Why does my body only lose weight when I take a break from exercising?

May 21, 2007 7:46 PM

Why does my body only lose weight when I take a break from exercising? I exercise three weeks, take a week off and on the week off I lose weight. Why?

My typical workout routine consists of 30 minutes of cardio seven days a week, weight lifting three times a week, sauna three times a week and swimming once a week. The cardio is 30 minutes ramping from 3% grade to 15% grade. 3.0 through 4.0 on the speed. Weight lifting is on cybex equipment with 12 reps at the max weight I can lift with major burning on the 12th rep. Sauna in 170 - 200 degree dry sauna for 20 minutes. Swimming 1/2 mile and sprints in the pool one night a week.

What I have noticed in the last four months is that I lose no weight during the three weeks I exercise. I take a week off to let my body heal up, and only in this week do I lose weight. I've lost 90 pounds since September 06 and still have more to lose.

My diet is low carb with not an excessive amount of calories. I eat less than 20 carbs a day and I do not enter ketosis that often. Maybe once or twice a month regardless of whether I am exercising or not.

My water intake is prodigious.

I discussed this with my doctor and he couldn't really explain it. He did put me on a small diuretic (12.5 mg Hyrdochlorothiazide once a day) to ensure that I wasn't retaining water.

So, I am hoping someone on here can explain it, tell me they experience the same thing or point me in the right direction.

posted by zymurgy to health & fitness (23 answers total)

A wild guess: You drink a lot more during exercise, probably more than you need to. The weight you are losing during the off week is just water weight. Most people, myself included, don't track water intake all that much and usually over do it when exercising since that is the safer option.

Do you have a body fat scale? While they aren't super accurate they can help you keep track of what's really going on.
posted by chairface at 7:58 PM on May 21, 2007

Even if the only carbs you consumed were from fruits and vegetables, you would be hard pressed to limit yourself to 20. Are you certain that's correct?
posted by peep at 8:01 PM on May 21, 2007

Another wild guess -- you are losing muscle mass, which is more dense.
posted by Comrade_robot at 8:04 PM on May 21, 2007

Chairface ... if I'm only losing water weight I would think it'd come back when I start exercising again. It doesn't.

No body fat scale. How do those work?

Peep ... yes, I keep track of everything I eat with the software Nutribase. My significant carbs come from Brocolli and Cauliflower. Everything else is protein/fat based. My blood work is whistle clean and much better than it was before.
posted by zymurgy at 8:04 PM on May 21, 2007

Comrade: Thanks for the answer. Again, the weight stays off and I can lift more than I did before the break. Every three weeks I bump up the weight I lift 5 pounds. Does that make sense? Do you make extraneous muscle that the body discards when it thinks it doesn't need it?
posted by zymurgy at 8:06 PM on May 21, 2007

Is there a reason you're exercising 7 days a week? Most trainers I know recommend at least 1 rest day per week. Maybe your body is tired from exercising too much during the 3 weeks on. Instead of 3 weeks on, 1 week off, maybe try 3 days on, 1 day off for a few weeks and see if that makes your weight loss a little more steady.
posted by decathecting at 8:16 PM on May 21, 2007

No body fat scale. How do those work?

Four metal plates on the bathroom scale, two for each foot. You input your height, age, and gender, the scale adds your weight to that dataset, and measures the electrical resistance between your feet. Muscle and fat have different resistance.
Scales gives you a bodyfat %, and a water-content %

(Four plates are used so the resistance at the point of contact can be subtracted from the reading)

There are also handheld versions, basically just meaning you have to manually enter your weight, and the reading is of your arms and torso, instead of your legs and torso.
posted by -harlequin- at 8:22 PM on May 21, 2007

Do you make extraneous muscle that the body discards when it thinks it doesn't need it?

Yes. The body likes to get rid of excess muscle. It is expensive to maintain and not very energy dense compared to fat. So, if the body does not think it absolutely needs the muscle it will shed it, which is why low-calorie diets with no weight bearing exercise tend to leave the dieter still flabby and with a much-reduced metabolism.
However, you are lifting a reasonable amount and eating plenty of protein, so it's doubtful you're losing a lot of muscle mass. My only guess as to this weight fluctation would be the muscles releasing stored glycogen which also causes a dramatic loss of water along with it. When you're working out intensely your muscles hold on to a lot of glycogen and water. I know that I can lose a few pounds just by not working out for a week thanks to glycogen and water loss.
Are you sure that you *only* lose weight during this off week, or is the weight loss just much more dramatic then? Do you regain any weight once you go back to exercising? Do you eat any differently on your off week?
posted by ch1x0r at 8:23 PM on May 21, 2007

I find when I exercise I don't lose weight as my body is building more muscle (and losing some fat). When I take a break, I still lose fat, but no muscle building is needed, so the scales show relative minus difference.

When I start exercise again, I can perform better, thanks to the new muscles.

If I exercise identical, ie, don't push myself a little more, I also lose weight, presumably as it is not needing to build more muscle.

But that was just my guess.. no professional background.
posted by lundman at 8:23 PM on May 21, 2007

decathecting: Why do I work out 7 times a week? Well, I still have more weight to lose and I have guilted myself into thinking if I don't work out every day I am slacking. The cardio is the only portion that I do every day. My heart rate peaks at 150ish.

-harlequin-: thanks for the explanation. I will see if I can snag one this weekend.

ch1x0r: Fascinating. I never considered the framework of the muscle with the glycogen. During the weeks I exercise it will go down and up, but the difference is never more than a pound. On the week off I lose at least 8 pounds and usually 10. My diet remains the same regardless of whether it's an exercise week or not.

lundman: Interesting. This along the lines of what I was thinking. Again, I am not a medical doctor. My logic says that the muscle mass I've gained signals my body to keep a store of energy ready to use. When I take that week off my body realizes it doesn't need it and sheds. That's the essence of my question ... what is happening to cause it. It's good to hear you have seen something similar.
posted by zymurgy at 8:41 PM on May 21, 2007

I take a week off to let my body heal up, and only in this week do I lose weight.

I think healing is the key, zymurgy.

When people exercise as hard as you do, they actually cause inflammation in muscle tissue. With inflammation comes swelling (edema). As you heal up, that inflammation and consequent sweling resolve, and your body excretes the excess fluid that constitutes the swelling, which is water and a few waste products.

And so you lose that much weight.
posted by jamjam at 10:21 PM on May 21, 2007

If you're losing 10lbs in a week without excercising its not fat you're losing, its mostly muscle and water.
In your exercise weeks you're building muscle and losing fat, in your off weeks you're likely losing that muscle along with a lot of water.
Its not just your excercise program though - your low carb, high protein diet is dangerous and incredibly bad for your body. Low carb diets lead to a depletion of sodium in your body which your body responds to by shedding water to regain balance.
For every lb of body fat that you're losing you're losing about 4lbs of water, not to mention the muscle.
High protein is also causing you to excrete calcium and other minerals that can lead to kidney stones and osteoperosis.

Even Atkins only recommends the 20g carb intake for 2 weeks. If you are eating so few carbs then you're not getting enough fruit, veg or fibre in your diet.

Ofcourse the worst part of these fad diets is that when you've acheived your goal weight you will return to 'normal' eating habits and most people regain the weight they lost.

You've mentioned your workout and how much carbs you're eating but what you dont mention is your calorie intake. This is the *most* important part of weightloss. Burn more calories than you consume - that is the only way to successful fat loss. Doing so slowly with a calorie controlled diet that you can stick to (forever) is the only permanent way to lose weight. Low carb/high protein is not a sustainable eating program.

You're currently averaging 3lbs per week weight loss so to maintain that rate of weight loss in a healthy sustainable way and without shedding excess water you need to burn 1500 calories more than you consume. To find out how much energy you burn in a day find your Basal Metabolic Rate

Women: BMR = 655 + ( 4.35 x weight in pounds ) + ( 4.7 x height in inches ) - ( 4.7 x age in years )
Men: BMR = 66 + ( 6.23 x weight in pounds ) + ( 12.7 x height in inches ) - ( 6.8 x age in year )

Then multiply by 1.2 and add the number of calories burned through exercise per day. (If you're overweight then you calorie counter on your excerise machine will likely be in accurate, there are plenty of calculators online that will give you an indication based on age, weight and height)

Never reduce your calorie intake lower than 10calories per lb of idea weight. eg. If your ideal weight is 150lbs then your min calorie intake should be 1500 calories per day.
posted by missmagenta at 1:46 AM on May 22, 2007 [1 favorite]

When your muscles heal, your body has to burn something to do it. Of course, with a low enough amount of incoming calories, it must burn fat to do it.

If you don't rest, your muscles don't completely heal. When you rest every several weeks, it finally has this chance, and you see some weight loss, along with the water thing.

Frankly, you're probably wasting a lot of the fat burning you could be reaping from your workouts. It would be far more optimal to work out just a three of four days a week. This is not slacking.

Slow and steady wins the race, not crash dieting.
posted by poppo at 4:02 AM on May 22, 2007

three or four
posted by poppo at 4:03 AM on May 22, 2007

yeah, just go on light walks on your off days, just to maintain your routine.
posted by thinkingwoman at 5:49 AM on May 22, 2007

I don't know why your weight loss seems to come only when you don't exercise, but I do know that it is less than ideal to train 3 weeks out of four if you want to get in shape and lose weight. Your body needs time to recover from exertion, especially if you aren't used to it. However, the best time for recovery is the period from when the exertion stops to a couple days after. Taking a week off is not going to help you recover from exercise that happened three weeks prior. Spread your workouts over the full four weeks, with a day off every four or so days to recover. Since you are only lifting weights three times a week, you are getting enough recovery from that on the other days, so you can continue lifting all four weeks. I suspect that once you train more regularly you will see your weight loss even out.

My only guess as to why you aren't losing weight during your training periods is that you are increasing your calorie intake significantly during this period and haven't realised it. Are you keeping track of your caloric intake?
posted by ssg at 7:31 AM on May 22, 2007

jamjam: Excellent, thanks. This makes sense to me.

missmagenta: "high protein diet is dangerous and incredibly bad for your body" I appreciate your answer, but you're wrong on this. Prior to starting it in September I had blood work done. In January and in March when the blood was done again it improved across the board. Total improvement. I was concerned about calcium build up from what I read, so my doctor looked at my blood work, which was normal. He also had me do a 24 hour urine test and everything was fine. As for caloric intake, I track everything I eat so I can tell you I average 2108 calories a day. This is a running average over the last 30 days. "Low carb/high protein is not a sustainable eating program." You are probably right for most people, but I've been at it 7 months and nothing has gotten old ... in fact, it's helped me streamline my eating. Thanks again for the answer!

poppo: Interesting. Your explanation boils down to stressing out the body too much, so it never has a chance to catch up, right? Do you have any links related to this that mention the situation I am finding? Your answer is very intriguing.

ssg: I appreciate your answer. My caloric intake stays about the same, and yes, I do track it using Nutribase. You mentioned the weights being spaced out ok, but not the cardio. Am I really stressing that much during cardio that my body has to recover? I don't really change my cardio workout that often. Thanks again!

thinkingwoman: By light do you mean no incline and a speed of 2.0?
posted by zymurgy at 9:42 AM on May 22, 2007

It is possible you're simply overtraining and that's why you don't see any results until your week off? I'm certainly not an expert, but I know overtraining is a very common problem, especially with beginners. The definition of overtraining would vary greatly from one person to the next.

I follow a similar routine to yours, but I do 45 minutes of cardio every morning and then lift 4 nights a week (off on Wed, Sat. & Sun.). While I also notice my largest strength gains during my week off (approx. every 3 months), I make steady gains every week. If you have a lot of fat to lose, I would find it odd to make no progress except on your week off. I consistently lose 1-3 pounds a week while also gaining muscle. For the longest time it didn't seem like I was making any progress until I finally realized my scale sucked. I also take pictures of myself from the front and side every 2 weeks to track my changes in body composition. While I felt silly at first, this has proved to be extremely inspirational. The image in my mirror looks like the same old me but the pictures tell a different story. I highly recommend it.

I try to mix up my diet occasionally. I eat about 140 carbs a day (mostly at night after my second workout) and I continue to lose weight. Diets like Atkins weren't written for people performing frequent exercise including lifting heavy weight. Your body needs carbs for fuel. I would feel like total crap if I ate 20 carbs a day with my exercise routine. I don't see how you even get out of bed every morning. A weekly cheat meal is also essential to keep your body from adjusting to your diet.

A book I found very useful for general advice, lifting routines and diet (for weight lifting) is The New Rules For Lifting. It breaks everything down in black 'n' white and cuts out all the fancy crap. Another great book for developing your own routines and learning about the body is Strength Training Anatomy. I've spent countless hours browsing through this book (I know, I'm a loser).

As for missmagenta's comments, a high protein diet can be unsafe under certain conditions.
posted by bda1972 at 2:44 PM on May 22, 2007

bda1972: Thanks for the answer and sharing your activities. The scale sucked could be one of the things I should look into as well.

You raise an interesting point concerning the weights. Maybe it's time for me to move to free weights. I've read online that at a certain point your body becomes "used" to the machines. The Anatomy one looks fascinating and something I can dig into.

I prefer to understand what is happening in my body, so books like that help.

As for the low carb, as I said, it's worked for me like a charm. No issue with energy either. I've been under a doctor's watchful eye the entire time with the appropriate tests. No kidney or liver problems.

Your body can use protein and fat for fuel. Carbs are an easier way for it to use energy, though.

The pictures ... hmmm. I don't see it in pictures, but everyone around me sees it. I've noticed the loss in many other ways. Things I can do, where I can fit, etc.

The weekly cheat meal is something I haven't heard before. Is there a link you can pass on to explain the hows and whys behind that?

Again, thanks a ton for your information.
posted by zymurgy at 3:14 PM on May 22, 2007

Link 1
Link 2
Link 3

I would certainly consider switching to free weights. I started on machines and it can be a little intimidating to switch to free weights. Everybody seems like they really know what they're doing and you feel like a beginner all over again. After a while you realize that many of the people using free weights are clueless too. I would concentrate on learning proper form and worry about lifting tons of weight later. I really started to see strength gains when I switched to free weights. Plus, the possible variations on free weight exercises is huge (boredom is my enemy at the gym). Just like your diet, your muscles adapt to your routines so you need to change them every few months or so to continue strength gains. The first book I referenced covers all of these topics in detail.

While I agree your body can get fuel from multiple sources, carbs are a needed (at least for me) in addition to (good) fats and protein. Here's a pretty good article on low-carb diets and weight lifting. It's a tough call because there are expert opinions on every side of any argument and many of the weight lifting web sites are so full of ads you start to doubt their intentions. The key is to try a bunch of stuff and keep doing what works for your body.
Good luck!
posted by bda1972 at 3:47 PM on May 22, 2007

FYI: I forgot to mention that I spent my first year or so at the gym completely busting my ass doing cardio and lifting (only on machines and using the exact same routine) nearly every day and made almost NO progress. At first you can't help but make some progress because your body is used to watching TV all day and now it's actually moving but eventually it stops. It's amazing how quickly your body adapts. That's when I decided to learn about diet and the proper way to exercise (sadly, after I got discouraged, gave up and gained back 20 pounds). My point is that it is possible to bust your ass and still not lose weight or gain muscle.
posted by bda1972 at 4:03 PM on May 22, 2007

zymurgy: re: recovery from cardio. I don't know if you are stressing your body doing that amount and intensity, because I don't know your body. It depends on your fitness level. You may also be stressing your joints.

If you want to do cardio every day, why not switch it up a little and do 30 minutes one day, 40 the next, 50 after that and then take a day of relative rest on the fourth day and go 15 minutes (or some similar numbers)? If you want to increase your fitness level, then you will want to work to increase your workout length. With that sort of schedule you could go exercise all four weeks and minimize the risk of injury while maximizing the benefits of training. Another option would be to only go for shorter 15-25 minute workouts during the rest week.
posted by ssg at 4:59 PM on May 22, 2007

bda1972: I appreciate the time you took with the response. The articles look very informative, and bring to light information I didn't know. The more I am reading the more I am starting to believe my body is used to what I have done.

Your aside about seeing people in the free weights area is dead on. Intimidation is the real fear I have about that room. You are so right that it appears people already know what they're doing. Someone suggested two books above and I have those reserved at the library.

ssg: I never considered the length of the cardio. For some reason I've always believed it's your heart rate that is the key and not the length. I'm going to read more about your suggestion. But, based on your answer and bda's, I am starting to think my body has become used to the exercise I am tossing at it. Interesting. I wonder what medical process explains that.
posted by zymurgy at 8:43 PM on May 22, 2007