. Both genders gained weight. Calorie intake didn't trend in any particular direction during the same time period.
Tokelauans who migrated to New Zealand saw a particularly large weight gain, gaining 22 pounds (10 kg) over the same time period. Their diet became even more Westernized than their relatives who remained on Tokelau. The authors of the Tokelau Island Migrant study felt that "most of the migrants expend greater energy in their work than is currently the case in Tokelau."
The "paradoxes" keep rolling in. In this recent study, investigators compared the energy expenditure of Nigerian and African-American women, using direct measurement (respiratory gas exchange and doubly labeled water) rather than questionnaires and observation. Here's what they found:
Mean body mass index (in kg/m(2)) was 23 among the Nigerians and 31 among the African Americans; the prevalences of obesity were 7% and 50%, respectively. After adjustment for body size, no differences in mean activity energy expenditure or physical activity level were observed between the 2 cohorts.Are you bored yet? Here's another one, just in case your eyes are still open. I'll quote from Stefansson's Cancer, Disease of Civilization, referring to traditional point Barrow Inuit women in wintertime. The section in quotes comes from the anthropologist Dr. John Murdoch:
"They are large eaters, some of them, especially the women, eating all the time..." ...during the winter the Barrow women stirred around very little, did little heavy work, and yet "inclined more to be sparse than corpulent"One last example. Americans have gained weight continually over the last 40 years, despite increasing leisure-time exercise and an increased energy expenditure. Our calorie intake has increased over the same time period, and the quality of our diet has deteriorated.
I think it's clear that the relationship between exercise and weight is not very tight. In my opinion, diet has a much larger influence on weight than exercise. Doing low-intensity "cardio" on a treadmill is almost totally ineffective for weight loss.
So can exercise help a person reach or maintain a healthy weight? Absolutely, but the type of exercise is critical. Exercise plugs into some of the same metabolic pathways as a healthy diet, normalizing hormone levels and increasing stress resitance. All you have to do is pop over to Chris's Conditioning Research to see a number of studies that compared chronic cardio (as Mark Sisson would say) to high-intensity, intermittent training (HIIT). HIIT is the winner every time by virtually every measure. Even though a person burns fewer calories sprinting on and off for five minutes than she does running for 30, she will still lose more fat and gain more muscle sprinting because of the metabolic shift that type of training produces.
In one study Chris posted, investigators compared the effect of two different exercise styles on fat loss and metabolic parameters. One group was assigned to low-intensity steady-state exercise, while the other was assigned to short 8-second sprints (called HIIE in this study). Here's what they found after 15 weeks:
Both exercise groups demonstrated a significant improvement (P less than 0.05) in cardiovascular fitness. However, only the HIIE group had a significant reduction in total body mass (TBM), fat mass (FM), trunk fat and fasting plasma insulin levels.I think exercise is part of the fat loss / maintenance toolkit, along with intermittent fasting. But nothing beats a good diet.
25 comments:
I think its interesting to note that many crossfit HIT style workouts are called "metabolic" workouts. The point isn't to burn calories. Its to have an effect on the endocrine system. Art DeVany has some great material on this issue as well. Devany and Sisson each recommend, in addition to the highly intense intermittent bursts of activities, long periods of very low level activity, e.g. walking. The place to stay away from is the middle zone, what Sisson calls, "chronic cardio." That just creates too much cortisol. Unfortunately, that's exactly where most people aim.
Great post on exercise. I totally agree with HIIT and its effectiveness at inducing changes in our body for the better.
However as toddhargrove said there is a place for cardio, probably not over 30minutes, because it is good for the heart.
I've lost over 20 pounds in 2 months with maybe a total of 10 minutes walking in a single day. For probably 16 hours a day I was sitting and the rest sleeping. My body fat went from 14-15% to 10%.
A few months before I change to a low carb diet I did some high intensity workouts. I would do 1 set to failure; usually 10-20 very slow reps depending on the body part. I did this once every 3-4 weeks, sometimes longer, and I upped the resistance with every workout. Total workout time would be around 20 minutes.
" Hunter-gatherers had a word for exercise: "life"."
Classic! I'm going to tween that.
Cheers,
Adam
Lovely; What ever sparked the interest in endurance exercises anyway? Sometimes I feel like people think they have to be in pain in order to be healthy; or have to use will power, just because that's what the media and other sources portray. No pain no gain. If your food tastes good, it's probably bad; if you're not weezing out of breath, you're probably not trying hard enough, etc. At least that's what I always thought subconsciously, for sure. And that's probably why America is full of people who are the most unsatisfied yet it's the biggest "diet" country - I'm unsure as if Brazil or America leads in bigger sales of dietary pills, but first or second, it's obvious people aren't happy with their weight, and they either try to find a miracle, or try to make themselves subconsciously miserable (i.e. "disciplined")
The BBC is making a documentary/show about people who must live and survive with the San Bushmen of the Kalahari in a remote part of Namibia. Do you know anything about this tribe? The show's focus is for sure diet, and the "paleolithic" vibe of it. Anyway, lucky british folk...wonder if it will show up on the BBC we've got in America, though most shows are at least a few years old that they air.
http://www.bbc.co.uk/pressoffice/pressreleases/stories/2006/06_june/01/diet.shtml
Oh, and Conrad, that's a great story.
Diet is 80-90% of the equation when it comes to fitness. I always like the example of a friend o mine who was a bodybuilder and he caught in contest shape without doing any cardio at all! just diet and weight training to keep the muscles. and no he didn't take roids, haha.
Stephen, just wanted to differentiate between a few exercise terms shown here and in the comments. Generally, the High Intensity Intermittent Training (or High Intensity Interval Training) is abbreviated as HIIT. HIT refers to High Intensity Training and is a bodybuilding method popularized by Arthur Jones where full-body workouts are performed each session by doing 1 set per each exercise at a slow pace with a high resistance load. This is what Conrad has described in the comments. Generally, HIIT (cycling high intensity sprints or movements with rest) is what a lot of the tests such as the ones on Conditioning Research are based on. In reality, they are very similar in process and results, but are referred to differently. Anyway, great post.
I've been able to lose weight in the past via long, slow cardio (although not maintain the weight loss). However, my definition of 'long' is 4+ hours of cycling or hiking. Anything less than that and you aren't burning through the carbohydrate reserve and mobilizing fat. And obviously since you are completely relying on fat reserves at some point, it has to be low-low-low-intensity (slow). Running and or jogging simply cannot be low intensity enough. Humans, being bipedal, are enormously efficient at walking over long distances but not designed to run for any length of time.
I would agree that 30-60 minutes of cardio is totally useless. It's just another way to convince your body to waste away, particularly when combined with a semi-starvation diet.
I probably work out for 5-10 minutes twice a week, mostly one-legged squats, one-arm push-ups, and pull-ups on a door. When 3 reps of a single exercise causes you to break out in a sweat, you know you're on the right track.
A while back Free the Animal posted a remarkable youtube of San Bushmen catching an antelope by persistence hunting. It took about 4 hours of mostly walking to catch up to the animal, which was so exhausted by then that the guy just walked up to it and killed it.
It's a relief to read that healthy exercising can be less painful, especially as I've been phasing out running (over 10 years!) and phasing in climbing. After only a month of climbing regularly, I can see more physical results (leaner, more muscle) than with running, and it's really fun! Also, it's so interesting to see how fit and muscular regular climbers are and to learn how loathe they are of cardio (they really really are). I have to twist arms to get my climber friends to go on a hike... even if it's just a longer access trail to a great outdoor climb. Besides planned work outs, climbing is really the epitome of a sport consisting of intense, but brief, spurts of energy. I do still still enjoy an intense 30 min run and some interval hill training, but no more than that and no more than a couple times a week. Plus, it'd be nice to avoid knee replacements when I'm old and grey.
I have a hard time believing that our H/G ancestors had only two speeds- a walk or a sprint. I know from experience that a slow run can be maintained indefinitely, covers a lot of ground and makes you feel great. Long fast runs (or biking) above lactate threshold (i.e., panting your lungs out) are not fun, at least not on an everyday basis. When people talk about "cardio" they lump every kind of supposedly cardiovascular exercise together, without distinguishing the different types (varying % of VO2max) and the different benefits from each type. Sprint training is cardio too technically. I love a good interval session and weight lifting too. But if you are trying to stimulate fat burning, you need to train for the long slow stuff too. And studies show that the athletes trained in endurance exercise were less likely to become overweight and diabetic later in life, compared with strength athletes.
Hormonal effects are certainly important, but the effect on different people varies due to their particular implementation. For example, exercising to glycogen depletion stimulates cortisol release according to some studies—but it's only been studied in people eating high carb runner's diets and therefore with the glycolytic processes well upregulated. In a carb restricted person with lower glycogen stores and upregulated fat metabolism, is cortisol released in the same way? It's not known. I saw my weight loss stalled when I started working on speed (intervals and long runs at higher heart rate), but not just from putting in the distance.
That said, I can also attest to the fact that long hiking/running by itself will not generate weight loss. It's not just calories in = calories out, it's what kind of calories go in.
sorry to babble on so long...
Cynthia
Chloe,
Yes, the San are one of the best-studied hunter-gatherer tribes. I have a book about them on my reading list. That show should be fun, although I wonder how modernized they are now.
Dan,
Hmm, that's interesting, in the literature they sometimes abbreviate high-intensity intermittent training as HIT, like here
. Do you think that's a mistake?
Cynthia,
I think you're right, some HG groups did run. The question is, was it helping their health or was it a stressor that they tolerated?
That's good to hear.
Also, I wanted to add; aren't some people "built" to run. I know more african tribes are longer and lankier because of the hot weather, making it easier for them to stay cool, rather then shorter and lankier then a tribe living in the cold weather. I assume it's easier to run with the lanky physique (correct me if I'm wrong). So I would have to ask the same question and wonder if it was just in them to run, or if it is or was a tolerable, unnecessary stressor (and who runs), since there are examples of other healthy groups that do not constantly run, given their environment. Running also makes you feel good because of the endorphins released, and that's not necessarily a good thing (addictive and raises cortisol) - I'm not sure if high intensity interval training effects those endorphins in the same way or not if done in a certain way. I wouldn't do it everyday, like you can walk everyday, but it seems the intense stuff is better off done less often.
I think everybody will agree that mandatory execution is a just sentence for spammers.
Let's start with "papia" above.
Trial is optional.
Stephen, no not a mistake. You could use HIT to refer to High Intensity Interval Training. It just seems that people refer to the interval training you described as HIIT in order to distinguish it from the bodybuilding method HIT (http://en.wikipedia.org/wiki/High_intensity_training). HIT uses resistance training only while, HIIT can use both. I just wanted to point it out so that people understand the type of exercise in the study. For example, Conrad posted a comment describing his workout, which is based around HIT. The thing is, they are both very similar in process and their effect on the body. However, HIT is primarily set up as a way to build muscle mass.
That meant to say:
HIIT can use both resistance training and cardio sprints.
I'm curious about what specific excersizes were used for this study that has been in the news recently. Seems too good to be true.
I think the point with endurance exercise is that, if it is done within your limits and abilities, it is not a "stressor." Children run all over the place. We're born to run about, fast and slow, rest for a bit, then do it all over again. When I am strong and healthy, I would rather run than walk.
Most of the people you see "training" are trying hard to get back to a state where such exercise is no longer unusual. And some may be shooting for higher levels of achievement than is really easy to reach, and thus may push themselves quite a lot with high heart rate training (like intervals). That's why it's better to be patient and take it slow, esp. if you're quite out of shape or overweight. It's great to alternate running and walking, and mix it up with sprints or other exercises like the Crossfit people do too, if you are ready for that.
Anyway, it also depends on what you mean by stress. I would contend that any out-of-the-ordinary stimulus can be stressful, and the reactions to the stress can be both beneficial and harmful. It just depends on what objectives you have. Exercise of most sorts will help improve insulin sensitivity and lead to more normal health and levels of body fat, even though that's not the whole story.
Dan,
OK, I'll edit the post then. Thanks.
Reid,
Yeah, it's pretty amazing. Here's what they did:
Sixteen young men (age: 21+/-2 y; BMI: 23.7+/-3.1 kg * m-2; VO2peak: 48+/-9 ml * kg-1 * min-1) performed 2 weeks of supervised HIT comprising of a total of 15 min of exercise (6 sessions; 4-6 x 30-s cycle sprints per session). Aerobic performance (250-kJ self-paced cycling time trial), and glucose, insulin and NEFA responses to a 75-g oral glucose load (oral glucose tolerance test; OGTT) were determined before and after training.
Cynthia,
I think it's relevant that children don't jog for 30 minutes, they mix spurts of walking, sprinting and jogging when they play.
You're right Stephan. Children are smart that way (but then so are soccer players). Sounds reasonable to me. :)
Stephan: "I think exercise is part of the fat loss / maintenance toolkit, along with intermittent fasting. But nothing beats a good diet."
I disagree. Good diet combined with max intensity exercise, weight lifting, and light exercise (walking, active sitting) will beat the hell out of any diet with no exercise. It goes beyond maintenance. Guys lie Art DeVany and Mark Sisson are more fit than 95% of the population and this means they have better insulin and glucose tolerance, lower triglycerides, lower C-Reactive protein, etc. There is no diet that can give you the metabolic effects of HIIT. It can cure Syndrome X and diabetes with no change in diet. No other exercise can do that.
efficacious: "However as toddhargrove said there is a place for cardio, probably not over 30minutes, because it is good for the heart."
Todd didn't say that. He said you should avoid the middle zone. There is no need for classical cardio. Interval training provides all the benefits and more, like reversing insulin resistance and similar problems. What I would do for the lower intensity exercise is walking and active sitting (Swopper stool, Muvman, Sitness 20, or a balance ball - in order of the most to least expensive option). Sitting motionless all day is bad, regardless of what you eat. Active sitting is a better choice than normal chairs.
The shoes you wear could also serve your fitness or hinder it. The best shoes are thin and flexible, Vibram FiveFingers is what Mark Sisson wears. Chuck Taylor All Stars are used by Pavel Tsatsouline (and many other body-builders). Another one I have heard of is Vivo Barefoot. A higher price option is MBT shoes. They recreate the feel of walking on sand, so you have to balance and stabilize more.
Cynthia: "I love a good interval session and weight lifting too. But if you are trying to stimulate fat burning, you need to train for the long slow stuff too. And studies show that the athletes trained in endurance exercise were less likely to become overweight and diabetic later in life, compared with strength athletes."
Interval training burns 9x more fat than aerobics for every calorie burned during exercise. There is no need for the "long slow stuff." Clarence Bass doesn't do it and Mark Sisson doesn't do it and Art De Vany doesn't do it. They are all in good shape with muscular bodies. Runners fall apart in old age. Athletes doing sprints and explosive strength (like javelin) do not degenerate as much as people running marathons and so forth. You can increase endurance with high intensity cardio and weight lifting routines. There's no need to waste hours of your week with running or swimming or biking at a low intensity when you can get more benefit by doing a lot less at a higher intensity.
http://www.cbass.com/FATBURN.HTM
http://www.cbass.com/Intensity.htm
http://www.cbass.com/Sprintendurance.htm
I have enjoyed reading your analysis of the studies on the Tokelau people both in the islands and in NZ. Thanks.
I am interested that without a great deal of fruit and vegetable intake they appear not to have a high incidence of cancer?? I make this assumption as there is no mention of it.
Does their great coconut consumption have something to do with this?
Are there any concerns about their lack of vegetable intake?
Marion,
An astute observation! They do eat some fruit but few vegetables. Many healthy cultures have a low intake of vegetables and fruit, including hunter-gatherers. I personally don't believe vegetables or fruit are a necessary part of a healthy diet.
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