There comes a point when you consider throwing in the towel after a workout—both figuratively and literally. Blame it on your looming work deadlines, or the stubborn needle on the scale, or even just plain old boredom. (We are not mentioning the age thing…)

 That’s normal.  There are plenty of benefits to exercise, but they’re not permanent. In fact, many of those hard-earned gains will start to disappear in as little as two weeks.

Here’s exactly what you can expect to happen to your body if you give up exercise:

Within 10 days: Your brain might start to change

For years, researchers have suspected that exercise is good for your brain, too—according to one 2013 review, it might be able to help offset age-related memory loss. Now, a new study found that even a short vacation from your workout might cause changes to the brain.

All this comes down to, is that after 10 days, there is less  blood flow to the part of the brain that’s associated with memory and emotion.

Within two weeks: Your endurance will plummet and your vitals may spike

After just 14 days, you might have a harder time climbing a flight of stairs. The reason you’re so winded? Skipping sweat sessions causes a drop in your VO2 max (the maximum or optimum rate at which the heart, lungs, and muscles can effectively use oxygen during exercise, used as a way of measuring a person’s individual aerobic capacity.), or the maximum amount of oxygen your body can use. It can dip by about 10% after two weeks. It only gets worse from there: After four weeks, your VO2 max can drop by about 15%, and after three months, it can fall about 20%—“and those are conservative estimates.

Within four weeks: Your strength will start slipping

Some people will notice their strength declining after about two weeks of inactivity, while others will begin to see a difference after about four weeks. The silver lining: Our strength probably diminishes at a slower rate than our endurance.

Within eight weeks: You might gain fat

You will start to notice a physical change—either by looking in the mirror, or at the number on the scale—after about six weeks. Even elite athletes aren’t immune to the rebound.

So the moral of the story is:  NEVER stop exercising if you can help it!