You know I've been reading this board for a number of years and one thing is starting to stand out. A lot of people say, oh I changed this, I changed that and starting losing weight again. All the changes seem to vary. Some people up their carbs, some people lower them, some do IF, some up their calories, some restrict them further, some up their fat, and the list goes on. And of course that applies to exercise as well.

I'm starting to wonder if it's not so much what you do as the fact that you changed something. Well obviously that doesn't apply to everything. We'd be so lucky to lose weight on a diet of cheesecake and danishes, but I'm starting to wonder if I'm not right.

For exercise it seems to be pretty well accepted that interval training is best. That your body gets used to a certain routine and stops responding. Maybe it's similar for weight loss?

I find this the more interesting question. Not does exercise facilitate weight loss by burning calories? But does exercise facilitate weight loss by changing hormones?

The jury seems to be out - as far as I can determine. I wonder if the answer is inconclusive still because some of us lose weight from exercise and some of us don't.

Hmmm..interesting thought! Very very possible!

Body By Science, by Doug McGuff.

Interesting. I was looking at Taubes again this weekend. He cites a study that shows that 3-month-olds with lower metabolism are more likely to become obese later in life.

I was a slim child and teen, becoming heavier as an adult. When I was 16 I was at my full adult height of 5'6" but weighed only 116 lbs. My parents always complained that I didn't help out around the house as much as my sister did (which wasn't true, BTW!). One day my dad came into the living room and saw me sprawled across the couch as usual, and he said thoughtfully, "You know, it isn't that you work any less than the rest of us; it's just that when you're relaxed you're so relaxed."

I'm wondering if that was a forewarning of my weight gain. I know it's always been my policy not to stand when I can sit and not to sit when I can recline.

I think that you are absolutely right...change something!!

In my experience, my body is great at adapting to what I am doing. Over time, and by staying consistent to my plan, I did have to change things up here and there to keep my body guessing.....and losing

How could it not? If excess fat stores are hormonally driven, anything that affects those hormones will also affect fat stores in some way.

Mark Sisson's Primal Blueprint and "Primal Body Primal Mind" by Gedgaudas both talk about using the right kind of exercise at the right times to manage how your body partitions and uses food.

Well, first off you have to assume that exercise affects hormones. And then you have to assume it affects hormones having to do with energy usage. And then you have to assume it affects them in a positive direction.

Growth Hormone is stimulated by HIIT. In men it stimulates testosterone as well. A thyroid gland not producing enough T4 is a big cause of weight gain in animals.

GH and testosterone are anabolic, they cause muscle growth while using your own fat to supply the energy for the process. T4 deficiency slows all facets of metabolism. No energy for exercise leads to weight (fat) gain. Lack of insulin causes severe weight loss in type 1 diabetics. In normal people it is anabolic similar to testosterone and GH.

Hormones have a profound effect on weight gain or loss.

I don't know. Everyone's got a book to sell.

This from an article by Taubes:

"Meanwhile, the evidence simply never came around to support Mayer’s hypothesis [that physical activity would lead to weight loss], even though our beliefs did. My favorite study of the effect of physical activity on weight loss was published in 1989 by a team of Danish researchers. Over the course of eighteen months the Danes trained nonathletes to run a marathon. At the end of this training period, the eighteen men in the study had lost an average of five pounds of body fat. As for the nine women subjects, the Danes reported, 'no change in body composition was observed.' That same year, F. Xavier Pi-Sunyer, then director of the St. Luke’s–Roosevelt Hospital Obesity Research Center in New York, reviewed the studies on exercise and weight, and his conclusion was identical to that of the Finnish review’s eleven years later: 'Decreases, increases, and no changes in body weight and body composition have been observed,' Pi-Sunyer reported."

http://nymag.com/news/sports/38001/index3.html

Note that some people gained weight. My experience has always been that I neither gain nor lose. I've had a variety of exercise routines over the years, aerobic and anaerobic, at all different weights, slim to obese. Never saw my weight rise or fall as a result of exercise.

The only thing I haven't tried is an exercise program along with a low-carb diet.

I'm keeping an open, but highly sceptical, mind on the subject.

There is a bunch of stuff in basic physiology about this. Yes, exercise affects hormones. We know that and have measured it in humans.

Exercise affects insulin, cortisol, epinephrine, norepinephrine, glucagon. I did a Google textbook search and here's the sort of thing you can read in exercise physiology textbooks.

http://tiny.cc/4lKjG

I said "affect fat stores." It could make things better or worse depending on the hormone situation. Excess stress can make fat stores fatter, and that includes stressful exercise on top of a stressful life.

There is a neat interview with Phinney (who studied low carb and endurance exercise) where he thinks that the failure of high-stress exercise to help with fat loss in some people, is because of the accumulated effect of inflammation and stress (excessively stressful exercise is also inflammatory).

Oh sorry, I thought you were looking to learn about the effect of exercise on hormones.

Yes, Taubes is saying, the studies don't support our crude assumption. And then just like the diet studies, he shows how poor many exercise studies are.

But, decent studies COULD illuminate what's going on still, and tell us what kind of exercise, for what metabolic states, results in predictable fat loss. It just takes real science not junk science.

If you have read a bunch on how eating affects hormones, you really might enjoy reading how exercise affects hormones. Some of the interactions are actually agreed-upon and not "everyone has a book to sell."

I was talking recently on my journal about something.

At one point (couple years ago I think it was), during that era I happened to be tracking my calories (etc) in immense detail, and in a month ~ ~1200 (<30 carbs) lost 1# that vanished the next day. I blogged about it at the time because it seemed so insane given my weight. I raised cal to ~2200 and started losing. Yet recently on around 2200 nothing happened, but now that I've been ~1100-1600 (<50 carbs) I am losing weight again.

Now why would I NOT lose it on that at one point and lose it now?
Is it really 20 carbs of difference?
Might it be a slight shift in WHAT I was eating?
Might we have a more inflammatory response to some things at one time than another?
If we're dieting while the pollen is high does it matter? (yes I'm serious, if that is causing inflammation for some people.)
Might the passage of time/homeostasis from my previous weight loss matter?

I was saying it's not just different for every person but even for the same person at different times. No wonder it's so bloody hard to figure out!

PJ

I found fasting gives many of the benefits of exercising and some animal studies indicate this. I also weight-lift and I find fasting increases results, or hormones-- it's an anabolic process going on.

Right now I'm working fulltime, taking care of a home and a family, commuting two hours a day, and trying to finish up my J.D. I just don't have the time to read every book mentioned in this forum.



I work in a library - a law library. We have a small collection of popular books, New York Times best sellers. If I were to try to read only the diet and exercise books we have in our small collection, I would have to devote all my free time to it. And I wouldn't be any wiser in the end, because the books contradict one another.

From where I sit everyone does have a book to sell. I think it feels that way to most Americans since we're bombarded daily with contradictory health information. Even on this forum I read contradictory advice daily - increase your carbs! decrease your carbs! exercise! stay in bed! And everyone's got an "expert" and a lot of scientific-sounding language to back them up.

I have to go back to my own personal experience. I'm going to be 48 next month. I've had exercise programs over the years - starting with the 20 Minute Workout when I was about 15 to a weight-lifting program that I stopped several years ago. I've never once seen my weight go either go or down due to exercise.