Just 14 Days of Inactivity Can Cut Your Fitness Level by 4 Percent

Photo credit: skaman306 - Getty Images
Photo credit: skaman306 - Getty Images
  • Preliminary research recently presented at this year’s Annual Meeting of the European Association for the Study of Diabetes (EASD) in Barcelona, Spain, found that inactivity even for a short period can lead to metabolic problems.

  • Two weeks of inactivity also decreased fitness levels by 4 percent.

  • It took 14 days of training to see fitness levels return to what they were at before the sedentary period.


Ever skipped a ride one day only to find that short-term break stretch into weeks without a workout? Or maybe you’ve been sidelined with an injury and are wondering how that hiatus will take a toll on your overall fitness.

It’s no surprise that an exercise break could mess with your fitness, but did you ever wonder how much—and how long it takes to happen? Research conducted at the University of Liverpool in the U.K. sought to answer that question.

In the preliminary study, which was presented at this year’s Annual Meeting of the European Association for the Study of Diabetes (EASD) in Barcelona, Spain, 28 individuals who typically walked over 10,000 steps per day reduced their steps by around 10,000 steps—meaning, becoming almost completely sedentary—and swapped walks or other forms of exercise for an additional 103 minutes of sedentary time per day.

After 14 days, the researchers analyzed the participants’ overall fitness levels, which they measured through a combination of VO2 peak (how efficiently oxygen is used during peak exercise effort) and cardiovascular function by blood vessel health. They discovered that their cardiovascular function decreased by nearly 2 percent and VO2 peak decreased by 4 percent, leading to an overall fitness levels drop of as much as 4 percent.

What’s more, their metabolic health took a dip, too: Their total body fat increased by 0.5 percent, waist circumference by one-third of an inch, and liver fat by 2 percent. They also became more insulin resistant, a condition where your body does not respond as readily to insulin as it should, causing excess blood sugar to build up in your bloodstream and raising your risk of type 2 diabetes.

These negative health effects are likely a product of muscle underuse: When you stop exercising, your muscles contract less frequently, and you reduce the activation of an enzyme called AMPK, which aids blood sugar absorption for fuel, Kelly Bowden Davies, Ph.D., professor of Sport and Exercise Science at Newcastle University, U.K told Runner’s World.

The lack of shear stress, or the heavier force of blood flow on vessel walls during exercise, may contribute to poorer blood vessel health. That’s because the more you exercise—and get your blood pumping—the healthier your heart and arteries will likely be.

But that doesn’t mean you should panic if you let a few weeks of training slip away from you. The researchers also studied how long it takes to get this fitness back, and those results were a little more encouraging.

After the participants resumed exercise, the researchers again tested their fitness levels 14 days later—the same amount of time that they rested—and found that they had returned to their baseline.

The best way to offset these health consequences is to be sure to engage in habitual physical activity, according to the study. So even if you can’t do your regular workout, simply getting a small boost of exercise during the day, such as getting out for a walk at lunch, can help.

But even if you are sidelined with an injury for a couple weeks—or circumstances temporarily take you away from your workout routine—your fitness levels should bounce back quickly when you resume.

You Might Also Like