Excersize doesn't burn fat!?!?

dykask

Okay there is some serious misinformation going on in this thread. Multiple people are claiming that muscles don't metabolize fat and that isn't really true. In fact there is no way people could seriously workout if it were for energy from fat.

Muscles directly use ATP but there are 3 sources of ATP for muscles:

1) Direct phosphorylation - basically uses up ATP that is already in the muscles. There is typically enough ATP in rested muscles to power it for a few seconds. Think 100m (100 yard) dash.

2) Anaerobic pathway - meaning it doesn't need oxygen. This uses glucose from blood or from breaking down glycogen which is stored locally. Glycolysis produces a net gain of ATP molecules and Pyruvic acide. Lactic acid is also produced. That is the stuff that makes you feel like your muscles are burning. This is still short term energy. Think 400m or 440 yard dash.

3) Aerobic pathway - requires oxygen and the person is breathing hard. This is for just about any use of the muscles past a minute. (Most people execerise more than a minute.) The mitochondria in the muscles cells use the Pyuvic acid from glycolysis, Fatty acids and Amino acids to produce about 16 times as much ATP. The waste products are carbon dioxide and water, it is actually a pretty clean process at this point. The waste products don't cause the muscle burn that Lactic acid causes.

So where to the fatty acids come from? Lipolysis of triglycerides which breaks them down into 3 Fatty acid changes and glycerol. Glycerol can is used in the same pathways as glucose and the liver can also convert it to glucose. There is only so much of fatty acids and triglycerides in the fat. The liver uses lipolysis to break down stored fat into the fatty acids and glycerol which are released into the blood stream. So in short when exercising for more that a brief time, one is burning fat. If fatty acids aren't available, one runs out of fuel very quickly.

However the fact that fat is being used has little to do with weight gain or loss. That depends on a lot of other factor but largely how much food is being consumed. It is possible on a daily basis to store more fat than the amount of fat used by lipolysis.

AnvilHead

dykask wrote: »

...However the fact that fat is being used has little to do with weight gain or loss. That depends on a lot of other factor but largely how much food is being consumed. It is possible on a daily basis to store more fat than the amount of fat used by lipolysis.

if one is in a caloric surplus, that is correct.

Aaron_K123

It's a play with words OP. It is true that the only thing that can make you lose weight is a caloric deficit and therefore one could say that exercise isn't the cause of weightloss and you can exercise all you want and still not lose weight. Both of those statements are technically true.

But of course exercise burns calories which can help you establish a caloric deficit in a way that enables your weightloss.

Don't over think it.

Christine_72

OP you need to read between the lines on this one, don't take this article at face value..

YaGirlMaddi

Exercise *****

lemurcat12

I thought I posted in this thread -- was there another similar one you started, OP?

shadowfax_c11

Personal experience.

My current average daily TDEE (based on Fitbit Charge HR readings) is 3500-4000 calories for a work day or work plus aikido day. At this activity level I was not losing weight because I was eating as much as I burned, sometimes more, rarely less. I was eating the same high calories even on rest days which for me can be as low as 1500 calories TDEE.

When I started keeping track of the calories I was eating and making sure they were less than my TDEE I started losing weight.

It is really easy to out eat any exercise program.

OTOH exercise does give an extra burn to either increase the deficit or the calorie allowance you can manutain and still lose. It improves cardiovascular health, can improve mood and self esteem and help to alleviate depression and can even be fun.

Christine_72

shadowfax_c11 wrote: »

Personal experience.

My current average daily TDEE (based on Fitbit Charge HR readings) is 3500-4000 calories for a work day or work plus aikido day. At this activity level I was not losing weight because I was eating as much as I burned, sometimes more, rarely less. I was eating the same high calories even on rest days which for me can be as low as 1500 calories TDEE.

When I started keeping track of the calories I was eating and making sure they were less than my TDEE I started losing weight.

It is really easy to out eat any exercise program.

OTOH exercise does give an extra burn to either increase the deficit or the calorie allowance you can manutain and still lose. It improves cardiovascular health, can improve mood and self esteem and help to alleviate depression and can even be fun.

@shadowfax_c11 Do you find your fitbit to be accurate? Say you burned 3500 everyday, could you confidentally eat 3000 calories and lose 1lb a week?

SusanMFindlay

I haven't read that article, but have read similar ones. The basic premise is that exercise alone is unlikely to result in weightloss for the average person (who does not count calories). The reasons being:

1. When most people exercise, it makes them hungrier and they often offset some or all of the calories burned by increasing the "calories in" half of the equation.
2. Many people treat exercise as a punishment that deserves a reward afterward, and the reward (frequently food or a high-calorie drink) offets some or all of the calories burned.
3. If you're not careful, your very efficient body lowers your NEAT (non exercise activity thermogenesis - the calories you burn by fidgeting, etc.) to compensate.

So, if you count calories, only eat back some of the calories burned and don't "reward" yourself with empty calories, exercise will probably help - but that's not the average person that these articles are describing.

All they're saying is that to lose weight, you have to watch what you're eating too. Not that the exercise part is bad.

MaybeLed

miss_brown1989 wrote: »

Okay so I found a random article that claims excersize doesn't help you lose weight at all. And only cutting calories does. This bugged me a lot so I researched it and found about 40 articles claiming the same thing. Here's one of the links:
https://www.theguardian.com/society/2015/apr/22/obesity-owes-more-to-bad-diet-than-lack-of-exercise-say-doctors

What do you guys say I'm so confused. They say that you get lots of benefits but no weight loss.

I didn't think it was possible that sweating your butt off working out for an hour a day does nothing for weight loss??

Obviously exercise has benefits for health and wellbeing. The theme of the article appears to be critical of food and drinks manufacturers encouraging people to overindulge by saying 'exercise it off'. There is a cardiologist saying (what many in the forum said) about people being bad at judging how much CO are influenced by exercise, and 'you cannot outrun a bad diet' so encourages people to watch the CI.

Also within that article is some experts refuting the outcome of their work:

Catherine Collins, of the British Dietetic Association, said the doctors had downplayed the metabolic and physical health benefits of undertaking even moderately intense exercise and had used “incomplete evidence” to make their case. Professor Susan Jebb, professor of diet and population health at Oxford University, who also chairs the food network of the government’s Responsibility Deal, said: “The authors fail to note that weight loss programmes which combine diet and physical activity are the most successful route to weight loss in both the short (three to six months) and medium term (12 months)”.

CI and CO are important, do exercise you enjoy and be as healthy as possible for as long as possible

snowflake930

Eat less calories than you burn, that is how you lose weight.
Your choice how you arrive at weight loss. Exercise more to be able to consume more calories and still be consuming less than you burn, or eat less calories and no exercise, or very little exercise.
Exercise is important for your overall health. I don't love to exercise, or even like to, but I exercise everyday because it really makes a difference in my health.

shadowfax_c11

Christine_72 wrote: »

@shadowfax_c11 Do you find your fitbit to be accurate? Say you burned 3500 everyday, could you confidentally eat 3000 calories and lose 1lb a week?

I really can't say. My weekends are so drastically different in energy output that I can't do a 500 calorie deficit during the week because I can't eat low enough on the weekends to avoid negating most of it.

I only use my Fitbit to determine activity level and burns for my aikido workouts.

Many other MFP people who use their fitbits to determine daily calorie goal do report that they lose as expected.