All right, this is for the stalled hamster wheelers who react to their stall by lowering their calories even more and exercising harder. I've made some crude notes.

Podcast here with Dr. Phinney. He relates his surprise when they studied women and diet with/without exercise.

9'50" Question

12'55" Exercise issue is broached.

1988 study -- Demonstrated took a group of overweight women in metabolic ward, low carb, 800 calories. 6 sedentary, 6 progressive exercise. 1/2 - 2 hours of hours exercise.

The group that exercised lost slightly less fat than the sedentary group. The explanation was that the resting metabolic rate went down 15%.

Everyone fervently believes exercise raises RMR.

Twin study, 900 calories of exercise (males). 7-8% reduction in resting metabolism.

Some people have it, some don't. Similar degree of reduction in twin pairs. Widely different between twin pairs.

Those exercising more than 1 hour a day were having this issue.

Take rest days. Don't exercise every day of the week.

Too bad I didn't hear about that study in 1988. In those days I was eating ~1200 cals/day and exercising 7 days a week for a total of 10.5 hours, losing nothing but told to exercise more and eat less, so I cut back to 1000-1100 and actually gained weight and was exhausted all the time. Of course I was accused of lying about what I was eating.

Maybe that helps explain what I posted here, where hunter-gatherers were proven to not burn any more calories than sedentary Westerners despite higher levels of activity.

Thanks for this information. Explains lots

bunk. LOL.

I came across this in Phinney's book too. I finally thought to use the Kindle underscoring ability so I'll be able to find it again. Yay! I'll post it tonight (if I remember).

My theory: our bodies are just swinging the pendulum for us and trying to compensate for the increased metabolic rate while exercising. Trying to hold on to its energy stores for when they might next be needed, particularly to fuel/replenish what's needed for vigorous exercise. So perhaps the more you try to lose wt by exercising, the more the body tries to compensate to keep from losing your energy stores (fat), also building muscle to further confound your scale. On the bright side, lower metabolic rates seem to be associated with longer longevity, so while increasing exercise to lose wt might not be a totally effective strategy - it might help you live longer?!

They actually measured body fat and muscle, so it wasn't because the body was building muscle. It was because the RMR was falling by up to 15%!

Of course, low calorie dieting also slows the RMR, so this would have been in addition to that.

Phinney says something like this:

Diet for weight loss, exercise for health.

Or as I read here:

Diet = look good in clothes
Diet + exercise = look good naked!

It was an intereing podcast (at least the part I listened to) and it make perfectly good since. The more you workout the lower your resting heart rate, right? That is common knowledge I think among people that work out anyway. So if you have a lower resting heartrate, wouldn't that affect your motabalism?

Now I have to figure out how to combat that. I teach 4 zumba classes a week not to mention how much I practice.

Sheila - what I heard the podcast say that the resting metabolism was reduced for those exercising more than ~15 hours per week. Phinney's an athlete himself, and also mentions that when he ups his miles per week of bicycling in good weather, he quickly loses the 5 lbs that he gained when he reduced his miles/week in poor weather. I would think up to an hour a day would not be detrimental.

well loss is almost nada anymore. I guess I'm trying to find something to blame it on. I used to blame it on my age (nearing 50) then I used to say it was because I didn't workout. I guess I was just hoping this might be why.

Honestly I can lose, just so super slow that I get overly impatient

It depends on the intensity of that hour, and how acclimated the person is to it. Very intense and not acclimated = more like war & famine, and the metabolism dials down.

I keep pointing people to Tom Venuto on this topic. he also talks about how deadly it is to restrict calories and increase the hard cardio.

The deal with daily athletes (4 Zumbas a week, plus practice!) is the challenge to eat enough so the body doesn't think it's famine, and to rest enough so the body doesn't think it's war. if I was doing that much Zumba I would make practice and teaching the same days, just so I could have rest days that were no more intense than a little walking, mobility, and stretching.

Perhaps. I'm just passing on what Phinney had to say, and I don't remember him mentioning intensity of exercise; as I recall he focused more on duration. It makes sense that both would matter.

question: am i understanding correctly that the study of women, they were on 800 cal diets? and then exercise was added on top of it? seems to me there could be an issue with calories being so low and not high enough to support exercise. that's not a valid experiment to measure exercise effect, with a caloric intake that is so low already. the body lowers metabolism to try to survive.