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Ronin

90 minute rule

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Ronin

On Sunday I was having a chat with a friend who is also an Endo with a Ph. D. in Bio-Chemestry about "winter weight gain." This led to a long discussion about physiology and exercise that ended in an Ah-Ha moment for me.

 

She noted that when a person is engaged in aerobic exercise the effort require to result in weight loss requires at least 90 minutes of sustanined activity in the areobic zone.

 

Translating the conversation into some short items:

 

  • The first energy to go is the glycogen stored in the muscle cells themselves.
     
  • Next is the free glucose in the blood stream.
     
  • Next is the stored glycogen in the liver.
     
  • Finally, the fat cells are called upon to give up their energy for the cause of keeping the body moving.

The replenishment cycle is pretty much the same, with the muscle cells first, liver second, and fat cells last.

 

The first two souces of energy are used pretty fast - actually in minutes. The liver takes a while to empty and is the reason that the sustained effort over 90 or more minutes is required to draw down energy from the fat reserves.

 

My Ah-Ha moment was realizing that my hour of aerobic training in the winter is enough to maintain my fitness but not enough to draw on the fat reserves, and since I eat pretty much the same amount of calories per day, I gain in the winter only to have those pounds fall off in the spring.

 

I don't know if your reaction will be good news or bad but I now finally understand the mechanism and how it works. Now, if the weather will only cooperate I'll get back to my 90+ minutes of daily tandeming/bicycling and get rid of these winter pounds.

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Gordonm

That is the first time I have ever had it explained in terms I can understand. It sure makes sense. I have put on a few pounds this winter also due to less exercise and less time doing it. Should be warmer by this weekend. If the snow melts I'll be out there.

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Caravaggio

Thanks Ronin for the clear and concise explanation. I'll remember this the next time I complain about my long runs. :D

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lorilei

on the flip side...it takes only an increase in 2 min per day for a sedentary person to demonstrate cardiovascular benefits....

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Subby

  • The first energy to go is the glycogen stored in the muscle cells themselves.
     
  • Next is the free glucose in the blood stream.
     
  • Next is the stored glycogen in the liver.
     
  • Finally, the fat cells are called upon to give up their energy for the cause of keeping the body moving.

 

How would you see taking in glucose doing the exercise, fit into this list, work within this system? Let's say 30g every 20min, which is the kind of thing an insulin dependent _might_ need to do to keep from hypoglycemia with a moderate forms of exercise (due to basal insulin becoming so much more effective, by the short term metabolic change). Would virtually any carbs halt the progression of "the list"? Or would that be likely still progressing along in the background, given some kind of threshold of not taking in too many carbs?

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fgummett

It is a good explanation of how the body uses various energy sources -- including fatty acids -- but as you mention it also follows the same pattern for replenishment AKA "eating".

 

Exercise has many health benefits but so far as I am concerned it is a non-starter for weight-loss... increased physical activity leads to increased appetite.

 

Unless you can become more active, while at the same time starving yourself without your body slowing down its cell activity (which it will do if you take in less energy) you can only hope to make minor, short-term changes to your weight.

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Mich

Geez, and I thought it was ancient survival genes trying to get me through the long period without fresh food. :T

 

Thanks Ronin, it makes a lot of sense. Darn.

 

Mich

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Russell A.

So much for thinking that 30 minutes on the bike 3 times a week was helping me loose weight.

 

At least I am making my heart stronger! (I Hope)

 

Russell

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jps

Well this just bites. I've completely altered my lifestyle, cut more things than just food, so I can be healthier. And I just don't have the time for 90 minutes of cardio per session.

 

I typically hit the gym for an hour to an hour and 15 minutes per day, five to six days a week. I typically spend 45 minutes on cardio and 30 minutes with strength training. I wish there were more hours in the day so I could, but I've trimmed the fat, so to speak, as much as I possibly could.

 

It's wake at 6, work from 7 to 4, gym from 430 to 545, second job from 630 to 1030 pm, shower and hit bed by midnight. I'm cool with 6 hrs of sleep per day, but I don't want to start taking time away from that.

 

This sucks.

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Caravaggio
Well this just bites. I've completely altered my lifestyle, cut more things than just food, so I can be healthier. And I just don't have the time for 90 minutes of cardio per session.

 

I typically hit the gym for an hour to an hour and 15 minutes per day, five to six days a week. I typically spend 45 minutes on cardio and 30 minutes with strength training. I wish there were more hours in the day so I could, but I've trimmed the fat, so to speak, as much as I possibly could.

 

It's wake at 6, work from 7 to 4, gym from 430 to 545, second job from 630 to 1030 pm, shower and hit bed by midnight. I'm cool with 6 hrs of sleep per day, but I don't want to start taking time away from that.

 

This sucks.

 

 

I wouldn't worry about exercising less than 90 min. of cardio per session. If you can't do 90 min., you can't do 90 min. 75 min. of almost daily exercise is more than what people are even prepared to do, especially given that you have 2 jobs. You have also changed your diet. The combination of a healthy diet and regular exercise will give you a healthier body and will help you lose weight or maintain your weight.

 

You can also think of it this way: exercising less than 90 min. may not hit your fat stores but you are likely not storing additional fat! :)

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lorilei

I agree that readers to this thread should still realize the benefits of any exercise...that is why i posted the info about the 2 min benefits to the sedentary...while it may or may not take 90 min to burn fat, this does not mean that someone who is exercising less does not have any cardiovascular, metabolic, or mental benefits from whatever exercise they can fit in...

 

i think the op's intent was to provide an answer/explanation for a common ccurrence and not to downplay the benefits of any exercise...

 

....so i guess we all should "keep on keeping on" and step it up if it fits your personal lifestyle and your goals...

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fgummett

Good point Lori... and let's not downplay the simple act of getting up from your desk and going for a walk... or taking the stairs... or parking at the far end of the car park ;)

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fgummett

Although I guess I'd have to caution against sprints or any other high stress exercise for someone carrying excess weight... consider the strain on the joints and heart for example.

 

Again not suggesting we don't exercise... just advising moderation and balance. ;)

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foxl
Although I guess I'd have to caution against sprints or any other high stress exercise for someone carrying excess weight... consider the strain on the joints and heart for example.

 

Again not suggesting we don't exercise... just advising moderation and balance. ;)

 

Clearly! But ... carefully-controlled sprints (using a heart rate monitor, staying within age-determined limits) and recumbent bike sprinting can be both safe and useful, to a somewhat fat geezeress like me!

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jps

Thanks guys. I read it last night and it got me down for a second or two. No offense intended towards the OP. It's just that I'm the type of guy that is rarely satisfied and I rarely feel proud of my "accomplishments". I wouldn't even walk after my Masters because it's what I fully expected all along, so I didn't consider it an accomplishment. When my baseball team won the state title, I celebrated for that night but I went right back to work the very next day. Sad perhaps, but it's just the way I am. I usually don't thrive from validation from others, only validation from myself which is hard to come by - though, I will admit, hearing the "Wow's" daily because of my appearance change and demonstrated discipline does give some motivation.

 

But I will be quite honest here - I am, for a change, very proud of what I have accomplished in the past 8 months. That is a rarity for me. I love the feeling.

 

I kinda took the original post as I'm not doing nearly enough and I know I've been dedicated to this "cause". I've sacrificed alot, as you all have, to make this work. I'm dedicated to take what is, for some people, one of the worst, life altering situations and turn it into an absolute positive in my own life.

 

Even though I haven't hit that magical 90 minutes of cardio and probably never will, I know I'm still dropping weight. Not as quickly as I'd like. I expect some of that has to do with strength training adding weight. But the fat is definitely coming off too. The B-cup is now flat, the beer belly is nearly flattened and the abs are starting to show some definition. Heavy definition in the arms (they aren't huge, but they are defined) with no flab at all. So I'm happy with things as they are and I'll continue doing the same things.

 

I was probably a bit grouchy last night and admittedly, I was oversensitive to the original post. Funny, it was coming off the best workout I've had yet.

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lorilei

magic happens at what ever number you do that is beyond the duration and the intensity of what you did before...what do you call the reverse of magic when you stop what you were doing and realize how much you had actually accomplished because you lose all your gains??

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jps

Who knows, the mileage may vary with the amount of exercise anyway. There isn't really going to be some magical number that fits everybody, just like there's not a magic number for the weight you should be based on your height, how much two cups of oatmeal is going to affect you, etc.

 

Today at 1:45, I did a ketodiatix - ketones were +/-, very weak, but present. At 2:15 pm, I had lunch. Three ounces of ham, about a cup of asparagus, 1/2 cup of buttered carrots, and 16 oz bottle of water...Premeal BG 84. Hit the gym at 4 pm, preworkout BG 86. Only had time for 30 minutes of cardio, nothing else. Got back from the workout at 4:40. Glucose 87. Ketodiastix 3-4+ Ketones.

 

I'm not claiming a solitary instance as empirical proof of anything of course, but I'm obviously burning some fat. The lunch was very typical (low carb), I didn't starve myself.

 

Something made me start burning fat.

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jps

After a couple more weeks of doing between 30-45 minutes of cardio instead of the suggested 90 minutes, I can attest that for me, I'm definitely burning fat. Ketones are still showing in the urine and I had to go shopping for clothes again today. Weight loss over the past two weeks isn't huge, but not bad, 3.5 lbs.

 

I wish I had the time to do 90 minutes per day, I'd get to my ideal weight (whatever that may be) much more quickly. But I'm not so sure with the theory that 90 minutes of sustained aerobic exercise is required for significant burning of fat.

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lorilei

that is great jps...you might even want to start a new thread to inspire others! Small changes can make signifcant differences in the long run..

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LittleMaxi

Myself and quite a few number of people that I know, have had numerous body fat % tests, all of us limit our cardio to less than an hour, and every last one of us has reduced our body fat %, so if anyone is getting the idea that you need to do atleast 90 minutes of cardio to properly burn fat, they are sadly mistaken... JPS, you keep on doing what your doing, you ask why ? Because its working ! I think that this post had great intentions, but I believe it has possibly discouraged some people from making the effort to do the cardio they need everyday...

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Eddy
Not to mention recent research into the effect of sprints on insulin resistance ...

 

Thanks for pointing that out. I must share with non-forum T2 friends. :)

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