Farah Hameed, MD, a sports medicine physician with ColumbiaDoctors says “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 what happens when you swap your regular sweat sessions for never-ending Netflix nights—and how long it takes to re-flip the fitness switch.
Your brain might start to change after 1 week
According to one review in 2013, after the years of research, it was stated that exercise is good for your brain and it might be able to help offset age-related memory loss. Now, a new study in the journal Frontiers in Aging Neuroscience found that even a short vacation from your workout might cause changes to the brain. A group of long-term endurance runners voluntarily took a part in a research study and took a 10-day exercise break, their subsequent MRIs showed a reduction in blood flow to the hippocampus, the part of the brain that’s associated with memory and emotion. The researchers point out that although the runners didn’t experience any cognitive changes over the period, more long-term studies are needed.
Though human evidence is limited, rat studies presented at a recent Society for Neuroscience conference suggest animals that stop moving for just a week grow fewer new brain cells and do worse on maze tests than those who stick to a steady wheel-running routine.
You get winded so fast within 2 weeks
Within 2 weeks of avoiding the gym or skipping sweat sessions cause a drop in your VO2 max (a measure of fitness that assesses how much oxygen your working muscles can use) can drop by about 15%, and after three months, it can fall about 20%. “and those are conservative estimates,” Dr. Hameed notes.
If you recently started a workout plan like as a New Year’s Resolution, your fitness gains could actually evaporate completely. So, Staying even slightly active can help your endurance. One study on 2009 found that male kayakers who took a five-week break from their training saw an 11.3% drop on average in their VO2 max, while those who worked in a handful of exercise sessions during each week only saw a 5.6% drop. Dr. Hameed says “Even if you don’t notice a change in your speed or strength, you might experience a sharp rise in your blood pressure and blood glucose levels—something that could be more serious for people with diabetes or high blood pressure.”
One reason: You lose mitochondria or the mini-factories within your muscle cells that convert that oxygen into energy. In fact, in a recent British study, 2 weeks of immobilization decreased muscle mitochondrial content as much as 6 weeks of endurance training increased it.
Your strength will start slipping within 4 weeks
According to Dr. Hameed, some people will notice a decline in strength after about two weeks of hiatus, while others will begin to see a difference after about four weeks. Strength lingers longer than endurance once you stop training. But depending on just how slothful you’ve become, your quads and biceps may start to shrink soon after you leave the weight room. Our strength probably diminishes at a slower rate than our endurance. And on 2011 study in the Journal of Strength and Conditioning, it is found that when one group of men stopped doing resistance training, they still had some of their strength gains up to 24 weeks later.
You might gain fat within 8 weeks
“You need to do some type of everyday activity, ” says Dr. Hameed. According to her, after about six weeks of hiatus, people will start to notice a physical change looking in the mirror or at the number on the scale. Even elite athletes aren’t immune to the rebound. Koundourakis found super-fit, already-ripped pro soccer players gained a percentage point of body fat after taking 6 weeks off. And one study in 2012 in the Journal of Strength and Conditioning Research found that competitive swimmers who took a five-week break from their training experienced a 12% increase in their levels of body fat, and saw a boost in their body weight and waist circumference. Interestingly they were not totally inactive, they still did some light and moderate exercise. And a 2016 study found that elite Taekwondo athletes who took an eight-week hiatus from exercise experienced an increase in their levels of body fat and a decrease in muscle mass, too.
Conclusion: Just don’t quit moving altogether, continue cycling, using the elliptical, or even light walking. Your body, brain, and waistline will thank you.