EGreen

Over the past two weeks I had been huddled over the books nearly continuously. Riding and all of my other usual physical activities were deferred.

However, I kept my habit of daily weigh-ins. Towards the end, I found I lost weight though my food intake remained the same. I'm not talking a great amount of weight - just nearing the low side of my range - ordinarily experienced after 300+ mile weeks + other high output endeavors.

I am guessing at this and invite others to do so as well.

Has the stress of finals increased my metabolic requirements to the extent that riding and vigorous physical activity does? Have I lost muscle during this time? Might it be a natural trend independent of my efforts or cognition? Any other possible reasons for this? (other than hyperpyrexic, endocrine, or wasting diseases that I do not have)

Tabagas_Ru

This reminds me of an interview that I saw.

It was with a guy who has a new diet book out who thinks exercise is counterproductive for weight loss. He said that since exercise makes you hungry you should not exercise if you are trying to loose weight.

I wish I remember the name of the guy it was quite entertaining.

I hear ya on the studying for finals thing, it will do strange things to your body.

ModoVincere

Would be real easy to lose weight by not exercising for me. I could eat all the carbs in sight, not take the medication, let my blood sugar rise up over 300mg/dl, and the weight will drop like a rock.
Of course there would be some other complications along the way....but what the heck.

BloomBikeShop

I've had the same thing happen. The thing is, it only works like that sometimes. Other times I gain weight... so I'm not sure what it actually is.

One thing I have realized though is that when I'm taking time off and thinking I'm eating the same amount, I'm actually eating quite a bit less. Not to mention all the on-bike calories I'm missing.

This is a fun guessing game

webist

I find it generally impossible to explain weight fluctuations from day to day. Even though I weigh daily, I really only pay attention to trends visible over several days.

kuan

Your brain is using calories?

EGreen

That's not as silly as it sounds, I think. Brain on overdrive must have an effect on metabolic rate (as emotional stress, worrying does)... this being the sole factor is unlikely though ... I think.

SSP

Our large brains burn a lot of calories.

I assume that when we're "amped up" mentally, we're burning somewhat more.

ModoVincere

No links, but I remember a stat from somewhere, that said a person studying and committing a lot to memory, their brain will produce use as much energy as a 100 watt light bulb.

acroy

I would think you've replaced muscle with fat.

This happens to me a lot. You can only tell for sure by measuring your BMI or whatnot. But i know whne I go on vaca or get sick or whatever, I most definitley loose muslle mass & strength

ModoVincere

BMI really won't work in that situation very well. It is a measure of weight versus height, not muscle mass. In fact, using BMI on many Body Builders would classify them as morbidly obese, which they are not.
You would want to use any of a number of ways to determine your % of Body Fat, before and after to see what the change in composition was.

kuan

How fast does one lose muscle mass?

Carbonfiberboy 

I also lose weight during a layoff. I think this is temporary. Loss of blood volume, slight muscle shrinkage. I'd bet that in a month I'd start putting it back on. Similarly, after a layoff or just a period of taking it easy, when I start working out hard again I'll gain weight. So I figure it's blood volume and I think your muscles pick up some intercellular fluid or something. You can feel they've pumped up a bit after a couple of hard workouts.

It's always discouraging to see that weight gain for the first two weeks, but then it goes back the other way as the exercise volume gets back up there and the calorie burn has its effect.

MMACH 5

Ever since puberty, I've been a rather thin, almost scrawny person. I started riding two and a half years ago and have gained close to 15 pounds. During the early part of this year, I was putting in some crazy overtime at work and didn't get on my bike for six weeks. I lost seven pounds. I probably wouldn't have noticed or even stepped on a scale except that my wife pointed out that my "horse knees" had come back, (thanks Honey).

If you normally have a slight build and fast metabolism, I'm guessing this is somewhat normal.

And on a side note, after the six-week hiatus, it took me another six weeks to get my legs back "under" me again. Due to minor surgery this past September, I was off the bike for two weeks and it took two weeks to feel like I was back to full strength.
I'm 41 and since you are in school, I have to assume you are about half my age. Your bounce back time will most likely be shorter, but don't be discouraged if it feels like you are having to work harder on the bike. Stay after it and your legs will come around.

Nickel

I don't know how much muscle mass you lose but I can't imagine it is very much in a 2 week period. You don't say how much weight you have lost but I know that water can cause fluctuations up to 5 lbs or more. I imagine you are burning more glucose from studying. I don't know if this explanation is correct but here is a hypothesis. If you eat the same amount of food, but your body is wanting to burn more of the glucose since you are thinking non-stop, there will be less glucose available for your muscle glycogen stores. I think you need x number of water molecules to store 1 molecule of glycogen. If there is less glycogen being stored, there is less water, which may lead to a weight reduction.

??

Tabagas_Ru

If you are under stress and have no way to release it your weight loss could very well be because of muscle loss, as well as fat. First, you are not using that extra muscle anymore so your body sees no need to have the extra muscle around. Second, stress hormones such as cortisol act by raising blood sugar by causing glycogenolysis in the liver, as well as hepatic gluconeogenesis. Cortisol reduces amino acid use for to form proteins by decreasing transport across cell membranes, except in the liver, thereby increasing the amount of AA's for use in gluconeogenesis. Increased glucocorticoids also leads to a decrease in fat formation and increased lipolysis.

Someone also mentioned something about glycogen and water, this effect would be bigger as well because of the fact that there is not as much muscle to absorb the water and store glycogen. Relating this to cortisol, there is also less glucose uptake by cells when there is increased cortisol levels. This would also relate to your muscles not storing as much glycogen because they are not able to absorb glucose like they once did.

So you probably lost a very small amount of muscle, don't have as much water or glycogen in your system, and you may have lost some fat as well.

In the end it is probably due to many factors related to stress, and lifestyle change, not a single thing.

ChunkyB

I'll throw another vote in there for muscle loss. Typically stress results in fat gain, not fat loss. Hopefully you haven't lost too much fitness though. Good luck with finals if you're not done, and if you are, CONGRATULATIONS!!!!!!!!!!

MrCrassic 

From the way that my chemistry teacher of a long time ago explained it, when you are studying intensively, your body uses A LOT of resources to power the brain (many more than they normally do). That's why sugar is a necessity while studying; it's the most effective way to retain focus.

As far as the lack of weight loss goes, did you change your diet at all or did you remain the same? I know when I was doing 125 - 150+ mile weeks consistently, I lost a ton of weight, but when winter showed up, I reduced the amount of cals in my diet (less than 2000 daily, I think) and did light calisthenics and my weight actually continued to decrease. I don't even know where I am, but I would have to say that I gained very little, if anything.

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