You Might Appear To Be Gaining Weight The Day After Exercise If Not Exercising On That Second Day

The 4 days mentioned below include today’s results. Today is also the first time I gained weight on a snacks-only diet with a 90-minute run. Overall, the record is great, although the average loss on such days looks like it will be less than I was hoping for. That is because of the phenomenon discussed in detail in this blog post.

Day 1: 79.1 to 78.6 (lost .5 kg); non-exercise portion – gained .6
Day 2: 78.6 to 78.0 (lost .6 kg); non-exercise portion – gained .4
Day 3: 78.0 to 77.7 (lost .3 kg); non-exercise portion – gained .6
Day 4: 77.7 to 77.8 (gained .1 kg); could not measure non-exercise portion
average: .325 kg of weight loss; non-exercise average – gained .53 kg

For this blog post, I am going to be describing a scenario that you might encounter over the course of 2 days. To keep it as clear as possible, I will refer to these as Day 1 and Day 2.

Day 1 – exercise day (with substantial exercise, not just a super light workout)
Day 2 – day with no exercise

In a perfect dieting and fitness world, we would all ideally be exercising every day. But we know that is not always possible and not even desirable since the body does need rest.

You will have many situations where you exercise on Day 1 and do not exercise on Day 2. The scenario I am describing here involves substantial exercise, not just a short stroll in the park with the puppy dog. In my case, that is running 90 minutes and losing about 2 pounds during that session. It is actually about 1.0 kg or slightly more. I will just say 1.0 kg for this example.

I will just use estimates of the numbers I have so far on the snacks-only diet. These are estimates only:

Scenario 1

When not actively exercising, I more or less break even on a snacks-only diet. So Days 1 and 2 would typically look like this with no exercise at all, including no exercise before Day 1. Note that exercise right before Day can totally change these numbers. I mean no exercise even on the days leading up to Days 1 and 2.

Day 1: break even
Day 2: break even

Note that daily results always vary, so the above are average days.

Scenario 2

Now, imagine that I decide to exercise on Day 1 at the end of the tracking day but have not exercised for a week or so before Day 1. This is important. These numbers do not apply if you exercised right before Day 1. Also, in this example, you do not exercise on Day 2.

Day 1: lose 1.0 kg (exercise day at the end of the day)
Day 2: gain .5 kg (no exercise)

I will explain scenarios 2 and 3 together below.

Scenario 3

Now, imagine that you exercise for several days before Day 1 and continue to exercise on both Days 1 and 2.

Day 1: lose .5 kg (exercise day when you have exercised every day for several days before this)
Day 2: lose .5 kg (another exercise day)

OK. So why was Day 1 in Scenario 2 so good? It was because the exercise on that day is not going to show how the body adjusts to exercise. That adjustment (water retention or whatever it is) will show up on Day 2, not Day 1. That is because the exercise session was at the very end of your tracking day.

On Day 2 in Scenario 2, it shows you actually gaining weight. So why did you gain .5 when you usually break even with no exercise? This is the body adjusting to exercise in Day 1. At first blush, this may look bad to you. But dive into the numbers to see the actual results.

Scenario 1 with no exercise at all: break even
Scenario 2: lose 1.0 kg + gain .5 kg = a weight loss of .5 kg

See what happened? Yes, you gained on Day 2, but you still lost .5 kg when combining Days 1 and 2.

Scenario 3 shows an average loss of .5 kg and a total loss of 1.0 kg. Why is it twice as good as Scenario 2? Because you exercised 2 times in Scenario 2. It’s as simple as that. You got double the results due to double the exercise.

In Scenario 2, if you exercise on Day 2, you would actually lose 1.5 kg. However, the added .5 kg of weight loss would only be for that one scenario. And the first day you do not exercise, you would lose that additional .5 kg. So it evens out over time to an average of .5 kg per day.

no exercise before
Day 1: lose 1.0 kg (exercise for the first day in a while)
Day 2: lose .5 kg (exercise again)

It looks at this point that you have magically lost an extra .5 kg. That is not true unless you exercise every day for the rest of your life.

Day 3: lose .5 kg

Now, on Day 4, you need a break.

Day 4: gain .5 kg (no exercise)

Do the math, and you will see that it now works out:

lose 1.0
lose .5
lose .5
gain .5

The total loss is 1.5 on 3 days of exercise. That is an average of exactly .5 kg. There is no magic here. It’s just that the average is different until the first day that you do not exercise.


Now, how do you apply this to your situation? The way you apply it is to exercise on some days and not exercise on others and track all those results. Use Scenario 2 above and make sure that the amount you lose on Day 1 (exercise day) is more than the amount you gain on Day 2 (non-exercise day). Get several weeks of results to make sure you have at least a decent estimate.

If you like to work out almost every day, then you can also use Scenario 3 and just take the average. But be aware you are likely to gain a little on the first day you do not exercise. This must be factored into your results. It may be negligible if you take almost no break days. But if you take 2 break days a week or more, then it becomes crucial to factor in how much you gain back on those off days.

Let me give the last piece of this puzzle. None of this matters all that much if you have a diet that allows you to break even with no exercise AND you are able to maintain that diet without overeating even when adding exercise. If you can do that, then the exercise is a bonus that will allow you to lose weight, at least until there is no excess body fat left to lose. At that point, the non-exercise portion is pretty much just a statistic. In the meantime, it’s always good to know how your body reacts to exercise so you can understand the results you are getting. It’s not exactly intuitive to me, so I was surprised to see how the numbers work in reality. But it ends up being good in the long run, at least for me. And that is because I am able to maintain my diet even when exercising.

Note: I still have cheat days and make mistakes. That is the other value of exercise. It allows you to recover from those cheat days and mistakes.


Today, I am experiencing the same thing I have seen the past 3 days. After a run to finish the previous day, I start following the snacks-only diet and drink plenty of water. The weight stays in my body, and I am once again not peeing much yet. In periods of non-exercise, I pee like a racehorse on the snacks-only diet. That completely changes when adding a 90-minute running session.

This tendency is not easy for me to get used to because it’s not what happened when testing the snacks-only diet with no exercise. In that case, the weight would go up and then back down pretty quickly. But it doesn’t go down much at all or at least slowly goes down after these 90-minute jogging sessions.

I was already at about 1.0 kg over even before the 3rd snack. This kind of thing doesn’t make me feel relieved. But I must have this water to survive, and it’s even more vital after a long run. So I am just going to have to get accustomed to it and watch my actual food intake closely to ensure that I am eating snacks only. The water weight will have to take care of itself on its own time.

Today will be my first day without tracking the non-exercise portion. To do that tracking, I must be free to check my weight directly before exercising. Unfortunately, my schedule for the next few weeks is not going to allow me to do that unless I were to cut one day really short. I don’t want to mess up my tracking like that right now because I am right in the middle of determining how many days it takes to lose down from 79.1 to 75.0 kg.

There will be plenty of time later to test the non-exercise portion of exercise days. For now, suffice it to say that every single one of these marks has shown a weight gain – bar none. But every single day with exercise on the snacks-only diet has shown a loss even with the gain from the non-exercise portion. You can’t ask for much better than 100% success when measuring by the day in this manner. Of course, I will eventually hit some bad day and gain weight despite exercising. That is bound to happen. But the success rate is literally 100 so far in 6 days.

I was still about 1.0 kg over after the 3rd snack. It is clear that I am doing fine on my actual diet in terms of food. And the water weight is apparently starting to reduce now. It probably helps that I am not drinking coke today. LOL. Yesterday was not a disciplined affair.

I am taking in large amounts of water, and it is showing on the scale. After the 4th snack, I was at 79.4 kg. We’ll see what happens with this by morning. It’s even higher than yesterday’s max increase. But I am almost positive that this is not a matter of overeating.

Nothing is changing here after another hour. I am at 79.4. Nothing else to do at this point but to wait and have at least one more small snack. I can totally understand large increases due to water, but what I am not understanding is how the weight doesn’t seem to start coming back down for hours. This is so different than the days I have tracked without exercise because my weight fell so fast on those days between snacks. It’s still not clear to me yet whether this is a normal change due to the substantial added exercise, but I presume it is.

I finally got back down some to 79.2 kg. It would really behoove me to stop worrying about the total weight and focus more on just the food. This water is going to take care of itself. I am in the process of readjusting my expectations on this. It is so different than what I am used to seeing under any other diet. My “max increase” may have to be disregarded in this scenario (snacks-only diet with loads of water when doing 90-minute running sessions). I’m not going to go back over my max increase in this post, but there is plenty about it elsewhere in this blog.

A little after the final snack, I was at 79.3 kg. That is 1.6 over the 77.7 starting weight. This is the most I have seen while doing the snacks-only diet. But I know a lot of it is water, so I’ll just wait and see what happens with it overnight and for the rest of this 24-hour period. I’ll be running early and then waiting a few hours before the official weigh-in at about 12 noon.

A couple of hours after my last snack, my weight got down to 79.0. Now, that is the way my body usually acts. It seems there is a delayed effect with this diet-exercise combination. However, it seems doubtful that I could get down to breakeven without exercise.

I woke up early and went to the bathroom and then weighed in at 78.7. This was at 5:30 in the morning. That is still a low rate of drop of way less than .1 kg per hour. However, I have 6 1/2 hours left until the official weigh-in. I will almost definitely be losing weight again today because the run should reduce my weight by approximately 1.0 kg. That will put me at close to even. Then, whatever naturally falls off over the next 6 1/2 hours is the amount I will lose today.

After the run and peeing, I was down to 77.6 kg. That left 4 more hours until the weigh-in. So I’ll definitely be losing weight today and keeping the streak of 7 days alive. Interestingly, that is 7 days of weight gain pre-exercise and 7 days of loss after exercise. While I don’t have the exact non-exercise result today, it almost certainly would have been way over. But I can officially say that all 7 snacks-only days with exercise have been a weight loss.

This wait is a very slow burn. With 2 1/2 hours to go, I was still only down to 77.5. This is positive weight loss, but I was expecting more. I really did not eat that much yesterday. Maybe I am just expecting too much too fast. Also, there may be a major correction soon that shows a day with huge weight loss. Meanwhile, I am at least happy to be back in the mid 77 range and moving in the right direction.

As far as today goes, I have about had it and just want it to be over. I checked with 2 hours to go, and the scale actually said 77.6. I am literally stuck in place here, and it appears that my body is destined to keep the weight on for a while longer. At least it is going to be a weight loss even if it is a small one. I don’t remember seeing anything like this. It’s crazy stuff.

Wow. This is why you don’t count your chickens before they hatch. The previous weigh-ins were done quickly, which sometimes causes bad readings. After checking carefully at 12 noon, my weight was 77.8 kg. I actually gained .1 kg today. That ends the streak I was talking about above. And this also ends one of the strangest days I have ever experienced. It’s like there was a magic hand preventing me from losing weight. Well, it’s not good to worry about a one-day result. This will probably take care of itself within a day or so.


Here are my recent daily and overall stats for the snacks-only diet with and without exercise:

Day 35 – lost .2 kg
Day 36 – lost 1.0 kg
Day 37 – gained .6 before exercise; lost .5 including exercise
Day 38: gained .4 before exercise; lost .6 kg including run
Day 39: gained .6 before exercise; lost .3 kg including exercise
Day 40: gained .1 kg including run (could not track before exercise)

“No Exercise Days” (or non-exercise portion before running) when no exercise the day before – lost .1 kg – 34 days
Exercise Days: lost 3.6 kg – 7 days
30-min Days: lost .3 kg – 1 day
90-min Days: lost 3.3 kg – 6 days
Non-Exercise Portion On Days After Exercise: gained 1.5 kg – 4 days

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