What Happens When You Stop Working Out?

While regular exercise can change your body for the better—ceasing your regular workouts can have an equal and opposite effect rather quickly. According to research by the National Institutes of Health, fitness experts refer to this as “detraining,” a process that causes a partial or complete loss of anatomical, physiological and physical performance as a consequence of regular fitness training reduction or cessation. Detraining can result in decreased metabolism, weight gain, and increases in blood pressure and blood sugar. Luckily, the negatives can be quickly reversed by resuming your fitness regimen…

1. Muscle Shrinkage

According to Dr. Martin Gram, a PhD from the University of Copenhagen, although strength will remain longer than endurance if you stop weight training—muscle shrinkage can occur fairly quickly if you leave your iron-pumping workouts in the past.

Dr. Gram monitored the muscle mass decline in a group of individuals who ceased weight training and discovered the first signs of muscle mass shrinkage began appearing within 2 weeks of ceased workouts. You can rebuild your lost muscle mass, however, keep in mind that it will take longer to rebuild it compared to how long it took to lose it.

2. V02 Max Decline

There’s a reason why you struggle for breath when taking the stairs only a few weeks after missing your workouts. Dr. Nikolaos Koundourakis, a PhD from the University of Crete points out that your V02 max (or how much oxygen your muscles use) declines as fitness training decreases.

This is due to a decrease in mitochondria, the oxygen converters inside your muscle cells that produce energy. Dr. Koundourakis claims that cessation of fitness training can trigger muscle mitochondrial loss as soon as 2 weeks. However, you can gain it back within roughly 6-weeks of resuming regular endurance exercise once again.

3. Metabolism Slows

The reason why many people notice weight gain when they stop working out is largely due to a decrease in metabolism. Shockingly, Paul Arciero, an exercise science professor at Skidmore College, located in Saratoga Springs, New York, found that metabolism can slow significantly within a week of not working out.

Arciero monitored a group of college swimmers and found that lack of exercise increased their fat mass by roughly 12-percent. The study, featured in the Journal of Strength & Conditioning Research, recommends fitting in 1 workout per week to help maintain metabolism and resume full levels once you begin working out regularly once again.

4. Spiking Blood Pressure

Researchers at the University of Connecticut have linked just one day of missed exercise with increased blood pressure levels. This just goes to show how sudden and negative one day of sedentary activity is on our bodies. To make matters worse, one month of sedentary activity will slow blood vessel flow, stiffen arteries, and impact veins to the point where it appears as if you’ve never exercised at all.

Luckily, the same research team attests that you can resume your regimen of regular exercise and completely get blood pressure back to healthy levels within a week. Think of every day of exercise as a way to efficiently lower blood pressure and increase blood vessel flexibility.

5. Brain Drain

We all know that regular exercise impacts more than our physical body—it affects our mood and brain as well. A research study published in the journal Brain, Behavior, and Immunity, tested this theory on lab rats and discovered that animals who were sedentary for a week produced fewer amounts of fresh brain cells.

The study also showed that the sedentary lab rats performed worse on maze tests versus rats those who performed regular physical activity (i.e.,wheel-running). Regular exercise has long been linked to lower rates of depression. Research published in the journal, Abnormal Psychology, even found that regular exercise in older adults (i.e., walking, swimming, cycling) improved memory by promoting a larger hippocampus (the brain’s memory center).

6. Rise in Blood Sugar

We all crave rest and relaxation. However, too much slothfulness will increase blood glucose, and increase the risk of diabetes and heart disease, according to researchers at the University of Missouri. You can imagine how detrimental this is if you already suffer from type 2 diabetes or cardiovascular disease?

A study published by the journal of Medicine & Science in Sports & Exercise found that post-meal blood sugar levels spiked due to continued sedentary lifestyle (approximately 5 days of no exercise). The study outlined that typically blood glucose naturally rises after you eat, but drops with activity as muscles and bodily tissues absorb sugar for energy. It’s this gradual accumulation of glucose that raises the risk of diabetes and cardiovascular disease.


Emily Lockhart

Emily Lockhart is a weight loss expert who specializes in healthy living. She is dedicated to providing health-conscious individuals with the information they need to make great lifestyle choices that will make them look and feel better. In her spare time, Emily teaches Pilates at a local studio and enjoys activities like hiking, rowing and biking.