The Skeptics Guide to the Universe Forum

Quote from: jt512 on September 26, 2023, 08:46:56 PM

Quote from: bachfiend on September 26, 2023, 05:05:30 PM

Quote from: jt512 on September 26, 2023, 05:26:52 AM

Quote from: bachfiend on September 26, 2023, 02:51:16 AM

Quote from: jt512 on September 25, 2023, 11:34:35 PM

Quote from: bachfiend on September 25, 2023, 10:27:54 PMAs you become fitter, by exercising daily and after a period, your daily energy expenditure falls back to what it was when you were sedentary because you're expending less energy when you're resting or doing light everyday activities cancelling out the energy expended exercising.

Let's see the metabolic studies that show that, or is that just your hypothesis.

BTW, for you personally, since you do around 1000 kcal/day of exercise, you would have to somehow save 1000 kcal/day somewhere else. Even if you just spent the rest of the day in bed, you wouldn't be able to reduce your energy expenditure that much.

The metabolic studies have already been done, indirectly, using the gold standard doubly labelled water method comparing sedentary and active populations, even of the same ethnic group, so it's not just comparing Americans to San tribes.

Citations needed.

QuoteAnd we also know that training results in less exertion, and less energy expenditure, for the same, or even greate amount of, work performed.

From my heart rate monitor, yesterday I was expending less than 50 kcals per hour.  22 hours time 50 kcals per hour equals 1100 kcals.  Plus the 900 kcals I expended in the gym that equals 2000 kcals, less than the 2252 kcals measured with the heart rate monitor.

I have no idea what you're saying here. Do you mean that had you not gone to the gym, your total 24-hour energy expenditure would have been 24*50=1200 kcal? That would be ridiculous.

One of the options I offered when I reported my energy expenditure using the heart rate monitor (the first time before I'd gone to the gym I'd said that after 11 hours my energy expenditure at rest was coming out at less than 50 kcals per hour) was that heart rate monitors are very inaccurate at estimating energy expenditure, let alone daily energy expenditure, yet all the research on the role of exercise in weight loss relies on heart rate monitors relies on heart rate monitors , and the estimates are regarded as accurate.

Energy expenditures increase nearly linearly with heart rate. The slope of this line is remarkably consistent from person to person. However, the intercept (your resting heart rate) varies greatly from person to person. However, if you know your RMR and your resting heart rate, you can rely on your heart rate to accurately predict your energy expenditures for any heart rate.

Furthermore, because the slope is consistent from person to person, HR can be used to accurately calculate the average energy expenditure of a group. This is because the individual differences in the intercept will average out. For this reason, HR can be used in clinical trials to determine the effect of an intervention on exercise expenditure. This is because the quantities of interest are the group means.

QuoteIt shouldn't be controversial that you exercise for fitness.

It's not "controversial" to me. It's wrong.

QuoteThe authors of the study I cited at the beginning of this thread (people who exercise in the morning are thinner than people who exercise in the evening, who in turn are thinner than people who exercise at midday - I exercise at midday) offered a number of hypotheses to explain their data, one of which was that people who exercise in the morning have a healthier eating pattern, so it comes back to diet, not exercise.  Another one of their hypotheses was that people who exercise in the morning are burning stored fat not recently ingested carbohydrates - which to me seems like nonsense; a calorie is a calorie.

I have to give credit to the authors for admitting that they don't know what the direction of cause and effect is between the independent and dependent variables in their study, or even if they are causally connected at all. Usually, it's more like, "As predicted,..." or "Consistent with our hypothesis...."

References for your claim that heart rate monitors will accurately predict energy expenditure?  And how is the energy expenditure measured?  In this recent review, a particular heart rate monitor showed underestimation of heart rate by 3 bpm, steps by 3 pm, and and energy expenditure by 3 kcals per minute, which varied according to age and activity:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9047731/

The reviewers thought that an underestimation of 3 kcals per minute is significant.  And how was the energy expenditure being measured as a control?  If the control measurement of energy expenditure isn't being measured accurately, then it's irrelevant whether the heart rate monitors' algorithm gives an estimate of energy expenditure close to the control measurements even if they're precise.

So you think it's wrong that people exercise for fitness.  You think people exercise for unfitness?

The authors of the study were looking to see if there was a difference in weight depending on when people exercise.  It was their hypothesis that there is, and their data provided evidence that their hypothesis is true to the extent that it wasn't disproved.  They went onto proposing hypotheses to explain their data, and stated that further studies were necessary to test the various hypotheses.  The way science should work.

Here's another paper:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4005766/

In the discussion, it's stated that 67% of subjects have significant errors in estimations of energy expenditure, which may amount to under- and overestimates of energy expenditure by as much as 500 kcal per day.

If you're overestimating your energy expenditure by 500 kcals per day, and matching your caloric intake to that then you're going to get overweight or obese pretty quickly.

After two and a half months on 10 mg of Rosuvastatin and 10 mg of Ezetimibe I got a blood test yesterday. (I also take blood pressure and thyroid medications.) The previous test was after I'd been on the Rosuvastatin, so the Ezetimibe is the new one now.

My total cholesterol came down from 170 to 124; my LDL came down from 106 to 67; My HDL went from 55 to 50; my triglycerides wen down from 43 to 37; and my ratio Total/HDL went down from 3.09 to 2.48. My AST and ALT (which are tested to look for liver damage from taking statins) are up slightly, but are still in the lower half of the normal range. In fact, all my numbers on the test are normal.

(HDL going down is bad, but in the context of everything going down I think it's fine.)

My cardiologist wanted to get my cholesterol, and especially my LDL, down significantly from what they were. The numbers before were normal for a normal person, but because of my sky-high coronary calcium (1,375) he wanted my lipids much lower. I think he'll be happy with these numbers. I see him on Friday.

("Normal" coronary calcium is zero. Average for men of my age is 200. 300 is considered high enough to warrant aggressive treatment with statins.)

Quote from: CarbShark on September 26, 2023, 05:44:06 AM

Quote from: jt512 on September 25, 2023, 07:48:41 PMSo, to recap. We are now all in agreement that if you are in energy balance, then (1) increasing exercise increases your total energy expenditures, (2) doing that while maintaining your current diet leads to negative energy balance, (3) and that in turn loses to weight loss.

On paper, yes.

Are we all agreed then that in clinical trials where exercise is used by itself as a weight loss intervention it has not found to be effective...

No. When exercise is sufficient in quantity and closely supervised, so that compliance is assured, clinical trials have shown that exercise alone is effective in producing weight loss. Look at these results, for example:



These are results from a 10-month clinical trial in which untrained overweight and obese male and female subjects were randomized either to control (no exercise) or to 5-day-a-week aerobic training, that was progressively increased to either 400 kcal or 600 kcal per session. No dietary advice was provided. All exercise sessions were supervised by study personnel to ensure that the target exercise expenditures were achieved at every session.

Both exercise groups lost body weight and fat and gained lean body mass. Those in the 600-kcal group, naturally, lost more weight and fat than those in the 400-kcal group. There were no significant difference between sexes.

BMR was measured throughout the 10-month study and did not decrease, despite the beliefs of bachfiend, which disagree with the entire literature on the subject.

Except for having to come into the lab for an hour or so 5 days a week, subjects maintained their normal lifestyles. Thus, subjects lost weight despite whatever compensatory mechanisms you, bachfiend, and the other exercise deniers think occurs.

Quote...and where exercise has been used with a weight loss diet it has not been found to be significantly more effective than the weight loss diet by itself?

No, I haven't seen that. What I have seen is that the combination of diet and exercise produces greater effects than either one alone, as almost must be the case. Weight loss is proportional to energy deficit.

I would not trust a heart-rate monitor to tell me how many calories I'd burned. It sounds to me like a gimmick to sell heart-rate monitors. Sure, you burn more calories with physical activity, but there are too many other factors that differ among individuals. The treadmill I had in Spokane, and the elliptical I have here, as well as the machines I've used in gyms, tell me a number of calories, but it's a gimmick. The only reliable, objective, information they can give you is your elapsed time on the machine. Also cadence and resistance level, but those are subjective to the specific machine.

Quote from: bachfiend on September 26, 2023, 05:05:30 PM

Quote from: jt512 on September 26, 2023, 05:26:52 AM

Quote from: bachfiend on September 26, 2023, 02:51:16 AM

Quote from: jt512 on September 25, 2023, 11:34:35 PM

Quote from: bachfiend on September 25, 2023, 10:27:54 PMAs you become fitter, by exercising daily and after a period, your daily energy expenditure falls back to what it was when you were sedentary because you're expending less energy when you're resting or doing light everyday activities cancelling out the energy expended exercising.

Let's see the metabolic studies that show that, or is that just your hypothesis.

BTW, for you personally, since you do around 1000 kcal/day of exercise, you would have to somehow save 1000 kcal/day somewhere else. Even if you just spent the rest of the day in bed, you wouldn't be able to reduce your energy expenditure that much.

The metabolic studies have already been done, indirectly, using the gold standard doubly labelled water method comparing sedentary and active populations, even of the same ethnic group, so it's not just comparing Americans to San tribes.

Citations needed.

QuoteAnd we also know that training results in less exertion, and less energy expenditure, for the same, or even greate amount of, work performed.

From my heart rate monitor, yesterday I was expending less than 50 kcals per hour.  22 hours time 50 kcals per hour equals 1100 kcals.  Plus the 900 kcals I expended in the gym that equals 2000 kcals, less than the 2252 kcals measured with the heart rate monitor.

I have no idea what you're saying here. Do you mean that had you not gone to the gym, your total 24-hour energy expenditure would have been 24*50=1200 kcal? That would be ridiculous.

One of the options I offered when I reported my energy expenditure using the heart rate monitor (the first time before I'd gone to the gym I'd said that after 11 hours my energy expenditure at rest was coming out at less than 50 kcals per hour) was that heart rate monitors are very inaccurate at estimating energy expenditure, let alone daily energy expenditure, yet all the research on the role of exercise in weight loss relies on heart rate monitors relies on heart rate monitors , and the estimates are regarded as accurate.

Energy expenditures increase nearly linearly with heart rate. The slope of this line is remarkably consistent from person to person. However, the intercept (your resting heart rate) varies greatly from person to person. However, if you know your RMR and your resting heart rate, you can rely on your heart rate to accurately predict your energy expenditures for any heart rate.

Furthermore, because the slope is consistent from person to person, HR can be used to accurately calculate the average energy expenditure of a group. This is because the individual differences in the intercept will average out. For this reason, HR can be used in clinical trials to determine the effect of an intervention on exercise expenditure. This is because the quantities of interest are the group means.

QuoteIt shouldn't be controversial that you exercise for fitness.

It's not "controversial" to me. It's wrong.

QuoteThe authors of the study I cited at the beginning of this thread (people who exercise in the morning are thinner than people who exercise in the evening, who in turn are thinner than people who exercise at midday - I exercise at midday) offered a number of hypotheses to explain their data, one of which was that people who exercise in the morning have a healthier eating pattern, so it comes back to diet, not exercise.  Another one of their hypotheses was that people who exercise in the morning are burning stored fat not recently ingested carbohydrates - which to me seems like nonsense; a calorie is a calorie.

I have to give credit to the authors for admitting that they don't know what the direction of cause and effect is between the independent and dependent variables in their study, or even if they are causally connected at all. Usually, it's more like, "As predicted,..." or "Consistent with our hypothesis...."

Herding sheep is near impossible without a good sheep dog. With a good sheep dog it's a piece of cake.

China's coal-based energy production as a percentage of its total energy production will decline, but its total energy production is rising so fast that the lower percentage can easily be a larger actual output. The world's CO2 output is rising, and we don't even know where the tipping point is. Melting permafrost is releasing methane into the air; melting ice is lowering the Earth's albedo; we're burning coal and oil and natural gas as fast as we can claw them out of the ground; and the nations of the world are more concerned with fucking each other over than with preserving the planet we have to share. Here at home, half the population and half, or more than half, the legislators, don't even believe there's a problem, and none of the countries with the political, economic, or military power to actually influence world affairs gives a shit about anything but their own hegemony. We have the technology to limit the damage, but the people in power just want to amass more power and more money.

Quote from: Quetzalcoatl on September 26, 2023, 04:59:53 PM

Quote from: RickyDMMont2ya on September 12, 2023, 09:08:11 PM

Quote from: Desert Fox on August 29, 2023, 02:05:53 PMI think we need to plan for a worst case situation

Worst case is a planet that is not able to be inhabited by humans. What kind of planning are you proposing for that?

Is that really a possibility? I would think that even with an extremely warmer climate, humans could still live in the far north and far south. And maybe in other regions if they stayed inside buildings with AC most of the time. Come to think of it, maybe that would be necessary in the polar regions as well.

Of course, that would mean a radically different world than we have today and such a would could support a far smaller population than the one we currently have. It would be a very bleak world, but it wouldn't mean human extinction.

Right. Worst case scenario is probably that the planet could no longer support billions of humans.

Bleak, yes, but human extinction is not likely.